tag:theconversation.com,2011:/us/topics/zika-18991/articlesZika – The Conversation2023-08-18T13:16:43Ztag:theconversation.com,2011:article/2117032023-08-18T13:16:43Z2023-08-18T13:16:43ZHow genetically modifying mosquitoes could strengthen the world’s war on malaria<figure><img src="https://images.theconversation.com/files/543058/original/file-20230816-19-7rtxgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Genetic modification could make malaria-carrying mosquitoes harmless.</span> <span class="attribution"><span class="source">LeliaSpb/Getty Images</span></span></figcaption></figure><p>It’s been 126 years since British medical doctor Sir Ronald Ross <a href="https://www.nobelprize.org/prizes/medicine/1902/ross/facts/">discovered</a> that mosquitoes in the <em>Anopheles</em> family are primarily responsible for transmitting malaria parasites between vertebrate hosts. </p>
<p>Since his discovery, mosquitoes have been found to carry and transmit <a href="https://theconversation.com/mosquitoes-theres-malaria-plus-5-other-diseases-they-pass-on-to-humans-188856">many other diseases</a> that pose a major threat to public health. <a href="https://theconversation.com/mosquitoes-theres-malaria-plus-5-other-diseases-they-pass-on-to-humans-188856">Among them</a> are yellow fever, dengue and <a href="https://theconversation.com/understanding-zikas-silent-presence-in-africa-is-key-to-tackling-the-next-epidemic-80343">Zika</a>.</p>
<p>Currently, malaria is the most lethal mosquito-transmitted disease. The World Health Organization (WHO) <a href="https://www.who.int/news-room/fact-sheets/detail/malaria">reported</a> an estimated 247 million cases of malaria worldwide in 2021 and 619,000 deaths. <a href="https://www.who.int/news-room/fact-sheets/detail/malaria">Almost all cases and deaths</a> were in African countries.</p>
<p>Other diseases transmitted by mosquitoes are also a source of immense human suffering. It is <a href="https://www.worldmosquitoprogram.org/en/learn/mosquito-borne-diseases#:%7E:text=Common%20types%20of%20mosquito%2Dborne,chikungunya%2C%20yellow%20fever%20and%20Zika">estimated</a> that dengue infects about 390 million people annually. And thousands are affected by Zika, chikungunya and yellow fever. </p>
<p>Insects that transmit diseases to humans are known as vectors and the diseases they transmit are referred to as vector-borne diseases. These diseases are very difficult to control. They generally have complex life cycles, involving both the insect and the human host.</p>
<p>Conventional methods to control vector-borne diseases have targeted the vectors, focusing on reducing their opportunities to come into contact with humans. </p>
<p>This is <a href="https://www.who.int/teams/global-malaria-programme/prevention/vector-control#:%7E:text=Vector%20control%20is%20a%20highly,areas%20at%20risk%20of%20malaria">particularly true for malaria</a>. Insecticide-treated nets serve a dual function by acting as a physical barrier between the mosquito vector and humans, and exposing the mosquito to a lethal dose of insecticide when it lands on the net. In another common control method, mosquitoes are exposed to a lethal dose of insecticide through indoor residual spraying.</p>
<p>Both nets and indoor spraying have played <a href="https://endmalaria.org/sites/default/files/Kleinschmidt%20Immo_IRS%20and%20ITN%20combined%20effect.pdf#page=7">a major role</a> in reducing African countries’ malaria burden. But their sustained efficacy is under threat. Many vector populations have <a href="https://www.who.int/teams/global-malaria-programme/prevention/vector-control/insecticide-resistance">become resistant</a> to the insecticides used in these methods. They have also <a href="https://www.pbs.org/wgbh/nova/article/mosquito-behavioral-resistance/">changed their behaviours</a> to reduce their contact with those insecticides. </p>
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<a href="https://theconversation.com/fresh-signs-of-mosquito-insecticide-resistance-in-south-africa-181618">Fresh signs of mosquito insecticide resistance in South Africa</a>
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<p>Scientists <a href="https://www.ivcc.com/research-development/insecticide-discovery-and-development/">are working</a> to address these issues. But other methods that don’t rely on insecticides are needed in the fight against mosquito-borne diseases. </p>
<p>That’s where genetic modification comes in. We are researchers focused on finding novel ways to advance malaria elimination efforts and are excited about recent advances in genomic research that make genetic modification a realistic option for malaria control in particular. As with other approaches to controlling or eventually eradicating the disease, this won’t be a complete solution. But it’s got the potential to strengthen the global fight against malaria.</p>
<h2>Genetic modification for malaria control</h2>
<p>Mosquitoes can be genetically modified through two different technologies. The first method, <a href="https://surface.syr.edu/cgi/viewcontent.cgi?article=1142&context=eli">paratransgenesis</a>, involves infecting mosquitoes with bacteria that prevent them from transmitting malaria. This doesn’t harm the mosquito. It is important not to eliminate or harm mosquitoes because they pollinate many plants and are <a href="https://www.reconnectwithnature.org/news-events/the-buzz/world-without-mosquitoes-not-as-easy-as-it-seems/">food</a> for animals like bats, birds and reptiles.</p>
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Read more:
<a href="https://theconversation.com/curious-kids-what-would-happen-if-all-the-mosquitoes-in-the-world-disappeared-175528">Curious Kids: What would happen if all the mosquitoes in the world disappeared?</a>
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<p>Scientists are excited about this method following the <a href="https://www.ft.com/content/c4db7776-e776-4717-bf9d-7792d5ff0ad0">recent discovery</a> of a bacterium that occurs naturally in mosquitoes’ guts and appears to prevent the malaria parasite from developing inside the mosquito.</p>
<p>The second method involves genetically modifying the mosquitoes themselves. This approach centres on <a href="https://www.synthego.com/blog/gene-drive-crispr">gene drives</a>: genetic systems that ensure genes of interest are inherited by all offspring in every generation. There are two types of gene drive. One aims to reduce the vector population size and is known as population suppression. The other aims to prevent the mosquito from transmitting malaria; it is known as population modification.</p>
<p>Gene drives focusing on population suppression have <a href="https://www.isaaa.org/kc/cropbiotechupdate/gdn/article/default.asp?ID=19494">shown great promise in laboratory studies</a>. They’ve yet to be tested in the field, though. </p>
<p>Population modification potentially has fewer environmental effects and is less prone to developing mutations. But it has proved more challenging to achieve and has not progressed as far as the suppression approach.</p>
<h2>Addressing scepticism</h2>
<p>It will be a while before this technology is routinely used by malaria control programmes. But preparation is under way. </p>
<p>Over the past decade, malaria control programmes have expressed a willingness to use genetic modification if and when such techniques are shown to be safe and acceptable to the affected communities. This has prompted the WHO <a href="https://www.who.int/news/item/19-05-2021-who-issues-new-guidance-for-research-on-genetically-modified-mosquitoes-to-fight-malaria-and-other-vector-borne-diseases">to provide guidance</a> on the use of genetically modified mosquitoes to control malaria and other vector-borne diseases.</p>
<p>In its guidance, the WHO acknowledges how crucial community engagement will be to the success of any future gene drive interventions.</p>
<p>This is important in an environment where there is <a href="https://theconversation.com/the-reasons-for-science-skepticism-can-be-complex-and-founded-on-real-concerns-171000">marked scepticism</a> about science, and particularly about genetically modified organisms (GMOs). In 2003, community resistance resulted in the rejection of genetically modified golden rice <a href="https://www.un.org/africarenewal/magazine/february-2003/controversy-rages-over-gm-food-aid#:%7E:text=Many%20Zambians%20believe%20that%20GMOs,in%20people%20with%20poor%20health.">in Zambia</a>, despite the country experiencing a pronounced food shortage. </p>
<p>More recently, there was backlash against the COVID-19 mRNA vaccines, which some people <a href="https://www.health.gov.au/our-work/covid-19-vaccines/is-it-true/is-it-true-can-covid-19-vaccines-alter-my-dna">suspected</a> of being capable of altering human DNA (it isn’t). </p>
<p>It is critical that the concerns of communities where genetically modified mosquitoes are to be released are addressed prior to any release. This will help promote acceptance and understanding of the new technology.</p>
<h2>Considerable investment</h2>
<p>However, community acceptance is not the only challenge. There is an urgent need for research on the relevant local malaria mosquito species so that the required genetically modified mosquitoes can be developed. Once the genetically modified lines are established, impact in the field must be demonstrated and systems established to ensure suitable numbers of mosquitoes can be reared and safely transported to the intervention sites. </p>
<p>All this requires considerable human resources and funding, suggesting that it will be some time before gene drive systems have real-world impact on malaria transmission.</p>
<p>Still, as the globe marks <a href="https://nationaltoday.com/world-mosquito-day/">World Mosquito Day</a> on 20 August, in honour of Sir Ronald Ross’s discovery almost 130 years ago, we believe there is reason for optimism: novel technologies like genetic modification have the potential to play a major role in the fight against malaria.</p><img src="https://counter.theconversation.com/content/211703/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shüné Oliver receives funding from the National Research Foundation of South Africa, the South African Medical Research Council and the Female Academic Leadership Fellowship of the University of the Witwatersrand. She is affiliated to the Wits Research Institute for Malaria at the University of the Witwatersrand. </span></em></p><p class="fine-print"><em><span>Jaishree Raman receives funding from Bill and Melinda Gates Foundation, Global Fund, CHAI, South African Medical Research Council, South African Research Trust, National Research Foundation and the National Institute for Communicable Diseases. She is affiliated with the Wits Research Institute for Malaria, University of Witwatersrand and UP Institute for Sustainable Malaria Control, University of Pretoria.</span></em></p>Methods that don’t rely on insecticides are needed to bolster the fight against mosquito-borne diseases.Shüné Oliver, Medical scientist, National Institute for Communicable DiseasesJaishree Raman, Principal Medical Scientist and Head of Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research, National Institute for Communicable DiseasesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1910332022-09-23T15:03:24Z2022-09-23T15:03:24ZDengue in France: tropical diseases in Europe may not be that rare for much longer<figure><img src="https://images.theconversation.com/files/486068/original/file-20220922-34615-sikp9n.jpg?ixlib=rb-1.1.0&rect=4%2C9%2C3282%2C2346&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/asian-tiger-mosquito-side-view-1264209730">Itsik Marom/Shutterstock</a></span></figcaption></figure><p>Dengue, a viral infection spread by mosquitoes, is a common disease in parts of Asia and Latin America. Recently, though, France has experienced an outbreak of <a href="https://www.connexionfrance.com/article/French-news/Health/France-warns-of-increased-risk-of-dengue-fever-from-tiger-mosquitoes">locally transmitted dengue</a>.</p>
<p>Dengue symptoms can include a fever, headache, joint pain, nausea and a red rash. Occasionally, though, it can lead to more severe disease – and even death.</p>
<p>Every year, France records a number of imported cases of dengue, where people have travelled to a country where dengue is endemic and brought the disease back with them. If a <a href="https://www.pasteur.fr/en/research-journal/news/tiger-mosquito-france-58-departements-red-alert">tiger mosquito</a> (<em>Aedes albopictus</em>) then bites the infected person, it can pass the infection on to someone who hasn’t travelled to an at-risk country. But it won’t transmit between people.</p>
<p>Since 2010, when local dengue transmission was first identified in France, there have been <a href="https://www.connexionfrance.com/article/French-news/Health/France-warns-of-increased-risk-of-dengue-fever-from-tiger-mosquitoes">around 12 cases a year</a>. However, since July 2022, there have been <a href="https://theconversation.com/les-cas-de-dengue-explosent-en-france-metropolitaine-que-faut-il-savoir-190729">nearly 40 cases</a> of locally transmitted dengue. And the French health authorities have warned of <a href="https://www.connexionfrance.com/article/French-news/Health/France-warns-of-increased-risk-of-dengue-fever-from-tiger-mosquitoes">more cases to come</a>. </p>
<p>One difficulty with controlling the spread of dengue is that the mosquitoes that spread it are active in the day and at night. The mosquitoes that spread malaria, on the other hand, are mainly active at night, so <a href="https://www.unicef.org/supply/stories/fighting-malaria-long-lasting-insecticidal-nets-llins">bed nets</a> are an effective way of reducing the risk of getting malaria in countries where the disease is endemic. But this control measure wouldn’t be as effective against dengue.</p>
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<img alt="Boy under a bed net" src="https://images.theconversation.com/files/486285/original/file-20220923-22-1bz36l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/486285/original/file-20220923-22-1bz36l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/486285/original/file-20220923-22-1bz36l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/486285/original/file-20220923-22-1bz36l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/486285/original/file-20220923-22-1bz36l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/486285/original/file-20220923-22-1bz36l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/486285/original/file-20220923-22-1bz36l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Bed nets are effective against malaria. Less so against dengue.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/little-african-boy-mosquito-net-protection-1812244213">Riccardo Mayer/Shutterstock</a></span>
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<h2>Climate change</h2>
<p>Mosquitoes spread many infectious diseases, including malaria, West Nile virus, yellow fever, Zika and chikungunya. These diseases are prevalent in areas that can be inhabited by mosquitoes. Habitats are often tropical areas across sub-Saharan Africa, South America or Asia. Transmission is via the mosquito bite, rather than person to person.</p>
<p>Climate change is having, and will continue to have, a significant effect on human and animal populations around the globe. Modelling has <a href="https://elifesciences.org/articles/55619">predicted</a> that changing temperature and rainfall across Africa could promote new habitats for mosquitoes to breed and, for example, increase yellow fever deaths by up to 25% by 2050. As a result, environmental risks are a <a href="https://www.who.int/initiatives/eye-strategy">core component</a> of the 2026 WHO Global Strategy to Eliminate Yellow Fever Epidemics. By 2030, the population at risk of <a href="https://malarianomore.org.uk/world-environment-day">malaria</a> in Africa will have increased by over 80 million, mainly as a result of climate change.</p>
<p>Mosquitoes cannot <a href="https://www.sciencedirect.com/science/article/pii/S0075951113001011">fly very far</a>, with distances ranging from a few metres to tens of kilometres. Imported cases of malaria or dengue are already common in returning travellers, but there is typically no local threat to the rest of the population. Despite this, the emerging threats from mosquito-driven diseases extend beyond the tropics. </p>
<p>Indeed, there have been over 570 cases of <a href="https://www.ecdc.europa.eu/en/publications-data/west-nile-virus-europe-2022-human-cases-updated-7-september-2022">West Nile virus</a> recorded in Europe this year. Most of these have been recorded in Veneto, in northern Italy. </p>
<p>It seems that the <a href="https://www.euronews.com/next/2022/08/11/cases-of-mosquito-borne-west-nile-fever-are-soaring-in-italy-this-is-what-you-need-to-know">lowlands</a> of Veneto are emerging as an ideal habitat for the <em>Culex</em> mosquitoes, which can host and transmit West Nile virus.</p>
<p>Globalisation and climate change have spurred the re-emergence of old diseases in new places. And public health authorities are taking these threats seriously. The <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/887925/National_contingency_plan_for_invasive_mosquitoes.pdf">UK Health Security Agency</a> has a national contingency plan for invasive mosquitoes. </p>
<p>As part of their fieldwork <a href="https://www.telegraph.co.uk/global-health/science-and-disease/why-official-mosquitoes-hunters-kent-fear-new-surge-malaria/">activity</a>, entomologists visit sites such as marshlands in the Thames Estuary in Kent. There, they catch mosquitoes and ticks and take them back to the laboratory for testing. This approach can help identify if the local insect populations are harbouring anything new, such as malaria or dengue, before it starts to spread.</p>
<h2>Vaccines</h2>
<p>The long-term future for the UK and other parts of Europe could require wider use of public health control measures, such as mosquito nets or insect sprays. Vaccine development is also likely to be critical as a preventive measure. </p>
<p>Yellow fever is already <a href="https://www.who.int/news-room/fact-sheets/detail/yellow-fever">vaccine-preventable</a>, and there are now licensed vaccines against <a href="https://www.un.org/africarenewal/magazine/july-2022/historic-funding-expand-roll-out-first-ever-malaria-vaccine-africa">malaria</a> being used in parts of sub-Saharan Africa. </p>
<p>Dengue vaccine candidates are <a href="https://www.cdc.gov/vaccines/vpd/dengue/public/index.html">emerging</a>, with one being licensed in the US. However, it comes with <a href="https://www.science.org/content/article/new-dengue-vaccine-should-only-be-used-people-who-were-previously-infected-who-says">recommendations</a> it should only be used in people who have already had dengue. This limits any widespread roll out.</p>
<p>There are huge numbers of people already at risk of mosquito-driven disease, and global inequities mean that poorer countries are <a href="https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(21)01787-6.pdf">most vulnerable</a> to climate change. The world needs to take seriously the threat of new diseases such as Zika, and neglected diseases, such as dengue. Populations at risk are only likely to increase over the coming years and decades.</p>
<p><em>Correction: An earlier version of this article stated that mosquitoes cause onchocerciasis (river blindness). This has been removed. Blackflies cause river blindness, not mosquitoes.</em></p><img src="https://counter.theconversation.com/content/191033/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Head has previously received funding from the Bill & Melinda Gates Foundation and the UK Department for International Development.</span></em></p>France experienced its largest outbreak of ‘native’ dengue this summer. Thanks to climate change, Europe can expect more of the same.Michael Head, Senior Research Fellow in Global Health, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1888562022-08-18T14:11:44Z2022-08-18T14:11:44ZMosquitoes: there’s malaria, plus 5 other diseases they pass on to humans<figure><img src="https://images.theconversation.com/files/479588/original/file-20220817-16-p6zz3e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Tacio Philip Sansonovski/Shutterstock</span></span></figcaption></figure><p>Most people instantly associate mosquitoes with malaria. But these tiny flying insects can transmit a number of <a href="https://www.who.int/news-room/fact-sheets/detail/vector-borne-diseases">other diseases</a> too. </p>
<p>Viruses transmitted by insects like mosquitoes are called arthropod-borne or arboviruses. Like malaria, these viruses are transmitted to vertebrate hosts through the <a href="https://www.medicalnewstoday.com/articles/311485">bite of a female mosquito</a> when she takes a blood meal to assist with her egg development. Most vertebrate hosts for these arboviruses are non-human. They include birds, primates and agricultural animals. But some arboviruses can be transmitted to humans with severe negative outcomes. </p>
<p>Five of the most important arboviruses affecting communities in Africa include the chikungunya, dengue, West Nile, yellow fever and Zika viruses. It is <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8055094/">estimated</a> that half of the world’s population is at risk of being infected by an arbovirus.</p>
<p>Some mosquito-borne diseases – but not all – can be fatal to humans. This confirms that every effort must be made to prevent being bitten by a mosquito and infected using both pharmaceutical and non-pharmaceutical measures.</p>
<h2>Chikungunya</h2>
<p>The name chikungunya is derived from the Kimakonde language (used in Tanzania and Mozambique) and means “<a href="https://www.worldmosquitoprogram.org/sites/default/files/2022-04/WMP%20chikungunya%20%281%29.pdf">to become contorted</a>”. The symptoms of chikungunya virus include headaches, a rash, fatigue, fever and muscle and joint pain. Generally these symptoms clear within a week. Occasionally, an infection can result in a severe fever and extremely painful joints, which can last for months or years, inducing a hunched, contorted appearance. Unfortunately, there are no antiviral or vaccine treatments available for chikungunya virus. Deaths from chikungunya are rare and are generally associated with other underlying health problems.</p>
<p>The chikungunya virus was first identified in <a href="https://www.worldmosquitoprogram.org/en/learn/mosquito-borne-diseases/chikungunya">1952</a> during an outbreak in Tanzania. It is transmitted by <em>Aedes aegypti</em> and <em>Aedes albopictus</em> mosquitoes. Over 100 countries across the globe have reported chikungunya virus cases. The risk of outbreaks is extremely high wherever these mosquito species are present around homes and urban areas.</p>
<p>Female <em>Aedes</em> mosquitoes tend to feed just after sunrise and around sunset. They lay eggs that can survive drying out. This makes vector control rather challenging. Current control strategies focus on reducing the number of water containers that these mosquitoes like to breed in, the use of insecticides against adult mosquitoes and personal protection to prevent mosquito bites.</p>
<h2>Dengue</h2>
<p>The World Health Organization has classified <a href="https://www.worldmosquitoprogram.org/sites/default/files/2022-04/WMP%20dengue%20%281%29.pdf">dengue virus</a> as one of the top ten global health threats. It’s one of the fastest spreading mosquito-borne diseases. At least half of the world’s population is at risk of infection. </p>
<p>Like chikungunya virus, dengue is spread by <em>Aedes aegypti</em> and <em>Aedes albopictus</em> mosquitoes. Both viruses share the same control interventions and non-specific symptoms of headaches, a rash, fever and muscle and joint pain, so they are often misdiagnosed. </p>
<p>Most human cases of dengue are asymptomatic or present with mild symptoms, which last for two to seven days. In certain individuals, dengue virus progresses to severe disease and symptoms include persistent vomiting, bleeding gums or nose and enlarged liver. This must be treated as a medical emergency as these complications can be lethal. Dengue virus can be diagnosed using a rapid diagnostic test or a polymerase chain reaction (PCR) test. </p>
<p>But there is no treatment available. A vaccine has been developed and has been approved for use in a few countries – but is not widely available in <a href="https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue">Africa at present</a>. </p>
<h2>Zika</h2>
<p>The Zika virus was identified in humans in the 1950s. But it only became a pathogen of major public concern in 2016 following the <a href="https://www.worldmosquitoprogram.org/en/learn/mosquito-borne-diseases/zika">2015 Zika virus pandemic</a>. The virus is transmitted by <em>Aedes aegypti</em> and <em>Aedes albopictus</em> mosquitoes, and is generally non-lethal in humans. Most people infected with Zika virus do not show any symptoms. A few have non-specific symptoms like fever, rash, headaches, muscle and joint pains and conjunctivitis. These can last two to seven days. </p>
<figure class="align-center ">
<img alt="parent and children working out in swimming pool" src="https://images.theconversation.com/files/479591/original/file-20220817-15-uou8bk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/479591/original/file-20220817-15-uou8bk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/479591/original/file-20220817-15-uou8bk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/479591/original/file-20220817-15-uou8bk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/479591/original/file-20220817-15-uou8bk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/479591/original/file-20220817-15-uou8bk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/479591/original/file-20220817-15-uou8bk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The 2015 Zika outbreak resulted in scores of babies born with microcephaly.</span>
<span class="attribution"><span class="source">Joa Souza/Shutterstock</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>Individuals infected with Zika virus while pregnant are at an <a href="https://www.who.int/news-room/fact-sheets/detail/zika-virus">increased risk</a> of stillbirth, abortion, neurological disorders or delivering children with birth defects, including microcephaly. PCR testing can be used to diagnose Zika virus, but there is no treatment available.</p>
<h2>Yellow fever</h2>
<p><em>Aedes aegypti</em> and <em>Aedes albopictus</em> mosquitoes are also responsible for the transmission of yellow fever, so named because the virus causes jaundice (yellowing of eyes and skin due to impaired liver function).</p>
<p>Symptoms in mild cases <a href="https://www.worldmosquitoprogram.org/en/learn/mosquito-borne-diseases/yellow-fever">include</a> fever, headaches, chills, back pain, fatigue, jaundice, vomiting and bleeding from the mouth, nose, eyes or stomach. These generally clear within five days. Approximately 50% of the small number of patients who develop severe symptoms will die with 10 days of becoming infected. Yellow fever can be diagnosed by PCR or enzyme-linked immunosorbent assay (ELISA). Although there is no treatment for yellow fever, a very effective vaccine is widely available. A single vaccine dose provides <a href="https://www.who.int/news-room/fact-sheets/detail/yellow-fever">lifelong immunity</a>, so all individuals living in or travelling to areas endemic for yellow fever should take the vaccine.</p>
<h2>West Nile</h2>
<p>The West Nile virus was first isolated from a woman in the <a href="https://www.who.int/news-room/fact-sheets/detail/west-nile-virus">West Nile region of Uganda</a>. It is transmitted by mosquitoes belonging the genus <em>Culex</em>. The natural vertebrate hosts are wild birds. But the virus can be transmitted to a number of different animals, including humans, through the bite of an infected mosquito. Approximately 80% of the people infected with West Nile virus will not show any symptoms. Those who do become symptomatic have mild non-specific symptoms that include headaches, fever, tiredness, body aches, nausea, vomiting and, occasionally, a rash. A small proportion of symptomatic patients, however, develop severe disease. This is associated with neurological impairment, and can be fatal in extreme cases. </p>
<p>West Nile virus infection can be diagnosed by PCR or ELISA, with only supportive treatment available for neurological impairment. It has been suggested that people who are older than 50 or immunocompromised are at greater risk of severe infection. An integrated approach comprising water management together with chemical and biological interventions is needed to control the spread of the <em>Culex</em> vectors.</p><img src="https://counter.theconversation.com/content/188856/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jaishree Raman receives funding from the Gates Foundation, the Global Fund, the South African Medical Research Council, the Research Trust, National Research Foundation and the National Institute for Communicable Diseases.</span></em></p><p class="fine-print"><em><span>Shüné Oliver receives funding from the National Research Foundation and the Female Academic Leadership Fellowship. </span></em></p>It is estimated that half of world’s population is at risk of being infected by an arbovirus.Jaishree Raman, Principal Medical Scientist and Head of Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research, National Institute for Communicable DiseasesShüné Oliver, Medical scientist, National Institute for Communicable DiseasesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1858332022-06-30T15:20:20Z2022-06-30T15:20:20ZViruses can change your scent to make you more attractive to mosquitoes, new research in mice finds<figure><img src="https://images.theconversation.com/files/471659/original/file-20220629-13-56a1wn.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2129%2C1402&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mosquito-borne diseases are estimated to cause over 1 million deaths a year.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/biting-mosquito-royalty-free-image/960349766">mrs/Moment via Getty Images</a></span></figcaption></figure><p>Mosquitoes are the <a href="https://www.cdc.gov/globalhealth/stories/2019/world-deadliest-animal.html">world’s deadliest animal</a>. <a href="https://doi.org/10.1016/B978-0-12-812365-2.00003-2">Over 1 million deaths</a> per year are attributed to <a href="https://www.cdc.gov/niosh/topics/outdoor/mosquito-borne/default.html">mosquito-borne diseases</a>, including malaria, yellow fever, dengue fever, Zika and chikungunya fever.</p>
<p>How mosquitoes seek out and feed on their hosts are important factors in how a virus circulates in nature. Mosquitoes spread diseases by acting as carriers of viruses and other pathogens: A mosquito that bites a person infected with a virus can acquire the virus and pass it on to the next person it bites. </p>
<p>For immunologists and infectious disease researchers <a href="https://scholar.google.com/citations?user=6iEQIeIAAAAJ&hl=en">like me</a>, a better understanding of how a virus interacts with a host may offer new strategies for preventing and treating mosquito-borne diseases. In our <a href="https://doi.org/10.1016/j.cell.2022.05.016">recently published study</a>, my colleagues and I found that some viruses can alter a person’s body odor to be more attractive to mosquitoes, leading to more bites that allow a virus to spread. </p>
<h2>Viruses change host odors to attract mosquitoes</h2>
<p>Mosquitoes locate a potential host through <a href="https://doi.org/10.1016/j.cub.2015.07.057">different sensory cues</a>, such as your <a href="https://doi.org/10.7554/eLife.11750">body temperature</a> and the <a href="https://doi.org/10.1017/S0007485300007811">carbon dioxide</a> emitted from your breath. Odors also play a role. Previous lab research has found that mice <a href="https://doi.org/10.1073%2Fpnas.1405617111">infected with malaria</a> have changes in their scents that make them more attractive to mosquitoes. With this in mind, my colleagues and I wondered if other mosquito-borne viruses, such as dengue and Zika, can also change a person’s scent to make them more attractive to mosquitoes, and whether there is a way to prevent these changes.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/j6MrN9o0BfA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A number of factors can make you more attractive to mosquitoes, including the odors you emit.</span></figcaption>
</figure>
<p>To investigate this, we placed mice infected with the dengue or Zika virus, uninfected mice and mosquitoes in one of three arms of a glass chamber. When we applied airflow through the mouse chambers to funnel their odors toward the mosquitoes, we found that more mosquitoes chose to fly toward the infected mice over the uninfected mice.</p>
<p>We ruled out carbon dioxide as a reason for why the mosquitoes were attracted to the infected mice, because while Zika-infected mice emitted less carbon dioxide than uninfected mice, dengue-infected mice did not change emission levels. Likewise, we ruled out body temperature as a potential attractive factor when mosquitoes did not differentiate between mice with elevated or normal body temperatures. </p>
<p>Then we assessed the role of body odors in the mosquitoes’ increased attraction to infected mice. After placing a filter in the glass chambers to prevent mice odors from reaching the mosquitoes, we found that the number of mosquitoes flying toward infected and uninfected mice were comparable. This suggests that there was something about the odors of the infected mice that drew the mosquitoes toward them.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/471703/original/file-20220629-17-7vpcaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Gloved hand holding two test tubes full of mosquitoes in a lab" src="https://images.theconversation.com/files/471703/original/file-20220629-17-7vpcaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471703/original/file-20220629-17-7vpcaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471703/original/file-20220629-17-7vpcaf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471703/original/file-20220629-17-7vpcaf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471703/original/file-20220629-17-7vpcaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471703/original/file-20220629-17-7vpcaf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471703/original/file-20220629-17-7vpcaf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Volunteering in a mosquito study may require a few bites.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/cropped-hand-holding-mosquito-in-test-tube-at-royalty-free-image/1026135942">Panyawat Boontanom/EyeEm via Getty Images</a></span>
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<p>To identify the odor, we isolated 20 different gaseous chemical compounds from the scent emitted by the infected mice. Of these, we found three to stimulate a significant response in mosquito antennae. When we applied these three compounds to the skin of healthy mice and the hands of human volunteers, only one, <a href="https://doi.org/10.1111/eea.12297">acetophenone</a>, attracted more mosquitoes compared to the control. We found that infected mice produced 10 times more acetophenone than uninfected mice. </p>
<p>Similarly, we found that the odors collected from the armpits of dengue fever patients contained more acetophenone than those from healthy people. When we applied the dengue fever patient odors on one hand of a volunteer and a healthy person’s odor on the other hand, mosquitoes were consistently more attracted to the hand with dengue fever odors.</p>
<p>These findings imply that the dengue and Zika viruses are capable of increasing the amount of acetophenone their hosts produce and emit, making them even more attractive to mosquitoes. When uninfected mosquitoes bite these attractive hosts, they may go on to bite other people and spread the virus even further.</p>
<h2>How viruses increase acetophenone production</h2>
<p>Next, we wanted to figure out how viruses were increasing the amount of mosquito-attracting acetophenone their hosts produce. <a href="https://doi.org/10.1111/eea.12297">Acetophenone</a>, along with being a chemical commonly used as a <a href="https://pubchem.ncbi.nlm.nih.gov/compound/Acetophenone">fragrance</a> in perfumes, is also a metabolic byproduct commonly produced by certain bacteria living on the skin and in the intestines of both people and mice. So we wondered if it had something to do with changes in the type of bacteria on the skin.</p>
<p>To test this idea, we removed either the skin or intestinal bacteria from infected mice before exposing them to mosquitoes. While mosquitoes were still more attracted to infected mice with depleted intestinal bacteria compared to uninfected mice, they were significantly less attracted to infected mice with depleted skin bacteria. These results suggest that skin microbes are an essential source of acetophenone. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/471714/original/file-20220629-20-3iu2bq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Long chains of Bacillus megatherium under a microscope" src="https://images.theconversation.com/files/471714/original/file-20220629-20-3iu2bq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471714/original/file-20220629-20-3iu2bq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471714/original/file-20220629-20-3iu2bq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471714/original/file-20220629-20-3iu2bq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471714/original/file-20220629-20-3iu2bq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471714/original/file-20220629-20-3iu2bq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471714/original/file-20220629-20-3iu2bq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Viruses can alter the skin microbiome to increase the presence of bacteria like <em>Bacillus</em>, which produce mosquito-attracting odors.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/aLPmBV">Marc Perkins/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
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<p>When we compared the skin bacteria compositions of infected and uninfected mice, we identified that a common type of rod-shaped bacteria, <a href="https://www.britannica.com/science/bacillus-bacteria"><em>Bacillus</em></a>, was a major acetophenone producer and had significantly increased numbers on infected mice. This meant that the dengue and Zika viruses were able to change their host’s odor by altering the microbiome of the skin.</p>
<h2>Reducing mosquito-attracting odors</h2>
<p>Finally, we wondered if there was a way to prevent this change in odors. </p>
<p>We found one potential option when we observed that infected mice had decreased levels of an important microbe-fighting molecule produced by skin cells, called RELMα. This suggested that the dengue and Zika viruses suppressed production of this molecule, making the mice more vulnerable to infection.</p>
<p><a href="https://doi.org/10.1016/j.chom.2019.04.004">Vitamin A</a> and its related chemical compounds are known to strongly boost production of RELMα. So we fed a vitamin A derivative to infected mice over the course of a few days and measured the amount of RELMα and <em>Bacillus</em> bacteria present on their skin, then exposed them to mosquitoes.</p>
<p>We found that infected mice treated with the vitamin A derivative were able to restore their RELMα levels back to those of uninfected mice, as well as reduce the amount of <em>Bacillus</em> bacteria on their skin. Mosquitoes were also no more attracted to these treated, infected mice than uninfected mice. </p>
<p>Our next step is to replicate these results in people and eventually apply what we learn to patients. <a href="https://www.who.int/data/nutrition/nlis/info/vitamin-a-deficiency">Vitamin A deficiency</a> is common in developing countries. This is especially the case in sub-Saharan Africa and Southeast Asia, where mosquito-transmitted viral diseases are prevalent. Our next steps are to investigate whether dietary vitamin A or its derivatives could reduce mosquito attraction to people infected with Zika and dengue, and subsequently reduce mosquito-borne diseases in the long term.</p><img src="https://counter.theconversation.com/content/185833/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Penghua Wang receives funding from the National Institutes of Health, Department of Health and Human Services, United States organization. He is a regular member of American Association of Immunologists, American Society for Virology, The Society of Chinese Bioscientists in America. </span></em></p>Certain viruses like dengue and Zika can make their hosts smell tastier to mosquitoes. Luckily, vitamin A and its derivatives may help combat these odor changes.Penghua Wang, Assistant Professor of Immunology, University of ConnecticutLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1721452021-12-29T21:26:56Z2021-12-29T21:26:56Z5 things research from twins taught us about health, behaviour and what makes us unique<figure><img src="https://images.theconversation.com/files/436555/original/file-20211209-140109-1g6swwj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/M-adWhDQd7Y">Keisha Montfleury/Unsplash</a></span></figcaption></figure><p>Researchers often compare the differences between identical and fraternal twins to better understand health and behaviour. </p>
<p>The first major insight is that genes and environments almost always combine to influence our life trajectory. Sometimes the largest factor is genetics (think genetic disorders). Sometimes it’s environment (think infections). Mostly, it’s somewhere in between. </p>
<p>Such studies have accelerated the search for genes and environmental agents that cause or trigger diseases. This has helped us understand, treat and even prevent diseases. As twin research has <a href="https://www.twins.org.au/research/tools-and-resources/125-conversation-in-twin-research/377-twin-research-designs-and-analytic-approaches">matured</a>, it has progressed to addressing important questions about when and how diseases originate. </p>
<p>So what has research from twins taught us about specific diseases and the human body?</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/seeing-double-why-twins-are-so-important-for-health-and-medical-research-5273">Seeing double: why twins are so important for health and medical research</a>
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<h2>1. Smoking increases the risk of bone fracture</h2>
<p>Most studies linking environment and disease are complicated by genetic factors. To get around this, we can work with twins who differ in environmental factors. </p>
<p>One such <a href="https://www.nejm.org/doi/full/10.1056/nejm199402103300603">Australian study from 1994</a> compared 20 pairs of female twins in which only one of each pair was a long-term, heavy smoker. </p>
<p>The researchers found smoking one pack of cigarettes a day for 20 years resulted in sufficient loss in bone density to cause osteoporosis. This doubled the risk of having a bone fracture. </p>
<p>This provided compelling evidence that smoking causes osteoporosis and an increased risk of bone fractures.</p>
<h2>2. Events around the time of birth are not a major cause of epilepsy</h2>
<p>Epilepsy is a group of disorders where brain activity is abnormal and seizures are the presenting feature. Traditionally, diagnosis was not possible until after a person’s first seizure, which can occur at any stage of life, from babies to the elderly.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4166361/">Twin studies</a> since the 1960s have shown a mix of genes and environment cause epilepsy. However, until the early 1990s, it was assumed that problems during the birthing process were a major cause of epilepsy.</p>
<figure class="align-center ">
<img alt="Older men stand beside each other, smiling." src="https://images.theconversation.com/files/436563/original/file-20211209-68670-15wadz1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/436563/original/file-20211209-68670-15wadz1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/436563/original/file-20211209-68670-15wadz1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/436563/original/file-20211209-68670-15wadz1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/436563/original/file-20211209-68670-15wadz1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/436563/original/file-20211209-68670-15wadz1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/436563/original/file-20211209-68670-15wadz1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Identical twins share almost all their DNA.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/senior-twin-men-smiling-on-camera-1919843804">Shutterstock</a></span>
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<p>Obstetricians and midwives were often blamed for causing epilepsy. However, a <a href="https://pubmed.ncbi.nlm.nih.gov/8255449/">twin study</a> in 1993 did not support a link between minor problems during birth and the later development of epilepsy. </p>
<p>This information has helped doctors and their patients better understand the causes of epilepsy and not necessarily attribute blame to the birthing process.</p>
<h2>3. Identical twins are different under the skin from before birth</h2>
<p>Genetically identical twins nearly always look identical. Yet, at birth, they have already accumulated differences in the structure and function of their genes. </p>
<p>These <a href="https://press.princeton.edu/books/hardcover/9780691173887/innate">differences</a> are caused by a mix of chance events and individual experiences in the womb.</p>
<p>The location a fertilised egg implants in the womb is random, but some locations are more favourable to growth. For the subset of identical twins who split before they reach the womb, different locations could create different environments in which a baby develops. </p>
<figure class="align-center ">
<img alt="Twin newborn babies sleep, their arms raised." src="https://images.theconversation.com/files/436558/original/file-20211209-142574-qu4qd5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/436558/original/file-20211209-142574-qu4qd5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=305&fit=crop&dpr=1 600w, https://images.theconversation.com/files/436558/original/file-20211209-142574-qu4qd5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=305&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/436558/original/file-20211209-142574-qu4qd5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=305&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/436558/original/file-20211209-142574-qu4qd5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=384&fit=crop&dpr=1 754w, https://images.theconversation.com/files/436558/original/file-20211209-142574-qu4qd5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=384&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/436558/original/file-20211209-142574-qu4qd5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=384&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Identical, but still different.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sleeping-newborn-identical-boy-twins-267663011">Shutterstock</a></span>
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<p>As a result of this or other chance events, around one in six twins differ more than 20% in weight at birth, which may be associated with an increased <a href="https://obgyn.onlinelibrary.wiley.com/doi/10.1111/aogs.13613">risk</a> of illness at birth, especially for the smaller twin. </p>
<p>Such individual experiences could also help explain Brazilian twin pairs in which only one child was born with <a href="https://www.mdpi.com/2414-6366/5/4/188">Zika virus</a> infection.</p>
<h2>4. Leukaemia originates before birth</h2>
<p>Changes in the genetic sequence of blood cells can predispose people to develop leukaemia (cancer of the blood). </p>
<p>Such changes are unique to each person but <em>when</em> these changes happened to people used to be a mystery. That was until identical twin children were <a href="https://www.sciencedirect.com/science/article/pii/S0006497120768072?via%3Dihub">discovered with leukaemias</a> originating from the same cell. </p>
<p>Lymphocytes (white blood cells) of the immune system shuffle their immune genes at random, making each person genetically unique, even identical twins. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/same-same-but-different-when-identical-twins-are-non-identical-112684">Same same but different: when identical twins are non-identical</a>
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<p>The researchers <a href="https://www.sciencedirect.com/science/article/pii/S0006497120768072?via%3Dihub">concluded</a> the leukaemia started in one twin in the womb and spread to the other twin through blood vessels in a shared placenta. </p>
<p>But while the first step towards leukaemia happened before birth, the cancer progression differed among the twins, resulting in leukaemia being diagnosed at different ages.</p>
<p>This provided the first evidence that some leukaemias can lay dormant for years and enabled future research that would pinpoint the events along this process. </p>
<h2>5. Many twins don’t know if they’re identical or fraternal</h2>
<p>Identical twins start as one fertilised egg that splits after a few days. They share almost 100% of their DNA and are almost always the same sex. </p>
<p>Fraternal twins result from two eggs fertilised around the same time. They’re as genetically different as any pair of siblings and can have the same, or different sex. </p>
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<img alt="Twin women hug outside in the sunshine." src="https://images.theconversation.com/files/437106/original/file-20211213-25-1fbing6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/437106/original/file-20211213-25-1fbing6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/437106/original/file-20211213-25-1fbing6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/437106/original/file-20211213-25-1fbing6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/437106/original/file-20211213-25-1fbing6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/437106/original/file-20211213-25-1fbing6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/437106/original/file-20211213-25-1fbing6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Fraternal twins are as genetically different as a pair of siblings.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/portrait-identical-ginger-twin-sisters-smiling-723502963">Shutterstock</a></span>
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</figure>
<p>In 2012, my colleagues and I at <a href="https://www.twins.org.au/">Twins Research Australia</a> conducted a study at a national twins festival on pairs who had any uncertainty about their genetic identity. We used “genetic fingerprinting” on DNA from cheek swabs provided by same-sex twins of all ages. This test is the definitive way of discovering whether twins are identical or fraternal. </p>
<p>We compared this with perceptions of the twins themselves before they took the test. </p>
<p>We <a href="https://www.twins.org.au/research/tools-and-resources/125-conversation-in-twin-research/374-the-importance-of-zygosity-knowledge-for-twins-and-science">found</a> almost one-third of the twins we tested had been either incorrect or unsure about their genetic identity. Some had even been misinformed by medical professionals. </p>
<p>The universal sentiment was twins and their families felt better knowing the truth. Our data enabled us to develop better educational <a href="https://www.twins.org.au/twins-and-families/expecting-twins">resources</a> for twins and their advocates to know more about themselves. </p>
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Read more:
<a href="https://theconversation.com/not-all-twins-are-identical-and-thats-been-an-evolutionary-puzzle-until-now-138209">Not all twins are identical and that's been an evolutionary puzzle, until now</a>
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<img src="https://counter.theconversation.com/content/172145/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jeffrey Craig is Deputy Director of Twins Research Australia and President of the International Society for Twin Studies. He receives funding from the IMPACT Institute, Deakin University, the National Health and Medical Research Council, Australia, and the Waterloo Foundation, UK. He is affiliated with the Gene(e)quality Network. </span></em></p>Genes and environments almost always combine to influence our risk of diseases. Research in twins has helped us understand how.Jeffrey Craig, Professor in Medical Sciences, Deakin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1678332021-09-21T10:44:18Z2021-09-21T10:44:18ZCommon pesticide may have made the Zika epidemic worse – new research<p>Before Covid, there was Zika. In 2015, the number of babies born in Brazil with small heads and brains – a condition known as microcephaly – suddenly increased dramatically. The severe deformities left the children disabled for life, and caused intense global concern.</p>
<p>These cases of microcephaly were soon shown to be caused by pregnant women being <a href="https://www.sciencedirect.com/science/article/pii/S1473309916303188?via%3Dihub">infected with the mosquito-borne Zika virus</a>. The virus infects and kills cells that form the brain, hampering its proper development.</p>
<p>But the impact was not universal – certain regions in north-eastern Brazil saw <a href="https://www.nature.com/articles/nature.2016.20309">far more cases of microcephaly than others</a>.</p>
<p>Scientists began to question whether other factors might be at play that intensified the epidemic in some places. Not long after, they focused their attention on <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5760164/#:%7E:text=Of%20particular%20note%20is%20that,been%20shown%20to%20cause%20microcephaly">pyriproxyfen</a>, a globally approved pesticide used against household insects in agriculture – including mosquitoes. Pyriproxyfen was used intensively in the regions with the highest numbers of microcephaly cases.</p>
<p>Now, in <a href="https://www.sciencedirect.com/science/article/pii/S0269749121012367?via%3Dihub">a new study</a>, we have shown that pyriproxyfen could indeed exacerbate the already severe effects the Zika virus has on foetal brain development.</p>
<h2>Pyriproxyfen and Zika</h2>
<p>In late 2014, pyriproxyfen was introduced to drinking water throughout Brazil to control the <em>Aedes aegypti</em> mosquito population, which spreads the Dengue and Zika viruses.</p>
<p>But the insecticide is known to accumulate in the environment for years, eventually finding its way into the human body. So to prevent potential side-effects, the <a href="https://www.who.int/water_sanitation_health/dwq/chemicals/pyriproxyfenvector.pdf">World Health Organisation</a> had recommended the daily intake of pyriproxyfen should not exceed 0.3 mg/L for an average adult, and concentrations in drinking water should be lower than 0.01 mg/L.</p>
<p>As babies and foetuses generally absorb or accumulate more chemicals than adults, they can be at greater risk. And because there was a strong geographical overlap between the use of pesticides and microcephaly cases, even these small doses raised issues concerning safety.</p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S1473309917307272?via%3Dihub">Epidemiological</a> and <a href="https://link.springer.com/article/10.1007/s11356-020-10517-5">experimental</a> studies have since delivered contradictory results regarding whether or not pyriproxyfen was implicated in the disease outbreak. But in our recently published study, we discovered that pyriproxyfen impairs thyroid hormone signalling in the brain, modifying crucial processes for its proper development.</p>
<h2>How pyriproxyfen affects brain development</h2>
<p>Thyroid hormone is an important molecule that helps shape the foetal brain. Without it, the brain doesn’t grow as it’s supposed to, leaving affected children with learning difficulties for life.</p>
<p>In the lab, we house genetically modified tadpoles that emit green fluorescence when exposed to thyroid hormone. More thyroid hormone means more green signal, indicating the hormone is active in the tadpoles’ cells.</p>
<p>When we exposed our tadpoles to pyriproxyfen, the green signal dropped dramatically. This demonstrated that the pesticide blocks thyroid hormone action.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/414332/original/file-20210803-25-14b0hxc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/414332/original/file-20210803-25-14b0hxc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/414332/original/file-20210803-25-14b0hxc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/414332/original/file-20210803-25-14b0hxc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/414332/original/file-20210803-25-14b0hxc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/414332/original/file-20210803-25-14b0hxc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/414332/original/file-20210803-25-14b0hxc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Genetically modified tadpoles emit green fluorescence when exposed to thyroid hormone (T3 in the image). When they were simultaneously exposed to pyriproxyfen, the fluorescent signal dropped significantly, showing the insecticide blocks thyroid hormone action.</span>
<span class="attribution"><span class="source">Petra Spirhanzlova, MNHN</span></span>
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<p>One of the most important roles of thyroid hormone is to generate a balanced amount of nerve cells and their supporting cells, known as glia. Together, they form the essential building blocks of the brain.</p>
<p>Since pyriproxyfen blocks normal thyroid hormone action, we thought it might affect the generation of neurons and glial cells too. To investigate this, we used stem cells cultured from mouse brains, and exposed them to increasing doses of the pesticide.</p>
<p>The findings were clear: the higher the dose, the fewer cells were generated, and the more they died, producing an unbalanced proportion of nerve cells and glia.</p>
<p>The brains of the exposed tadpoles in our study did not develop normally, and made them behave unnaturally. Underlying these changes were altered expression patterns of a number of genes.</p>
<p>A key player in this was the gene <em>Msi1</em>, which encodes a protein called Musaschi-1. The Zika virus <a href="https://doi.org/10.1126/science.aam9243">uses this protein</a> to replicate and infect other cells, and we knew from <a href="https://www.sciencedirect.com/science/article/pii/S1934590912001737?via%3Dihub">previous studies</a> that more thyroid hormone resulted in less Musaschi-1.</p>
<p>Not surprisingly, the cells that survived pesticide exposure contained much more of the protein due to blocked thyroid hormone action. That’s why we hypothesised that, through increasing Musaschi-1, pyriproxyfen could allow the virus to replicate faster.</p>
<p>To test this, we infected exposed stem cells with the Zika virus and found that the transcription of key genes was altered compared to when they were infected with the virus alone and not exposed to the pesticide. Although we didn’t observe higher infection rates, it’s still possible that pesticide exposure could aggravate hampered brain development. That can worsen the impact the virus has on a child’s later-life intellectual capacities, and requires further investigation.</p>
<h2>Regulating pesticides</h2>
<p>This is not the first time a pesticide has been shown to alter the course of a disease.</p>
<p>For example, individuals with higher amounts of another chemical that disrupts the endocrine system, perfluorobutanoic acid, in their blood, are at risk of a <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0244815">more severe course of Covid-19</a>.</p>
<p>But for many other ubiquitous pesticides to which we are continuously exposed in our daily life, we have no clue as to how they affect us, and whether they interact with viral diseases.</p>
<p>We need better testing protocols for pesticides to obtain more solid data to inform health policies and decision makers.</p>
<p>As for pyriproxyfen, Europe is not proposing to use it at concentrations advised by the World Health Organization, but <a href="http://www.fao.org/faolex/results/details/en/c/LEX-FAOC198465/">recently reauthorised it</a>.</p>
<p>Our study emphasises again how little we know about the harmful effects of pesticides on human health, notably on brain development, but also the natural environment as a whole.</p><img src="https://counter.theconversation.com/content/167833/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Pieter Vancamp has received funding from the Foundation for Medical Research and the European Thyroid Association.</span></em></p><p class="fine-print"><em><span>Barbara Demeneix ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>A new study shows that the pesticide pyriproxyfen – widely used in Brazil during the Zika outbreak of 2015 – could disrupt thyroid hormones and thus affect brain development in children.Pieter Vancamp, Post-doctorant, Muséum national d’histoire naturelle (MNHN)Barbara Demeneix, Professor Physiology, Endocrinology, Muséum national d’histoire naturelle (MNHN)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1616382021-06-03T10:23:11Z2021-06-03T10:23:11ZThe ocean economy is booming: who is making money, who is paying the price? Podcast<p>In this week’s episode of <a href="https://theconversation.com/uk/topics/the-conversation-weekly-98901">The Conversation Weekly</a>, we ask a question – who is trying to make money from our oceans and is it sustainable? Also, why Brazilian women who lived through Zika are avoiding getting pregnant during the COVID-19 pandemic. </p>
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<p>From deep-sea mining, to fishing, to oil and gas exploration, the ocean economy is booming. This is one of the themes that’s emerged from a series The Conversation has been running over the past few months called <a href="https://theconversation.com/uk/topics/oceans-21-96784">Oceans 21</a>, examining the history and future of the world’s oceans. </p>
<p>A key question here is what the economic exploitation of our oceans is doing to the ocean environment. It’s important to balance economic growth with preservation of ocean habitats. But researchers – and to some extent, governments – are increasingly focusing on a third consideration: the people who’ve depended on the ocean for generations. In this episode, we speak to three experts about the tension between economic growth, environmental protection and the people that rely on oceans – and what’s being done to make the exploitation of the oceans more sustainable. </p>
<p>Jean-Baptiste Jouffray, post-doctoral researcher at the Stockholm Resilience Centre at Stockholm University, Sweden, has come up with a new term to describe what’s been happening to the oceans over the past two decades: <a href="https://www.sciencedirect.com/science/article/pii/S2590332219302751">the blue acceleration</a>. “Humanity has used the ocean for millennia as a source of food, as a means of transportation,” he says, but today’s use of the ocean is “unprecedented” for its diversity and intensity. </p>
<p>One of the prospects for further development that’s exciting some is mining the floor of the ocean for minerals including manganese, nickel and cobalt. There’s a lot of this activity in the middle of the Pacific, where mining companies are working on ways to collect potato-sized nodules rich in these precious metals. </p>
<p>But Anna Metaxas, professor of oceanography at Dalhousie University in Nova Scotia, Canada, says lots of unique animals including deep water corals and sponges live no where else on earth except on and around these rocks and the sediment they sit on top of. This sediment stores a lot of the carbon that gets absorbed by the ocean and if you disturb it – through mining, for example – “all of a sudden you’re affecting how much carbon has been sequestered, how much carbon is sitting within that sediment.”</p>
<p>Meanwhile, the effects of ocean exploitation on coastal communities in west Africa can be devastating. Ifesinachi Okafor-Yarwood, lecturer in sustainable development at St Andrew’s University in Scotland, tells us that fisher communities are being left deeply vulnerable. Some of those whose livelihoods have been destroyed by pollution or over-fishing, or who have been displaced by large development projects, are left with few options but to turn to piracy or other illegal activities. “This is unfortunately the cyclical relationship between the pressure on marine resources, primarily fisheries, and how it is affecting the people,” she tells us. </p>
<p>In our second story this week, we’re heading to Brazil, which remains a global epicentre of the coronavirus pandemic – just a few years after another devastating epidemic, Zika. </p>
<p>Zika, you may remember, caused some children whose mothers were infected during pregnancy to be born with microcephaly, or abnormally small heads. Our colleague Catesby Holmes, international editor at The Conversation US, wondered how Brazilian women who’d already lived through Zika were feeling about another novel disease outbreak, COVID-19. </p>
<p>She spoke with Letícia Marteleto, professor of sociology at the University of Texas at Austin College of Liberal Arts, about <a href="https://theconversation.com/scarred-by-zika-and-fearing-new-covid-19-variants-brazilian-women-say-no-to-another-pandemic-pregnancy-158366">her research project</a> in Pernambuco, Brazil - an epicenter of Zika that’s also been hit hard by the coronavirus. Marteleto and her team have been surveying women in the area about their attitudes toward having children. They found that Zika left an emotional scar on women. Many plan to avoid getting pregnant during this pandemic – even though the coronavirus does not appear to cause birth defects. </p>
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Read more:
<a href="https://theconversation.com/scarred-by-zika-and-fearing-new-covid-19-variants-brazilian-women-say-no-to-another-pandemic-pregnancy-158366">Scarred by Zika and fearing new COVID-19 variants, Brazilian women say no to another pandemic pregnancy</a>
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<p>And Françoise Marmouyet, membership editor for The Conversation in Paris, tells us about a new podcast series about the state of democracy in France, the US and China. </p>
<p>The Conversation Weekly is produced by Mend Mariwany and Gemma Ware, with sound design by Eloise Stevens. Our theme music is by Neeta Sarl. You can find us on Twitter <a href="https://twitter.com/TC_Audio">@TC_Audio</a>, on Instagram at <a href="https://www.instagram.com/theconversationdotcom/?hl=en">theconversationdotcom</a>. or via email on podcast@theconversation.com. You can also sign up to <a href="https://theconversation.com/newsletter?utm_campaign=PodcastTCWeekly&utm_content=newsletter&utm_source=podcast">The Conversation’s free daily email here</a>.</p>
<p>A transcript of this episode will be available soon. </p>
<p>News clips in this episode are from <a href="https://www.youtube.com/watch?v=0uRkmtC36tY">CBS</a> <a href="https://www.youtube.com/watch?v=rYRreX3aIrw">News</a> and <a href="https://www.youtube.com/watch?v=Jgw8kw6caR4">UOL</a>.</p>
<p><em>You can listen to The Conversation Weekly via any of the apps listed above, our <a href="https://feeds.acast.com/public/shows/60087127b9687759d637bade">RSS feed</a>, or find out how else to <a href="https://theconversation.com/how-to-listen-to-the-conversations-podcasts-154131">listen here</a>.</em></p>
<p><em>This story was updated to more accurately reflect that seafloor sediments store carbon.</em></p><img src="https://counter.theconversation.com/content/161638/count.gif" alt="The Conversation" width="1" height="1" />
Plus, why Brazilian women who lived through Zika are avoiding getting pregnant during the COVID-19 pandemic. Listen to episode 18 of The Conversation Weekly podcast.Gemma Ware, Head of AudioCatesby Holmes, International Editor | Politics Editor, The Conversation USDaniel Merino, Associate Breaking News Editor and Co-Host of The Conversation Weekly PodcastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1583662021-04-28T12:15:37Z2021-04-28T12:15:37ZScarred by Zika and fearing new COVID-19 variants, Brazilian women say no to another pandemic pregnancy<figure><img src="https://images.theconversation.com/files/396852/original/file-20210423-21-1mpg3z0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A field hospital in São Paulo state, Brazil, on March 26, 2021. Brazil keeps setting new COVID-19 records, with up to 4,000 people dying daily. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/patients-affected-by-the-covid-19-coronavirus-remain-at-a-news-photo/1231952275?adppopup=true">Miguel Schincariol/AFP via Getty Images</a></span></figcaption></figure><p>“We have to avoid a pregnancy,” said Rosa, about the possibility of getting pregnant during the COVID-19 pandemic. “My feeling is that I don’t want to have a baby. What I went through in 2017 when I had Raíssa, God forbid.”</p>
<p>Rosa lives in the Brazilian state of Pernambuco. Her first child, Raíssa, was born during the <a href="https://www.cdc.gov/zika/index.html">epidemic of Zika</a> – a mosquito-borne disease that caused severe birth defects if contracted during pregnancy, among other effects. </p>
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<p>Between 2015 and 2017, some 3,700 babies in Brazil <a href="https://www.npr.org/sections/goatsandsoda/2019/10/09/768629177/zika-researchers-are-learning-more-about-the-long-term-consequences-for-children">were born with a Zika-related congenital malformation</a> of abnormally small heads. These babies are now 4 to 7 years old. Some <a href="https://www.newscientist.com/article/2208677-half-of-babies-affected-by-zika-virus-are-developing-normally-by-age-2/">began to develop normally within a few years</a>. But others face <a href="https://www.hrw.org/news/2019/05/08/brazils-zika-babies-are-growing">enormous difficulties eating, walking, speaking and seeing</a>. They require highly specialized care, and families get meager governmental assistance.</p>
<p>Pernambuco was one of the epicenters of Brazil’s Zika outbreak. Today, Brazil is an epicenter of the coronavirus pandemic, with more than 13 million confirmed COVID-19 cases, nearly <a href="https://www.worldometers.info/coronavirus/country/brazil/">400,000 deaths</a> and no end in sight.</p>
<p>Meanwhile, Zika is still circulating – though it’s much less common.</p>
<p>For Rosa and many other women in Pernambuco, the thought of navigating another pregnancy during another novel infectious disease outbreak is incredibly stressful – and their anxiety is starting to show in Brazil’s declining pregnancy intentions and births.</p>
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<a href="https://images.theconversation.com/files/396851/original/file-20210423-23-1a41nwo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Man spoon feeds his toddler child, lying in a baby seat" src="https://images.theconversation.com/files/396851/original/file-20210423-23-1a41nwo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/396851/original/file-20210423-23-1a41nwo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/396851/original/file-20210423-23-1a41nwo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/396851/original/file-20210423-23-1a41nwo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/396851/original/file-20210423-23-1a41nwo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/396851/original/file-20210423-23-1a41nwo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/396851/original/file-20210423-23-1a41nwo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Some children with microcephaly have difficulty swallowing.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/brazilian-wallace-da-silva-cruz-feeds-his-two-year-old-son-news-photo/1071527866?adppopup=true">Mauro Pimintel/AFP via Getty Images</a></span>
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<h2>The Zika-COVID connection</h2>
<p>I lead the <a href="https://liberalarts.utexas.edu/zika/">DeCodE Project</a>, a study funded by the National Institute of Child Health and Human Development. The project aims to understand whether and how women of reproductive age change their childbearing attitudes, desires and behaviors during novel infectious disease crises like Zika and COVID-19.</p>
<p>COVID-19 and Zika are distinct viruses with different modes of transmission and health effects. Neither had ever been seen before in Brazil. The novelty of such diseases generates extreme uncertainty over infection risks and a chaotic prevention response, especially for typically high-risk groups like <a href="https://utswmed.org/medblog/pregnancy-anxiety-covid19-pandemic/">pregnant people and their babies</a>.</p>
<p>Our study group conducted interviews throughout 2020 with 3,998 women ages 18 to 34 in Pernambuco. We have been monitoring them with periodic surveys since then. These women are navigating back-to-back novel infectious disease outbreaks that overlap substantially with their reproductive years.</p>
<p>Early on in the Zika crisis, it was unclear whether a fetus in utero could get the virus. Later, fetal transmission was confirmed – along with <a href="https://www.nejm.org/doi/full/10.1056/NEJMsr1604338">the risk of severe fetal abnormalities at birth</a>.</p>
<p>Now, just a few years later, COVID-19 is bringing similar uncertainty. </p>
<p>The <a href="https://covid.cdc.gov/covid-data-tracker/#pregnant-birth-infant">specific risk of COVID-19 to pregnant people</a> and their infants is <a href="https://wwwnc.cdc.gov/eid/article/27/2/20-3824_article">not yet entirely clear</a>. Early in the pandemic, evidence suggested that pregnancy posed <a href="https://theconversation.com/pregnant-in-a-time-of-coronavirus-the-changing-risks-and-what-you-need-to-know-134745">no greater risk in terms of catching COVID-19</a> or suffering worse symptoms than the general population. </p>
<p>In June 2020, however, the U.S. Centers for Disease Control and Prevention added pregnancy to the list of health conditions that make COVID-19 patients more likely to be <a href="https://www.cdc.gov/media/releases/2020/p0625-update-expands-covid-19.html">hospitalized and admitted to the intensive care unit</a>, based on <a href="https://theconversation.com/coronavirus-pregnant-women-and-infants-new-research-136639">several studies</a>. There is also evidence of increased stillbirths and preterm deliveries during the pandemic, though it is not entirely clear whether these increases result from SARS-CoV-2 infection or indirect effects such as <a href="https://doi.org/10.1001/jama.2020.12746">stress or reluctance to seek medical care</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/396848/original/file-20210423-13-hiex5d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Older woman pours water on a younger woman wearing a face mask and bikini with a very big baby belly" src="https://images.theconversation.com/files/396848/original/file-20210423-13-hiex5d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/396848/original/file-20210423-13-hiex5d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/396848/original/file-20210423-13-hiex5d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/396848/original/file-20210423-13-hiex5d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/396848/original/file-20210423-13-hiex5d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/396848/original/file-20210423-13-hiex5d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/396848/original/file-20210423-13-hiex5d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A midwife from Brazil’s Kumaruara tribe in July 2020 bathes her pregnant daughter with medicinal herbs meant to strengthen her for the pandemic-time delivery.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/midwife-paje-suzete-from-the-kumaruara-tribe-bathes-her-news-photo/1226933180?adppopup=true">Tarso Sarraf/AFP via Getty Images</a></span>
</figcaption>
</figure>
<h2>Race, class and health inequities</h2>
<p>In Brazil, where out-of-control infections have given rise to a more transmissible and deadly variant, pregnant and post-partum women are showing <a href="https://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-38292021000100253">higher death rates from COVID-19</a>. Hospitals are attributing an unusually large number of newborn deaths to COVID-19. On April 17, 2021, <a href="https://www.cnn.com/2021/04/17/americas/brazil-pregnancy-covid-intl/index.html">Brazilian officials</a> took the unusual step of asking women to avoid getting pregnant. </p>
<p>Not all people, of course, have total control over their bodies – no matter how anxious they are about a potential pandemic pregnancy. In Brazil, high-quality health care and contraceptive options are less accessible to poorer women and <a href="http://authors.elsevier.com/sd/article/S0277953617304410">Black women</a> than they are to white women and wealthy women.</p>
<p>During the coronavirus pandemic, for example, Black women from lower socioeconomic backgrounds have seen their medical care severely interrupted. <a href="https://sites.utexas.edu/decodificando/files/2021/01/1-s2.0-S0305750X20304320-main.pdf">Our data shows</a> that 58% were unable to find health services of any kind when they needed them. In contrast, 23% of wealthier white women experienced a similar neglect.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/396842/original/file-20210423-23-1p9uq86.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Health worker in full-body PPE walks a pregnant woman down a hall" src="https://images.theconversation.com/files/396842/original/file-20210423-23-1p9uq86.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/396842/original/file-20210423-23-1p9uq86.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/396842/original/file-20210423-23-1p9uq86.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/396842/original/file-20210423-23-1p9uq86.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/396842/original/file-20210423-23-1p9uq86.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/396842/original/file-20210423-23-1p9uq86.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/396842/original/file-20210423-23-1p9uq86.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A health worker assists a pregnant COVID-19 patient in Pará State, Brazil, in July 2020.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/worker-from-the-special-secretariat-for-indigenous-health-news-photo/1227679511?adppopup=true">Tarso Sarraf/AFP via Getty Images</a></span>
</figcaption>
</figure>
<p>And in a <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/padr.12074">2017 study I led</a> during the Zika epidemic, wealthier women in Brazil reported having more autonomy over their reproductive decisions than those of lower socioeconomic backgrounds.</p>
<p>Still, Brazilian women did their best to avoid childbearing during Zika. <a href="https://link.springer.com/article/10.1007/s13524-020-00871-x">One of our studies</a> shows temporary birth declines of 10% nationally and of 28% in Pernambuco in November 2016, roughly a year after the link between Zika and birth malformations was established.</p>
<p>It appears that women are now doing the same during COVID-19. </p>
<p>Half of the women we interviewed who want children said they intend to avoid pregnancy during the pandemic. Women who had Zika or were close to people who did are 11% more likely to say this, <a href="https://liberalarts.utexas.edu/zika/news/decode-project-pre-print-scars-from-a-previous-epidemic-among-white-and-black-women-social-proximity-to-zika-and-fertility-intentions-during-the-covid-19">according to one preliminary study conducted by my team</a>.</p>
<p>“I am really afraid of getting pregnant,” said Sônia, a 24-year-old woman in Recife, the capital city of Pernambuco state, in an interview in May 2020. “It is the same feeling” as during Zika “but now it is a little worse.”</p>
<p><a href="https://datastudio.google.com/u/0/reporting/1f9481ef-3e60-4f2d-a871-0e4d739a4163/page/h1XEC?s=teTj3FWK8yQ">Our analysis of preliminary data</a> from Brazil’s civil registry bears this out: Live births in January 2021 – roughly nine months after Brazil’s first confirmed case of COVID-19 – dropped 12% compared to last year. This information may change, however, as data is updated and government demographic data becomes available. Brazil’s 2020 census <a href="https://www.dw.com/pt-br/governo-confirma-cancelamento-do-censo-em-2021/a-57319018">was canceled</a>.</p>
<p>Our research illustrates how the effects of epidemics go beyond just mortality and health. For some Brazilian women of childbearing age, it changes their desire to become parents.</p>
<p>[<em>Over 104,000 readers rely on The Conversation’s newsletter to understand the world.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=100Ksignup">Sign up today</a>.]</p><img src="https://counter.theconversation.com/content/158366/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Letícia Marteleto receives funding from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, one of the National Institutes of Health in the U.S. Department of Health and Human Services. </span></em></p>Officials in Brazil recently asked women to avoid pregnancy, citing heightened risk to them and newborns. But births were already dropping; a new study attributes it to the trauma of Zika.Letícia Marteleto, Professor of Sociology, The University of Texas at AustinLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1274152020-07-14T12:35:46Z2020-07-14T12:35:46ZAn argument for gene drive technology to genetically control populations of insects like mosquitoes and locusts<figure><img src="https://images.theconversation.com/files/346100/original/file-20200707-18-ar8drt.jpg?ixlib=rb-1.1.0&rect=18%2C6%2C4047%2C2600&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Swarms of locusts are seen on a tree in a residential area in the southwestern Pakistan city of Quetta on June 12, 2020. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/swarms-of-locusts-are-seen-on-a-tree-in-a-residential-area-news-photo/1219574634?adppopup=true">BANARAS KHAN/AFP via Getty Images</a></span></figcaption></figure><p>The fate of society rests in part on how humans navigate their complicated relationship with insects – trying to save “good” insects and control “bad” ones. Some insects, like mosquitoes, bite people and make them sick – remember <a href="https://theconversation.com/zika-virus-mosquitoes-and-travel-patterns-will-determine-spread-of-virus-53484">Zika</a>? Now the U.S. mosquito season is already in full swing, with <a href="https://www.cbsnews.com/news/dengue-fever-florida-keys-11th-case/">over 10 cases of Dengue fever</a> reported in the Florida Keys this year. Some insects, like <a href="https://theconversation.com/beyond-honey-bees-wild-bees-are-also-key-pollinators-and-some-species-are-disappearing-89214">bees, are pollinators</a> that help produce our food. Others, like <a href="https://theconversation.com/locust-invasions-are-cyclical-african-states-shouldnt-be-caught-napping-130883">locusts, currently threaten crops</a> <a href="https://www.reuters.com/article/us-kenya-locusts-apps/kenya-uses-app-in-battle-against-desert-locusts-idUSKBN2471I9">in East Africa</a> and <a href="https://www.hindustantimes.com/india-news/armed-with-pesticides-mi-17-choppers-fight-locust-swarms/story-sYKhnBtek5gKdSlSIkUdUP.html">Asia</a>, preferring to eat our food instead. </p>
<p>Insects have proven themselves extremely capable at evolving strategies to get around control methods, such as chemical insecticides and habitat modification, and current pest control technologies are simply not keeping up.</p>
<p><a href="https://scholar.google.com/citations?user=FKhYoSAAAAAJ&hl=en">We are</a> <a href="https://scholar.google.com/citations?user=tzo9De0AAAAJ&hl=en">both</a> insect scientists. Our research has included <a href="https://www.bbc.com/news/health-48464510">engineering a fungus to control malaria mosquitoes</a>, <a href="https://theconversation.com/queen-bees-put-their-workers-on-the-pill-to-stop-them-reproducing-50316">uncovering the reproductive biology of honey bee workers</a> and understanding the <a href="https://doi.org/10.1111/mve.12441">health impacts of invasive ticks</a>. We’ve come to appreciate the potential of emerging technologies like gene drive. This technology can guarantee that a trait will be inherited by the next generation. Such traits include making mosquitoes <a href="https://www.wired.com/story/heres-the-plan-to-end-malaria-with-crispr-edited-mosquitoes/">immune to the malaria parasite</a> so they cannot spread the disease to humans. </p>
<p>Recently we contributed to a <a href="https://www.entsoc.org/sites/default/files/files/Science-Policy/2019/ESA-Position-Statement-on-the-Importance-of-Genetic-Research.pdf">statement that advocates for continuing gene drive research</a>. In light of <a href="https://www.nature.com/articles/d41586-018-07600-w">calls for a moratorium</a>, this statement recognizes that a ban on gene drive research would hamper a better understanding, and thus mitigation, of risks associated with this technology. </p>
<p>Moratoriums on gene drive technology have been called for and rejected <a href="https://www.nature.com/news/gene-drive-moratorium-shot-down-at-un-biodiversity-meeting-1.21216">at the last two</a> United Nations Conventions on Biological Diversity. But there is <a href="https://www.euractiv.com/section/health-consumers/news/ngos-call-for-moratorium-on-controversial-gene-drive-organisms/">a new push for a moratorium</a>.</p>
<h2>What is gene drive?</h2>
<p>Gene drive is a technology that could allow society to control insects in a more targeted manner.</p>
<p>The general underlying principle of all gene drives is an organism that will produce offspring similar to themselves.</p>
<p>Some characteristics are randomly passed on from parents to the next generation. However, gene drive forces a different type of inheritance that ensures a specific characteristic is always present in the next generation. Scientists engineer gene drive using various molecular tools.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/305061/original/file-20191203-66986-50cruy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/305061/original/file-20191203-66986-50cruy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/305061/original/file-20191203-66986-50cruy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/305061/original/file-20191203-66986-50cruy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/305061/original/file-20191203-66986-50cruy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/305061/original/file-20191203-66986-50cruy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=583&fit=crop&dpr=1 754w, https://images.theconversation.com/files/305061/original/file-20191203-66986-50cruy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=583&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/305061/original/file-20191203-66986-50cruy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=583&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In insects with a gene drive, a trait is passed to almost all progeny.</span>
<span class="attribution"><span class="source">Entomological Society of America</span></span>
</figcaption>
</figure>
<p>Gene drive is not just a human invention; some occur naturally in insects. For example, in <a href="https://blogs.ucl.ac.uk/gee-research/2014/06/12/meiotic-drive-sexual-selection/">stalk-eyed flies</a>, a gene on a sex-related chromosome causes any male fly to die without a certain gene “cargo,” including a gene that results in longer eyestalks. This type of genetic phenomenon has been well studied by scientists.</p>
<p>To date, gene drive has been discussed in the media primarily <a href="https://www.nytimes.com/2020/01/08/magazine/gene-drive-mosquitoes.html">in order to eradicate malaria</a>. This may give you the impression that gene drive can be used only <a href="https://www.statnews.com/2018/09/24/gene-drive-lab-mosquitos/">to drive mosquitoes to extinction</a>. However, gene drive technologies are highly versatile and can be designed to bring about different outcomes. They can also be applied in most insect species that scientists can study in the laboratory.</p>
<h2>Why insects?</h2>
<p>Insects reproduce quickly and produce lots of offspring, which makes them obvious candidates for a technology that relies on inheritance like gene drive. This is why insects are at the leading edge of gene drive research. Gene drive is a new technology that could provide a solution to a variety of insect issues society faces today.</p>
<p>For instance, a gene drive has been <a href="https://doi.org/10.1073/pnas.1713139115">developed to stop a major crop pest, the spotted-wing <em>Drosophila</em></a>. Insecticide sensitivity could be spread through populations of this pest species to stop <a href="https://www.usda.gov/media/blog/2019/08/27/want-save-money-invest-agricultural-biosecurity">tens of millions of dollars in crop damage every year</a> in the United States.</p>
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<p>Gene drive could also be a more targeted approach to stopping invasive insects, such as the infamous <a href="https://www.aphis.usda.gov/aphis/resources/pests-diseases/hungry-pests/the-threat/imported-fire-ant/imported-fire-ant">fire ant</a>, from destroying native ecosystems. In the United States, millions of dollars have been spent on <a href="https://sfyl.ifas.ufl.edu/lawn-and-garden/sustainable-fire-ant-control/">removing fire ants using techniques including chemical insecticides</a>, but if these persistent ants are not completely eradicated, they invade again.</p>
<p>Aside from how good insects are at circumventing our strategies to control them, another major struggle for controlling insects is finding them. Insects have evolved to quickly find the opposite sex to mate, and gene drives, which are passed on by mating, can take advantage of this fact of insect life. This also means this technology targets only the intended species, which is not the case for chemical insecticides currently in use.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/311954/original/file-20200127-81336-1gv6znp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311954/original/file-20200127-81336-1gv6znp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=355&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311954/original/file-20200127-81336-1gv6znp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=355&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311954/original/file-20200127-81336-1gv6znp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=355&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311954/original/file-20200127-81336-1gv6znp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=446&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311954/original/file-20200127-81336-1gv6znp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=446&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311954/original/file-20200127-81336-1gv6znp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=446&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The first gene drive in insects were developed by nature: for example, in stalk-eyed flies.</span>
<span class="attribution"><span class="source">Gbohne/WikimediaCommons</span></span>
</figcaption>
</figure>
<p>Insect scientists, inspired by natural examples of gene drive, have wanted to design gene drive in insects for decades. Only recently have new molecular tools, such as the gene editing tool <a href="https://theconversation.com/what-is-crispr-gene-editing-and-how-does-it-work-84591">CRISPR-Cas</a>, made the gene drive dream a reality. For now, gene drive insects <a href="https://www.npr.org/sections/goatsandsoda/2019/02/20/693735499/scientists-release-controversial-genetically-modified-mosquitoes-in-high-securit">live in laboratories and none has been released into the wild</a>. Still, a lot can be learned about how gene drive works while it is safely contained in a laboratory.</p>
<h2>Criticisms of gene drive</h2>
<p>Using gene drive is not a universally popular idea. Criticisms tend to fall into three categories: ethical concerns, mistrust of technology and unintended ecological consequences.</p>
<p>Ethical concerns about gene drive are often motivated by larger issues, such as how to stop gene drive from being used in biological weapons by engineering insects that are more dangerous. Then there is the question of who should decide which gene drive projects move forward and what types of insects with gene drive can be released into the environment. These questions can’t be answered by scientists alone.</p>
<p><a href="https://www.washingtonpost.com/news/innovations/wp/2016/07/21/humans-once-opposed-coffee-and-refrigeration-heres-why-we-often-hate-new-stuff/">Societal mistrust of technology</a> is a hurdle that some powerful, innovative technologies must overcome for public acceptance. The issue of technological mistrust often stems from disagreements about who should be developing technology to control insects and for what purposes.</p>
<p>The third common argument against gene drive technologies is that they might cause unintended consequences in the ecosystem because gene drive is designed by humans and unnatural. What will happen to the natural ecosystem if a population, even of mosquitoes that make people sick, is driven to extinction? Will this cause threats to natural biodiversity and the security of food? These questions are ultimately asking the consequences of intervening in the natural order of the world. But who defines what is the natural state of an ecosystem? <a href="https://theconversation.com/were-kidding-ourselves-if-we-think-we-can-reset-earths-damaged-ecosystems-59972">Ecosystems are already constantly in flux</a>.</p>
<h2>Preparing for a future that may include gene drive insects</h2>
<p>When a gene drive is developed, it is tailored to the needs of a particular situation. This means the <a href="https://www.ncbi.nlm.nih.gov/books/NBK379271/">anticipated risks</a> posed by each gene drive are project-specific and should be considered and regulated on a case-by-case basis. A responsible way to protect society from these risks is to advocate for continued research that enables scientists to describe and find solutions to them. Beyond the science, regulatory and accountability systems are needed so that regulations are adhered to and public safety is protected. </p>
<p>Researchers are also still exploring the science underlying the gene drive. Can gene drive be designed to be reversible or more efficient? Can the effect of a gene drive on an ecosystem be predicted? Such important unanswered questions are why even the most ardent supporters of this technology say more research is needed. Society needs new tools to control insect pests and protect ecosystems, and gene drive promises to augment our toolbox.</p><img src="https://counter.theconversation.com/content/127415/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Isobel Ronai received funding from the International Union of Biochemistry and Molecular Biology, and the Australian Federal Government. </span></em></p><p class="fine-print"><em><span>Brian Lovett receives funding from the National Institutes of Health National Institute of Allergy and Infectious Diseases. </span></em></p>Gene drive guarantees that a trait will be passed to the next generation. But should society use this tool to control insect populations?Isobel Ronai, Postdoctoral Research Fellow, University of SydneyBrian Lovett, Postdoctoral Researcher in Mycology, West Virginia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1397102020-06-03T12:16:09Z2020-06-03T12:16:09ZGenetically modified mosquitoes could be released in Florida and Texas beginning this summer – silver bullet or jumping the gun?<figure><img src="https://images.theconversation.com/files/338916/original/file-20200601-95032-uv3cee.jpg?ixlib=rb-1.1.0&rect=18%2C37%2C4078%2C2480&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In 2018 scientists of the Miami-Dade County Mosquito Control tested a new way to suppress mosquito populations carrying the Zika virus. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/dr-bill-petrie-director-of-miami-dade-county-mosquito-news-photo/916186362?adppopup=true">RHONA WISE/AFP via Getty Images</a></span></figcaption></figure><p>This summer, for the first time, genetically modified mosquitoes could be released in the U.S. </p>
<p>On May 1, 2020, the company Oxitec received an <a href="https://content.govdelivery.com/accounts/USAEPAOPPT/bulletins/2896a76">experimental use permit</a> from the U.S. Environmental Protection Agency to release <a href="https://beta.regulations.gov/document/EPA-HQ-OPP-2019-0274-0353">millions of GM mosquitoes</a> (labeled by Oxitec as OX5034) every week over the next two years in Florida and Texas. Females of this mosquito species, <em>Aedes aegypti</em>, transmit dengue, chikungunya, yellow fever and Zika viruses. When these lab-bred GM males are released and mate with wild females, their female offspring die. Continual, large-scale releases of these OX5034 GM males should eventually cause the temporary collapse of a wild population. </p>
<p>However, as vector biologists, geneticists, policy experts and bioethicists, we are concerned that current government oversight and scientific evaluation of GM mosquitoes do not ensure their responsible deployment. </p>
<h2>Genetic engineering for disease control</h2>
<p>Coral reefs that can withstand rising sea temperatures, <a href="https://theconversation.com/new-genetically-engineered-american-chestnut-will-help-restore-the-decimated-iconic-tree-52191">American chestnut trees</a> that can survive blight and <a href="https://doi.org/10.1016/j.pt.2018.02.003">mosquitoes that can’t spread disease</a> are examples of how genetic engineering may transform the natural world. </p>
<p>Genetic engineering offers an unprecedented opportunity for humans to reshape the fundamental structure of the biological world. Yet, as new advances in <a href="https://doi.org/10.1038/s41586-018-0692-z">genetic decoding</a> and <a href="https://doi.org/10.1073/pnas.1805874115">gene editing</a> emerge with speed and enthusiasm, the ecological systems they could alter remain enormously complex and understudied. </p>
<p>Recently, no group of organisms has received more attention for genetic modification than mosquitoes – to <a href="https://dx.doi.org/10.1371%2Fjournal.pntd.0003864">yield inviable offspring</a> or make them <a href="https://doi.org/10.1371/journal.ppat.1002458">unsuitable for disease transmission</a>. These strategies hold considerable potential benefits for the hundreds of millions of people impacted by <a href="https://www.who.int/neglected_diseases/vector_ecology/mosquito-borne-diseases/en/">mosquito-borne diseases</a> each year. </p>
<p>Although the EPA approved the permit for Oxitec, state approval is still required. A previously planned release in the Florida Keys of an earlier version of Oxitec’s GM mosquito (OX513) was <a href="https://www.wlrn.org/post/gmo-mosquito-application-withdrawn-another-way#stream/0">withdrawn in 2018</a> after <a href="https://www.wlrn.org/post/gmo-mosquito-application-withdrawn-another-way#stream/0">a referendum in 2016</a> indicated significant opposition from local residents. Oxitec has field-trialed their GM mosquitoes in <a href="https://doi.org/10.1080/23299460.2017.1326257">Brazil</a>, the Cayman Islands, Malaysia and Panama. </p>
<p>The <a href="https://beta.regulations.gov/document/EPA-HQ-OPP-2019-0274-0355">public forum</a> on Oxitec’s recent permit application garnered 31,174 comments opposing release and 56 in support. The EPA considered these during their review process. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/338910/original/file-20200601-95036-uhkqxr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/338910/original/file-20200601-95036-uhkqxr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/338910/original/file-20200601-95036-uhkqxr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/338910/original/file-20200601-95036-uhkqxr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/338910/original/file-20200601-95036-uhkqxr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/338910/original/file-20200601-95036-uhkqxr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/338910/original/file-20200601-95036-uhkqxr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/338910/original/file-20200601-95036-uhkqxr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In 2016, technicians from the Oxitec laboratory located in Campinas, Brazil, released genetically modified mosquitoes <em>Aedes egypti</em> to combat the Zika virus.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/biologist-works-with-genetically-modified-mosquitoes-on-news-photo/509588568?adppopup=true">Victor Moriyama / Getty Images</a></span>
</figcaption>
</figure>
<h2>Time to reassess risk assessment?</h2>
<p>However, it is difficult to <a href="https://beta.regulations.gov/document/EPA-HQ-OPP-2019-0274-0359">assess how EPA regulators</a> weighed and considered public comments and how much of the <a href="https://doi.org/10.1093/biosci/biz009">evidence used in final risk determinations</a> was provided solely by the technology developers. </p>
<p>The closed nature of this risk assessment process is concerning to us. </p>
<p>There is a potential bias and conflict of interest when experimental trials and assessments of ecological risk lack <a href="https://doi.org/10.1080/23299460.2017.1326257">political accountability</a> and are performed by, or in close collaboration with, the technology developers. </p>
<p>This scenario becomes more troubling with a <a href="https://www.biospace.com/article/releases/intrexon-scores-oxitec-in-160-million-stock-cash-deal-/">for-profit technology company</a> when cost- and risk-benefit analyses comparing GM mosquitoes to other approaches <a href="https://www.regulations.gov/docket?D=EPA-HQ-OPP-2019-0274">aren’t being conducted</a>. </p>
<p>Another concern is that <a href="https://apps.who.int/iris/handle/10665/271990">risk assessments</a> tend to focus on only a narrow set of biological parameters – such as the potential for the GM mosquito to transmit disease or the potential of the mosquitoes’ new proteins to trigger an allergic response in people – and neglect other important <a href="https://www.econexus.info/publication/release-gm-mosquito-aedes-aegypti-ox513a">biological</a>, <a href="https://dx.doi.org/10.1371%2Fjournal.pntd.0006501">ethical</a> and <a href="https://doi.org/10.1080/00139157.2017.1350011">social</a> considerations. </p>
<p>To address these shortcomings, the Institute for Sustainability, Energy and Environment at University of Illinois Urbana-Champaign convened a “<a href="https://sustainability.illinois.edu/outreach/critical-conversations/critical-conversation-spring-2019/">Critical Conversation</a>” on GM mosquitoes. The discussion involved 35 participants from academic, government and nonprofit organizations from around the world with expertise in mosquito biology, community engagement and risk assessment. </p>
<p>A primary takeaway from this conversation was an urgent need to make regulatory procedures more transparent, comprehensive and protected from biases and conflicts of interest. In short, we believe it is time to reassess risk assessment for GM mosquitoes. Here are some of the key elements we recommend.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/338919/original/file-20200601-95024-hn134f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/338919/original/file-20200601-95024-hn134f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/338919/original/file-20200601-95024-hn134f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/338919/original/file-20200601-95024-hn134f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/338919/original/file-20200601-95024-hn134f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/338919/original/file-20200601-95024-hn134f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/338919/original/file-20200601-95024-hn134f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/338919/original/file-20200601-95024-hn134f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The mosquito spray OFF! was handed out for free at the Zika Virus Town Hall Meeting at Waverly Condominiums in 2016.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/woman-looking-at-the-free-mosquito-spray-off-being-given-news-photo/917609734?adppopup=true">Jeffrey Greenberg/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<h2>Steps to make risk assessment more open and comprehensive</h2>
<p>First, an official, government-funded registry for GM organisms specifically designed to reproduce in the wild and intended for release in the U.S. would make risk assessments more transparent and accountable. Similar to the U.S. <a href="https://clinicaltrials.gov/">database that lists all human clinical trials</a>, this field trial registry would require all technology developers to disclose intentions to release, information on their GM strategy, scale and location of release and intentions for data collection.</p>
<p>This registry could be presented in a way that protects intellectual property rights, just as therapies entering clinical trials are patent-protected in their registry. The GM organism registry would be updated in real time and made fully available to the public. </p>
<p>Second, a broader set of risks needs to be assessed and an evidence base needs to be generated by third-party researchers. Because each GM mosquito is released into a unique environment, risk assessments and experiments prior to and during trial releases should address local effects on the ecosystem and food webs. They should also probe the disease transmission potential of the mosquito’s wild counterparts and <a href="https://doi.org/10.1560/IJEE.56.3-4.353">ecological competitors</a>, examine evolutionary pressures on disease agents in the mosquito community and <a href="https://doi.org/10.1126/science.aaz5392">track the gene flow</a> between GM and wild mosquitoes. </p>
<p>To identify and assess risks, a commitment of funding is necessary. The U.S. <a href="https://www.epa.gov/research-grants/assessment-tools-biotechnology-products">EPA’s recent announcement</a> that it would improve general risk assessment analysis for biotechnology products is a good start. But regulatory and funding support for an external advisory committee to review assessments for GM organisms released in the wild is also needed; <a href="https://doi.org/10.1126/science.aat4612">diverse expertise and local community representation</a> would secure a more fair and comprehensive assessment. </p>
<p>Furthermore, independent researchers and advisers could help guide what data are collected during trials to reduce uncertainty and inform future large-scale releases and risk assessments.</p>
<p>The objective to reduce or even eliminate mosquito-borne disease is laudable. GM mosquitoes could prove to be an important tool in alleviating global health burdens. However, to ensure their success, we believe that regulatory frameworks for open, comprehensive and participatory decision-making are urgently needed. </p>
<p><em>This article was updated to correct the date that Oxitec withdrew its OX513 trial application to 2018.</em></p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p><img src="https://counter.theconversation.com/content/139710/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brian Allan receives funding from the Institute for Sustainability, Energy and Environment. </span></em></p><p class="fine-print"><em><span>Jennifer Kuzma receives funding from the U.S. Department of Agriculture, Walton Family Foundation and National Science Foundation.. </span></em></p><p class="fine-print"><em><span>Natalie Kofler receives funding from the University of Illinois Institute for Sustainability, Energy and the Environment. She is an advisor for the Scientific Citizenship Initiative at Harvard Medical School and founder of Editing Nature. </span></em></p><p class="fine-print"><em><span>Chris Stone and Holly Tuten do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Release of GM mosquitoes in Florida is imminent. But a multidisciplinary team of scientists believe that more studies are needed first. They encourage a publicly accessible registry for GM organisms.Brian Allan, Associate Professor of Entomology, University of Illinois at Urbana-ChampaignChris Stone, Medical Entomologist, University of Illinois at Urbana-ChampaignHolly Tuten, Vector Ecologist, University of Illinois at Urbana-ChampaignJennifer Kuzma, Goodnight-NCGSK Distinguished Professor, North Carolina State UniversityNatalie Kofler, Scientific Citizenship Initiative Advisor and Center for Bioethics Lecturer, Harvard UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1364472020-04-29T17:03:48Z2020-04-29T17:03:48ZCovid-19 or the pandemic of mistreated biodiversity<p>The whole world has been affected by the Covid-19 pandemic – we all fear for our own health, that of our loved ones and also those who are most vulnerable. In the span of just a few weeks, Covid-19 suddenly become more urgent than the crises of ongoing climate change or the dangerous decline in biodiversity. Catastrophic events that once monopolised world attention, such as the <a href="https://theconversation.com/us/topics/bushfires-1377">forest fires in Australia</a>, suddenly seemed less serious than a pandemic that could touch all of us, immediately, in our own homes. </p>
<p>However, like other major epidemics (AIDS, Ebola, SARS, etc.), the emergence of the coronavirus is not unrelated to the climate and biodiversity crises we are experiencing. What do these pandemics tell us about the state of biodiversity?</p>
<h2>New pathogens</h2>
<p>Humankind is destroying natural environments at an accelerating rate. Between 1980 and 2000, more than 100 million hectares of tropical forest were felled, and more than 85% of wetlands have been destroyed since the start of the industrial era. In so doing, we put human populations, often in precarious health, in contact with new pathogens. The disease reservoirs are wild animals usually restricted to environments in which humans are almost entirely absent or who live in small, isolated populations. </p>
<p>Due to the destruction of the forests, the villagers settled on the edge of deforested zones hunt wild animals and send infected meat to cities – this is how <a href="https://www.bbc.com/news/world-africa-31985826">Ebola</a> found its way to major human centres. So-called bushmeat is even exported to other countries to meet the demand of expatriates and thus spreads the health risk far from remote areas.</p>
<p>We shamelessly hunt exotic and wild species for purely recreational reasons – the <a href="https://royalsocietypublishing.org/doi/full/10.1098/rspb.2008.1475">appeal of rare species</a>, exotic meals, naive pharmacopeia, etc. The trade in rare animals feeds the markets and in turn leads to the contamination of urban centres by new maladies. The epidemic of severe acute respiratory syndrome (SARS) rose out of the proximity between bats, carnivores and gullible human consumers. In 2007, a <a href="https://cmr.asm.org/content/20/4/660">major scientific article</a> stated:</p>
<blockquote>
<p>“The presence of a large reservoir of SARS-CoV–like viruses in horseshoe bats, together with the culture of eating exotic mammals in southern China, is a time bomb.” </p>
</blockquote>
<p>This time bomb seems to have exploded in November 2019 with the Covid-19.</p>
<h2>The danger of zoonoses</h2>
<p>The consumption and import/export of exotic animals have two major consequences. First, they increase the risk of an epidemic by putting us in contact with rare infectious agents. While they’re often specialized by species and thus cannot defeat our immune system or even penetrate and use our cells, trafficking and confinement of diverse wild animals together allows infectious agents to recombine and cross the barrier between species. This was the case for SARS and <a href="https://theconversation.com/coronavirus-origins-genome-analysis-suggests-two-viruses-may-have-combined-134059">may have been the case for Covid-19</a>. Beyond the current crisis, this risk is not marginal: It should be remembered that more than two-thirds of emerging diseases are <a href="https://www.nature.com/articles/nature06536">zoonoses</a>, infectious agents that can pass between animals and humans. Of these, the majority comes from wild animals.</p>
<p>Second, capturing and selling exotic animals puts enormous pressure on wild populations. This is the case with the <a href="https://theconversation.com/pangolin-illegal-medicine-trade-threatens-these-scaly-mammals-with-extinction-33817">pangolin</a>, recently brought to light by the Covid-19 pandemic. The eight species of this mammal, which is found in Africa and Asia, are poached for their meat and scales despite their protected status. More than 20 tonnes of meat are seized each year by customs, leading to an estimate of around 200,000 individuals killed each year for this traffic. </p>
<p>Humanity is thus doubly endangering itself: We are enabling the creation of emerging diseases and also destroying the fragile biodiversity that provides <a href="https://www.who.int/globalchange/ecosystems/en/">natural services from which we benefit</a>. </p>
<p>The circumstances of the emergence of these new diseases can be even more complex. This is how Zika and dengue viruses are transmitted by <a href="https://www.who.int/neglected_diseases/vector_ecology/mosquito-borne-diseases/en/">exotic mosquitoes</a> transported by humans through international trade. The trade in used tires in which water collects and allows aquatic mosquito larvae to develop and be transported is particularly criticized. Here the disease does not spread by a first direct contact between the human species and reservoir animals followed by intra-human transmission, but it is transmitted to the human species by vector mosquitoes, the latter moving efficiently with our help.</p>
<h2>Managing human and environmental health</h2>
<p>The World Health Organization’s <a href="https://www.who.int/features/qa/one-health/en/">“One Health” initiative</a> advocates managing the issue of human health in relation to the environment and biodiversity. It has three main objectives: combating zoonoses, ensuring food safety and fighting antibiotic resistance.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/330990/original/file-20200428-110742-mcjx5n.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/330990/original/file-20200428-110742-mcjx5n.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/330990/original/file-20200428-110742-mcjx5n.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=574&fit=crop&dpr=1 600w, https://images.theconversation.com/files/330990/original/file-20200428-110742-mcjx5n.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=574&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/330990/original/file-20200428-110742-mcjx5n.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=574&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/330990/original/file-20200428-110742-mcjx5n.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=721&fit=crop&dpr=1 754w, https://images.theconversation.com/files/330990/original/file-20200428-110742-mcjx5n.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=721&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/330990/original/file-20200428-110742-mcjx5n.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=721&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The ‘One Health’ initiative seeks to promote optimal health for people, animals and the environment.</span>
<span class="attribution"><span class="source">Wikipedia</span></span>
</figcaption>
</figure>
<p>This initiative reminds us that we cannot live in an artificial cocoon, never be in contact with biodiversity whether it be wild, raised or grown. Two of the initiative’s three targets – food security and zoonoses – are directly related to the current Covid-19 crisis. We should not create dangerously unsustainable food circuits, whether it be importing exotic species or feeding unnatural products to farm animals – this was what led to <a href="https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopathy">mad cow disease</a>, after all.</p>
<p>The causes of the biodiversity crisis are well known and so are the remedies. First and foremost is stopping the destruction of the environment – deforestation, the world trade in any commodity or living species, the transport of exotic animals – for short-term gain, often just a few percentage points of profitability compared to local production.</p>
<h2>The world after Covid-19</h2>
<p>Voices are starting to be heard that that the <a href="https://www.theguardian.com/world/2020/mar/28/after-the-coronavirus-australia-and-the-world-can-never-be-the-same-again">“world will not be the same after Covid-19”</a>. So let’s integrate into this “next world” a greater respect for biodiversity. It’s our greatest immediate benefit!</p>
<p>The world that we will leave to our children and grandchildren will experience <a href="https://www.theguardian.com/global-development/2019/sep/18/a-deadly-virus-could-kill-80-million-people-in-hours-experts-warn">deadly new pandemics</a>, that is unfortunately certain. How many will there be depends on our efforts to preserve biodiversity and natural balances, everywhere on the planet. Beyond the current human tragedies, one can at least hope that Covid-19 has had the positive effect of raising this awareness.</p>
<hr>
<p><em>This article is published in collaboration with researchers from the ISYEB (Institute for Systematics, Evolution, Biodiversity of the National Museum of Natural History, Sorbonne Université).</em></p><img src="https://counter.theconversation.com/content/136447/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Les auteurs ne travaillent pas, ne conseillent pas, ne possèdent pas de parts, ne reçoivent pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'ont déclaré aucune autre affiliation que leur organisme de recherche.</span></em></p>Covid-19, like other major epidemics, is not unrelated to the biodiversity and climate crisis we are experiencing.Philippe Grandcolas, Directeur de recherche CNRS, systématicien, ISYEB - Directeur de l'Institut de Systématique, Evolution, Biodiversité (CNRS, SU, EPHE, UA), Muséum national d’histoire naturelle (MNHN)Jean-Lou Justine, Professeur, UMR ISYEB (Institut de Systématique, Évolution, Biodiversité), Muséum national d’histoire naturelle (MNHN)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1320512020-02-20T12:19:04Z2020-02-20T12:19:04ZCoronavirus: We need to start preparing for the next viral outbreak now<figure><img src="https://images.theconversation.com/files/316252/original/file-20200219-10985-wiikfe.jpg?ixlib=rb-1.1.0&rect=17%2C211%2C5868%2C3706&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Residents of Hong Kong wear masks as they make their commutes. </span> <span class="attribution"><span class="source">AP Photo/Kin Cheung</span></span></figcaption></figure><p>The coronavirus outbreak is officially a crisis – let’s not waste it.</p>
<p>Undeniably, the international community is taking the matter very seriously, as it should given that the death total from the COVID-19 epidemic <a href="https://www.nytimes.com/2020/02/09/world/asia/coronavirus-china.html">already well surpasses that from SARS</a> in the early 2000s.</p>
<p>The World Health Organization <a href="https://www.who.int/news-room/detail/30-01-2020-statement-on-the-second-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-outbreak-of-novel-coronavirus-(2019-ncov)">declared</a> the outbreak a public health emergency of international concern, researchers across the globe <a href="https://www.aljazeera.com/news/2020/02/researchers-ramp-efforts-develop-coronavirus-vaccine-200206120657215.html">are furiously working</a> on <a href="https://www.cnbc.com/2020/02/03/coronavirus-uk-pledges-26-million-for-vaccine-development.html">vaccines</a> against COVID-19, and governments including the U.S. and U.K. <a href="https://www.ft.com/content/5b6b6130-e8d1-3601-8fd1-48b758635735">have allocated</a> more funds to <a href="https://ec.europa.eu/info/news/coronavirus-eu-mobilises-eur10-million-for-research-2020-jan-31_en">boost research and development</a>. </p>
<p>However, even if the international response to COVID-19 has been relatively strong, it may rightfully be considered too little too late, with the epidemic already underway. That’s a mistake we shouldn’t repeat.</p>
<p>As global health researchers, <a href="https://doi.org/10.1016/j.vaccine.2016.12.001">we study</a> the full societal value of vaccination and other interventions to combat infectious disease. Given the <a href="https://www.imf.org/external/pubs/ft/fandd/2018/06/economic-risks-and-impacts-of-epidemics/bloom.htm">tremendous costs</a> associated with epidemics, it’s vital that we begin working to prevent the next outbreak, even as the world struggles to fight COVID-19.</p>
<h2>A predictable scenario</h2>
<p>What’s remarkable about the current situation is its predictability.</p>
<p><a href="https://www.cnbc.com/2020/02/11/coronavirus-likely-jumped-from-bats-to-another-host-before-infecting-humans-who.html">It was predictable</a> that the outbreak would emanate from <a href="https://theconversation.com/a-clue-to-stopping-coronavirus-knowing-how-viruses-adapt-from-animals-to-humans-130790">contact between humans and animals</a> – and that bats may have been involved. It was predictable that its epicenter would be in a densely populated urban area and that it spread rapidly via international air travel. </p>
<p>And it was even predictable that an unknown pathogen would be just as likely to spring an epidemic as a known one. </p>
<p>As was the case with <a href="https://www.nejm.org/doi/10.1056/NEJMoa030747?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3D">SARS</a> and <a href="https://www.who.int/emergencies/zika-virus/articles/one-year-outbreak/en">Zika</a>, the pathogen responsible for the current epidemic <a href="https://www.nature.com/articles/s41586-020-2012-7">was not on anyone’s radar</a> before it began wreaking havoc in China and beyond. </p>
<p>It was also predictable that a rapidly progressing epidemic <a href="https://www.aljazeera.com/news/2020/01/chaos-coronavirus-exposes-china-healthcare-weaknesses-200129050408104.html">would have significant and wide-ranging</a> health, <a href="https://nymag.com/intelligencer/2020/01/why-stock-market-worried-coronavirus.html">economic</a> and social impacts. </p>
<p>Less than two months into the epidemic, China’s health system <a href="https://www.nytimes.com/2020/01/27/world/asia/27china-coronavirus-health.html">has already experienced major strain</a>, with Wuhan in particular struggling to provide quality care to coronavirus patients. In addition, this may be crowding out treatment of other conditions. </p>
<p>The <a href="https://www.washingtonpost.com/business/economy/economic-fallout-from-chinas-coronavirus-mounts-across-the-globe/2020/02/13/7bb69a12-4e8c-11ea-9b5c-eac5b16dafaa_story.html">economic impacts</a> include major disruptions to manufacturing, supply chains, <a href="https://www.forbes.com/sites/kenrapoza/2020/02/14/heres-how-big-a-deal-the-coronavirus-is-to-china-retail-including-apple-sales">retail sales</a>, <a href="https://www.businessinsider.com/coronavirus-impact-america-travel-industry-airlines-economy-2020-2">international travel</a> and <a href="https://www.washingtonpost.com/world/asia_pacific/in-china-200-million-kids-have-gone-back-to-school-online/2020/02/17/e5cc6f10-5131-11ea-80ce-37a8d4266c09_story.html">education</a>.</p>
<p>And the resulting political and social challenges continue to pile up, such as <a href="https://www.nytimes.com/2020/02/15/business/china-coronavirus-lockdown.html">mass quarantines</a>, <a href="https://www.reuters.com/article/us-china-health-usa-discrimination/fake-flyers-and-face-mask-fear-california-fights-coronavirus-discrimination-idUSKBN208063">discrimination</a>, the spread of <a href="https://www.nytimes.com/2020/02/06/health/coronavirus-misinformation-social-media.html">misinformation</a>, <a href="https://www.theguardian.com/science/2020/jan/24/coronavirus-shakes-citizens-faith-in-chinese-government">mistrust in government</a> and <a href="https://www.washingtonpost.com/world/2020/02/18/how-coronavirus-is-worsening-us-china-tensions">extra strain</a> on already tense international relations.</p>
<p>The total costs of this epidemic <a href="https://www.cnbc.com/2020/01/31/coronavirus-just-starting-to-have-an-impact-on-global-economy-geopolitics.html">are already significant</a> and <a href="https://www.cnn.com/2020/02/08/business/coronavirus-global-economy/index.html">could get much worse</a>.</p>
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<img alt="" src="https://images.theconversation.com/files/316256/original/file-20200219-11023-4fay4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316256/original/file-20200219-11023-4fay4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316256/original/file-20200219-11023-4fay4l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316256/original/file-20200219-11023-4fay4l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316256/original/file-20200219-11023-4fay4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316256/original/file-20200219-11023-4fay4l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316256/original/file-20200219-11023-4fay4l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Efforts to contain COVID-19 have shut down much of the Chinese economy and kept workers home during rush hour in Beijing.</span>
<span class="attribution"><span class="source">AP Photo/Andy Wong</span></span>
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<h2>The inevitability of epidemics</h2>
<p>The predictability of the current situation reflects the inevitability of outbreaks and epidemics. </p>
<p>We may not be able to say with certainty where and when they will occur – or what the causative pathogen will be – but we know that another is always lurking. There are also many reasons to believe that their frequency will increase. </p>
<p>Even as global population growth slows, <a href="https://www.imf.org/external/pubs/ft/fandd/2016/03/bloom.htm">it continues apace</a> in the world’s most economically and politically fragile regions. Increasing urbanization is leading to the proliferation of large, dense population centers that act like giant petri dishes for infectious diseases. And population aging <a href="https://www.nature.com/articles/s41514-017-0020-0">is increasing the share of people</a> who are more susceptible to infection and disease. </p>
<p>The geographic ranges of some pathogens and important disease carriers like mosquitoes <a href="https://doi.org/10.1016/S1473-3099(17)30645-X">are expanding due to climate change</a>. And <a href="https://www.who.int/zoonoses/en">humans keep encroaching</a> on animal habitats, increasing the likelihood of cross-species spillovers.</p>
<p>International travel continues to become more common, and globalization ensures that the economic effects of an outbreak anywhere will ripple across distant reaches of humanity.</p>
<h2>Preparing for the worst</h2>
<p>Given all of the costs of epidemics – and all the factors favoring their repeated occurrence – stable and large-scale investments in organizations and activities dedicated to outbreak preparedness, prevention, mitigation and response are likely to pay tremendous dividends.</p>
<p>The <a href="https://cepi.net">Coalition for Epidemic Preparedness Innovations</a>, an alliance to finance and coordinate the development of new vaccines, certainly merits substantial funding, as does <a href="https://www.doi.org/10.1056/NEJMp1613577">development of vaccine platforms generally</a>. Likewise, <a href="https://www.who.int/blueprint/about/en/">greater funding</a> for <a href="https://www.who.int/news-room/detail/27-02-2017-who-publishes-list-of-bacteria-for-which-new-antibiotics-are-urgently-needed">novel antimicrobial treatments</a> and improved diagnostics is desperately needed. <a href="https://globalhealth.harvard.edu/files/hghi/files/global_monitoring_report.pdf">Increased pathogen surveillance</a> in both humans and animals is another urgent priority. </p>
<p>Perhaps what is lacking more than funding, though, is a sufficient level of coordination among the many players in the loose network of international and country-level organizations responsible for controlling and responding to infectious disease outbreaks. The <a href="https://doi.org/10.3389/fimmu.2019.00549">fragmented nature of the global health system</a> creates the possibility for considerable research and functional gaps as well as wasteful duplications of effort.</p>
<p><a href="https://doi.org/10.3389/fimmu.2019.00549">We’ve argued before</a> for the establishment of a global technical council on infectious disease threats to improve collaboration and coordination across organizations, carry out needed research and make high-level, evidence-based recommendations for managing global risks. Such a council would be composed of experts from a wide range of disciplines – including epidemiology, vaccinology, public policy and economics – and could either be affiliated with the WHO or stand alone. </p>
<p>The bottom line is that more and sustained resources are sorely needed to prevent, or at least mitigate, the next outbreak and its impact – whether caused by another coronavirus, a hemorrhagic fever like Ebola, pandemic influenza or a pathogen not yet discovered.</p>
<p>Taking these measures may be expensive, but it will be more costly to sit on our hands. The next outbreak assuredly lies just around the bend.</p>
<p>[<em>Get the best of The Conversation, every weekend.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybest">Sign up for our weekly newsletter</a>.]</p><img src="https://counter.theconversation.com/content/132051/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David E. Bloom receives funding from the National Institute of Aging, the Bill & Melinda Gates Foundation, UNFPA, the Wellcome Trust, Pfizer, GSK, Sanofi, Merck, and Carnegie Corporation of New York. </span></em></p><p class="fine-print"><em><span>Daniel Cadarette receives funding from the Bill & Melinda Gates Foundation and the International Vaccine Institute.</span></em></p>The tremendous costs of COVID-19 show why the world needs to do a better job preventing epidemics from occurring – or at least mitigate the impact.David E. Bloom, Professor of Economics and Demography, Harvard UniversityDaniel Cadarette, Research Assistant, Harvard UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1309502020-01-31T20:18:25Z2020-01-31T20:18:25ZWhat the coronavirus emergency declaration means for Canada<figure><img src="https://images.theconversation.com/files/313136/original/file-20200131-41476-1jtrzdm.jpg?ixlib=rb-1.1.0&rect=86%2C80%2C3416%2C2279&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">People wait at Toronto Pearson International Airport on Jan. 25, 2020. </span> <span class="attribution"><span class="source">THE CANADIAN PRESS/Nathan Denette</span></span></figcaption></figure><p>The director general of the World Health Organization (WHO) has <a href="https://www.who.int/news-room/detail/30-01-2020-statement-on-the-second-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-outbreak-of-novel-coronavirus-(2019-ncov)">decided the outbreak of 2019-nCoV constitutes a public health emergency of international concern (PHEIC)</a> as more countries reported confirmed cases of the coronavirus. The move updates the organization’s decisions from last week, when it said it lacked enough scientific evidence to declare the emergency.</p>
<p>The WHO has declared only five other PHEICs in the past decade: the H1N1 influenza pandemic (2009-10), setbacks in fighting polio (2014), West Africa’s Ebola outbreak (2014), Zika virus (2015-2016) and the recent and ongoing Ebola outbreak in the Democratic Republic of the Congo. </p>
<p>Although the WHO responded to <a href="https://www.who.int/news-room/photo-story/photo-story-detail/urgent-health-challenges-for-the-next-decade">58 health emergencies in 50 countries last year</a>, PHEICs are a unique category of emergencies: they are defined under the <a href="https://www.who.int/ihr/publications/9789241596664/en/">International Health Regulations</a> as extraordinary public health events that endanger global public health through the international spread of disease, and that potentially require a coordinated international response.</p>
<p>There have been three confirmed cases of 2019-nCoV Ontario, and one in British Columbia. Public health officials continue to stress that the risk of infection in Canada is low. So what does the emergency declaration mean for Canadians and Canada’s role internationally?</p>
<h2>Enhanced actions</h2>
<p>The International Health Regulations aim to “prevent, protect against, control and provide a public health response to the international spread of disease in ways that are commensurate with and restricted to public health risks, and which avoid unnecessary interference with international traffic and trade.” </p>
<p>The PHEIC declaration gives the WHO more power to muster an international response to the outbreak to prevent or reduce the spread of disease. Its recommendations are not binding on member countries, but they are expected to follow them. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1222973217435987970"}"></div></p>
<p>In this case, <a href="https://www.who.int/news-room/detail/30-01-2020-statement-on-the-second-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-outbreak-of-novel-coronavirus-(2019-ncov)">the WHO recommendations ask China</a> to enhance its actions to contain the outbreak, share relevant data on cases and conduct exit screening at international airports and ports. It also recommends other countries share information with the WHO, focus on reducing human infections and inform the WHO of any travel restrictions. </p>
<p>The WHO has recommended nations support those with weaker health systems and accelerate the development of vaccines and treatments. Canadian scientists are already working to develop a new vaccine against the novel virus, although it <a href="https://globalnews.ca/news/6481486/canada-vaccine-theresa-tam-coronavirus/">likely won’t be ready for at least a year</a>.</p>
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Read more:
<a href="https://theconversation.com/how-social-media-is-changing-research-and-reactions-to-coronavirus-outbreak-130748">How social media is changing research and reactions to coronavirus outbreak</a>
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<p>The IHR Emergencies Committee, which advises the WHO director general, said the recommendations should be interpreted in the spirit of solidarity and in support of China, to enhance preparedness in other regions of the world that may need additional support. </p>
<p>The committee has warned against any travel or trade restrictions, even as the United States has placed <a href="https://www.cnn.com/2020/01/30/politics/coronavirus-alert/index.html">travel restrictions</a> on travel to China. Canada <a href="https://doi.org/10.1017/cyl.2017.18">closed its borders to people from Ebola-affected countries during the 2014-16 outbreak</a> even though there was no scientific evidence supporting the decision, and was was criticized by the WHO for doing so. </p>
<h2>Why now?</h2>
<p>The declaration of a global public health emergency can have serious repercussions. If it is called too early, it can interfere with international traffic and trade. But if it is called too late, the WHO may be viewed as failing to adequately protect the public’s health. </p>
<p>The WHO has been <a href="https://www.sfchronicle.com/news/article/World-health-agency-opts-against-global-alarm-on-14998851.php">criticized in the past for both premature</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803810/">delayed declarations of PHEICs</a>. Some experts have said <a href="https://www.nytimes.com/2020/01/30/health/coronavirus-world-health-organization.html">WHO was too slow</a> in its declaration on 2019-nCoV.</p>
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Read more:
<a href="https://theconversation.com/coronavirus-in-wuhan-residents-shout-stay-strong-from-windows-130851">Coronavirus in Wuhan: Residents shout 'stay strong' from windows</a>
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<p>The declaration is both a <a href="https://www.washingtonpost.com/politics/2020/01/26/who-held-off-declaring-wuhan-coronavirus-global-health-emergency-heres-why/">political</a> and ethical decision made in a time of immense uncertainty. It must strike a careful balance between the need to curb the spread of disease and prevent unnecessary fear and interference. </p>
<h2>What does it mean?</h2>
<p>It does not necessarily mean the risk of infection has increased in Canada. </p>
<p>The WHO declared the emergency to coordinate an international response to protect countries with health-care systems that are otherwise ill-prepared to deal with this novel virus. </p>
<p>Despite its weaknesses, the Canadian health-care system is relatively well-equipped and prepared to address infectious disease outbreaks, particularly as a result of <a href="https://www.ncbi.nlm.nih.gov/books/NBK92467/">its experience</a> with the outbreak of Severe Acute Respiratory Syndrome (SARS). Multiple systems exist in Canada <a href="https://news.gov.bc.ca/releases/2020HLTH0015-000151">to prevent the spread of serious infectious diseases</a>.</p>
<p>Canadians should not fear 2019-nCoV simply as a result of the WHO’s declaration. Rather Canada and Canadians have an important, collective role to play in curbing the spread of this novel virus — and avoid the mistakes made in the past.</p>
<p>Instead, Canada can offer scientific expertise to help ill-equipped countries with surveillance and detection, and Canadians can do their part to help curb the spread of the disease by adopting common sense hygiene practices.</p><img src="https://counter.theconversation.com/content/130950/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Maxwell J. Smith consults with the World Health Organization.</span></em></p><p class="fine-print"><em><span>Jacob Shelley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The declaration does not mean the risk to Canadians has changed, but it does mean Canada must step up to help those countries with weaker heath-care systems.Maxwell J. Smith, Assistant Professor & Co-Director, Health Ethics, Law, & Policy (HELP) Lab, Western UniversityJacob Shelley, Assistant Professor & Co-Director, Health Ethics, Law, & Policy (HELP) Lab, Western UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1284662019-12-10T19:02:56Z2019-12-10T19:02:56ZAs heat strikes, here’s one way to help fight disease-carrying and nuisance mosquitoes<figure><img src="https://images.theconversation.com/files/305857/original/file-20191209-90588-z0hh9p.jpg?ixlib=rb-1.1.0&rect=10%2C5%2C3446%2C2308&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Although yellow fever does not currently exist in Australia, the species Aedes aegypti - which can transmit the disease - is found widely across northern Queensland. The virus remains a global health concern, but citizen scientists could help prevent its spread.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/dfataustralianaid/10703811283/in/photolist-hiRQbp-o2C5Ea-5teKrM-prufsH-9JrLwy-pQqpF-nL5DfG-77JZRZ-cpUoNL-9tkBLk-5jxMyp-7iZSB-r9ZY2X-cg2SEh-5teJBV-cpUp4u-5pBMJ8-5pBMJp-rrmyFd-5pBMJ4-4XfWfe-b29TGT-Bm2uxJ-a4SkT1-edLmUv-3WkCVT-8uLqtp-c21i5A-emM5p-6qrVrt-NrjrV-xc69Yg-8uPuEu-8uLqBa-a5XbDu-87nf2R-nEXatf-CHguk-nVU9DN-aq412c-fH3CgY-xtKBz-g4wDM-d8VGcm-9AVAYW-foZPD-fnviLL-wgXh5-bvXznE-Xm4f">Simon Kutcher/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Mosquito-borne disease is a concern for health authorities around Australia. Each year, thousands fall ill to <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1005070">Ross River virus disease</a> caused by mosquito bites.</p>
<p>Tracking mosquito populations can help us respond to these threats, and new research suggests citizen scientists may be the key to doing this more effectively.</p>
<p>Health authorities coordinate the surveillance of <a href="https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-018-2901-x?optIn=false">mosquitoes and their pathogens</a>. These surveillance data help improve the understanding of mosquito-borne disease outbreaks.</p>
<p>They also help guide <a href="https://ww2.health.wa.gov.au/Articles/F_I/Fight-the-Bite-campaign">public education campaigns</a>, and assist in mosquito control efforts, <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1440-6055.2008.00642.x">often through the application of insecticides</a>. </p>
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Read more:
<a href="https://theconversation.com/the-worst-year-for-mosquitoes-ever-heres-how-we-find-out-68433">The worst year for mosquitoes ever? Here's how we find out</a>
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<p>However, there aren’t enough resources to set mosquito traps everywhere. It can also be tricky getting specimens from the field to the lab for testing. This is where <a href="https://theconversation.com/explainer-what-is-citizen-science-16487">citizen science</a> is important.</p>
<p>This public-led movement involves volunteers gathering scientific data for programs coordinated by professional scientists, simply through <a href="https://www.environment.nsw.gov.au/research-and-publications/your-research/citizen-science/digital-projects/coastsnap">taking photos</a> or <a href="https://www.frogid.net.au/">recording sounds</a> on their smartphones.</p>
<p>In this way, sightings of <a href="https://www.theguardian.com/environment/2018/aug/06/the-golden-age-of-citizen-science-and-how-it-is-reshaping-the-world">animals and plants</a> can be reported. Citizen scientists can even help in experimental design, data analysis and distribution of research results.</p>
<h2>Getting bu-zzzz-y tracking mosquitoes</h2>
<p>One program called <a href="https://hehp.wordpress.com/category/mozzie-monitors/">Mozzie Monitors</a>, <a href="https://www.unisa.edu.au/sansominstitute/mosquito/">launched in June</a> last year, is shedding light on how citizen science can address critical resource shortages in mosquito surveillance efforts. </p>
<p>Our research published last week in <a href="https://www.sciencedirect.com/science/article/pii/S0048969719353410">Science and the Total Environment</a> reveals how the program’s use of smartphone e-entomology (“e” stands for electronic) is enabling the low-cost upscaling of mosquito surveillance.</p>
<p>The program involves <a href="https://www.abc.net.au/btn/newsbreak/mozzie-monitors-help-researchers/11221072">recruiting volunteers</a> to set up cheap and simple mosquito traps in their backyards, and use their smartphones to send back data on the caught mosquitoes. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/305733/original/file-20191208-90618-1ltddkg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/305733/original/file-20191208-90618-1ltddkg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/305733/original/file-20191208-90618-1ltddkg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/305733/original/file-20191208-90618-1ltddkg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/305733/original/file-20191208-90618-1ltddkg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/305733/original/file-20191208-90618-1ltddkg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/305733/original/file-20191208-90618-1ltddkg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/305733/original/file-20191208-90618-1ltddkg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mozzie Monitors volunteers used a simple BG-GAT trap to catch mosquitoes.</span>
<span class="attribution"><span class="source">Cameron Webb/NSW Health Pathology</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>A <a href="https://chuffed.org/project/mozzie-monitors">crowd-funding campaign</a> attracted donations from over 150 people to help launch the program, from which 126 people became actively involved in data collection. </p>
<p>Each participant was provided with an easy-to-use <a href="https://eu.biogents.com/bg-gat-for-homeowners/">Biogents BG-GAT (Gravid Aedes Trap)</a> and asked to email the research group with photos of collected mosquitoes. Scientists were then able to use these photos to identify and count the different species collected. This approach is called e-entomology. </p>
<p>The volunteers sent more than 10,000 photos of mosquitoes to scientists. From these, 15 different species were identified, ranging from <em>Aedes notoscriptus</em> (the common Australian backyard mosquito) to <em>Aedes camptorhynchus</em>, a mosquito flying into suburbs from nearby coastal wetlands.</p>
<p>The number of mosquitoes changed throughout the year in response to changing temperatures. Unsurprisingly, they hit their peak during summer.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/hidden-housemates-the-mosquitoes-that-battle-for-our-backyards-59072">Hidden housemates: the mosquitoes that battle for our backyards</a>
</strong>
</em>
</p>
<hr>
<h2>The value of citizen science data</h2>
<p>The Mozzie Monitors program marks the first time formal mosquito trapping has been combined with citizen science.</p>
<p>A key research question for us was: do the data collected by citizen scientists align with data collected in formal mosquito surveillance programs?</p>
<p>To test this, the data collected by Mozzie Monitors volunteers were compared to data collected from a professional program monitoring mosquitoes around urban wetlands. Mosquitoes <a href="https://entomologytoday.org/2019/04/11/mosquito-management-key-urban-wetlands/">associated with these wetlands</a> can pose pest and public health risks. </p>
<p>The citizen scientists contributed more than four times the amount of data than professional monitoring efforts. This included locally important species known to spread Ross River virus. </p>
<p>In terms of the number and diversity of mosquitoes collected, citizen science proved just as reliable as a professional program.</p>
<h2>Other victories</h2>
<p>There has been growing interest in the <a href="https://www.nature.com/articles/s41467-017-00914-9">potential of citizen science to assist the surveillance of mosquitoes</a> associated with nuisance-biting and disease risks. </p>
<p>In Brisbane, the Metro South Public Health Unit’s <a href="https://metrosouth.health.qld.gov.au/zika-mozzie-seeker">Zika Mozzie Seeker</a> program has sought to detect the arrival of exotic mosquitoes that may increase the risk of potentially serious diseases caused by the dengue, <a href="https://www.who.int/news-room/fact-sheets/detail/chikungunya">chikungunya</a>, or Zika viruses. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-mosquito-threats-shift-risks-from-our-swamps-to-our-suburbs-56350">New mosquito threats shift risks from our swamps to our suburbs</a>
</strong>
</em>
</p>
<hr>
<p>In Spain last year, citizen scientists using the <a href="https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-019-3317-y">Mosquito Alert</a> app for smartphones detected the arrival of an invasive mosquito, <em>Aedes japonicus</em>, before local authorities could.</p>
<h2>Where to now?</h2>
<p>The citizen science movement is growing across the world, promoting life-long learning among citizens. </p>
<p>It’s important communities continue to be made aware of their potential role in wildlife surveillance efforts. </p>
<p>By engaging the public in Mozzie Monitors, we’ve been able to integrate citizen science with a professional programs to boost mosquito surveillance. </p>
<p>Now, more mosquitoes can be trapped in more locations, giving health authorities a clearer picture of potential health risks. This also increases our chances of detecting invasive species that are a biosecurity threat.</p>
<p>Apart from monitoring mosquitoes, the Mozzie Monitors program is educating communities about mosquito diversity in their own backyards, and helping raise awareness of local disease risk. </p>
<p>As mosquitoes were identified during the trial, results were <a href="https://public.tableau.com/profile/mozzie.monitors#!/vizhome/MosquitoesinSouthAustralia-GoogleSheets_0/MosquitoesinSouthAustralia">made available on the research group website</a>. Citizen scientists were updated monthly on the distribution and frequency of mosquitoes in and around their suburbs. This encouraged many participants to identify mosquitoes they collected themselves.</p>
<p>The program’s next trial has already started in South Australia, and <a href="https://hehp.wordpress.com/2019/11/22/call-for-citizen-scientists-in-sa/">everyone is welcome to get involved</a>.</p><img src="https://counter.theconversation.com/content/128466/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cameron Webb and the Department of Medical Entomology, NSW Health Pathology and University of Sydney, have been engaged by a wide range of insect repellent and insecticide manufacturers to provide testing of products and provide expert advice on the biology of medically important insects. Cameron has also received funding from local, state and federal agencies to undertake research into mosquito-borne disease surveillance and management as well as risk assessment of a wide range of arthropod pests of public health importance.</span></em></p><p class="fine-print"><em><span>Craig Williams receives funding from the University of South Australia, the Western Australian Department of Health and the South Australian Department of Health. </span></em></p><p class="fine-print"><em><span>Larissa Braz Sousa receives funding from the Australian Technology Network (ATN-LATAM) Research Scholarship. </span></em></p><p class="fine-print"><em><span>Seamus Doherty receives funding from the University of South Australia, Ian Gould Experimental Science Scholarship. </span></em></p><p class="fine-print"><em><span>Stephen Rober Fricker receives funding from the from local, state and federal agencies to undertake research into mosquito-borne disease surveillance and management. </span></em></p>Nuisance-biting and mosquito-borne disease are ongoing concerns for health authorities. But an effective citizen science program is now showing how all of us can help beat the bite of mozzies.Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of SydneyCraig Williams, Associate Professor in Biology, University of South AustraliaLarissa Braz Sousa, PhD candidate on citizen science and public health, University of South AustraliaSeamus Doherty, Biologist, University of South AustraliaStephen Robert Fricker, Manager of Vector Surveillance, University of South AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1222942019-09-16T12:02:24Z2019-09-16T12:02:24ZThere’s a way for modern medicine to cure diseases even when the treatments aren’t profitable<figure><img src="https://images.theconversation.com/files/291774/original/file-20190910-190035-le6o0h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Millions of young children get malaria. These two got it in 2010.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Congo-South-Africa-Malaria-Vaccine/3260199e339e4cb893eca38e5580e2e8/1/0">AP Photo/Schalk van Zuydam </a></span></figcaption></figure><p>Strides in medicine have contributed to a <a href="https://ourworldindata.org/grapher/life-expectancy-globally-since-1770">dramatic increase in life expectancy</a> over the last century. Diseases like <a href="https://time.com/4585537/world-aids-day-hiv/">HIV</a> and <a href="https://report.nih.gov/nihfactsheets/viewfactsheet.aspx?csid=76">cervical cancer</a> that were essentially death sentences as recently as 30 years ago can now be managed with access to prescription drugs and surgical procedures.</p>
<p>Yet previously unknown or undiagnosed diseases and conditions continue to appear. And there are few to no effective treatments for many diseases and conditions.</p>
<p>Especially when the people susceptible to those illnesses tend to be <a href="https://www.clinipace.com/low-income-countries-severely-affected-infectious-diseases/">low-income</a>, the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3327542/">costly</a> fight to find cures and develop vaccines for those diseases are unlikely to be <a href="https://www.bloomberg.com/news/articles/2019-05-03/antibiotics-aren-t-profitable-enough-for-big-pharma-to-make-more">profitable</a>.</p>
<p>That is why I believe nonprofits have a vital role to play in funding these endeavors.</p>
<h2>No ‘moonshot’</h2>
<p>The research I have engaged in for most of my career as a <a href="https://scholar.google.com/citations?user=N4_3qVkAAAAJ&hl=en&oi=sra">medicinal chemist</a> has been focused on drug discovery. Much of these efforts have been aimed at treating <a href="https://www.exelixis.com/cabozantinib-development-program/">cancer</a> and <a href="https://ir.exelixis.com/news-releases/news-release-details/exelixis-collaborator-daiichi-sankyo-launches-minnebror">cardiovascular disease</a>.</p>
<p>More innovation is required for the development of new drugs that can, to name two examples, keep <a href="https://doi.org/10.1377/hlthaff.28.4.949">malaria</a> and <a href="https://dx.doi.org/10.1016%2Fj.pt.2018.07.007">dengue fever</a> at bay.</p>
<p>Unfortunately, despite the desperate need for drugs for other illnesses that mostly afflict the poor, most drugmakers are not <a href="https://www.nationalgeographic.com/science/phenomena/2015/05/23/oneill-amr-3/">pursuing new methods for treating them</a>. That is, there is no “<a href="https://www.cancer.gov/research/key-initiatives/moonshot-cancer-initiative">moonshot</a>” aimed at curing and preventing these illnesses being funded by the private sector.</p>
<p>And while federal agencies like the National Institutes of Health do provide funding for the study of <a href="https://www.hhs.gov/about/budget/fy2018/budget-in-brief/nih/index.html">infectious diseases and neurological disorders</a>, neither have adequate funding. </p>
<p>The problem is that <a href="https://www.medpagetoday.com/blogs/revolutionandrevelation/72407">private companies are largely obligated to maximize their profits</a> no matter what they produce. It therefore seems unreasonable to expect drug companies to work in areas that they suspect will not earn any money in the long run, if ever.</p>
<h2>$1.4 billion</h2>
<p>Let’s say the president of Pfizer were to announce tomorrow that the company is going to invest heavily in <a href="https://www.theguardian.com/world/2019/aug/23/malaria-will-not-be-eradicated-in-near-future-warns-who">eradicating malaria</a>. They would likely be nominated for the Nobel Peace Prize. However, the company might immediately start looking for a new top executive since eradicating malaria would easily cost Pfizer more than it could possibly recoup in sales. </p>
<p>A 2016 report by the <a href="https://doi.org/10.1016/j.jhealeco.2016.01.012">Tufts Center for the Study of Drug Development</a> estimated the cost of developing an FDA-approved prescription drug is US$1.4 billion. Production, shipping or any type of sales cost even more.</p>
<p>Meanwhile, those at the greatest risk of contracting malaria live in countries where the <a href="http://global-growing.org/en/content/fact-7-about-three-quarters-african-population-live-less-2-half-population-less-125-day">average annual income can be less than $1,000</a>. The prospects of being able to recover even a small fraction of that investment are <a href="https://health-e.org.za/2001/10/26/no-new-drugs-for-unprofitable-diseases-of-developing-world/">extremely slim</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/291644/original/file-20190909-109915-18lt48x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/291644/original/file-20190909-109915-18lt48x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/291644/original/file-20190909-109915-18lt48x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/291644/original/file-20190909-109915-18lt48x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/291644/original/file-20190909-109915-18lt48x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/291644/original/file-20190909-109915-18lt48x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/291644/original/file-20190909-109915-18lt48x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/291644/original/file-20190909-109915-18lt48x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bringing a new drug to market from experimentation through marketing costs a small fortune.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/flask-scientist-hand-dropping-chemical-liquid-457937065?src=1-SETlpvTrCJ8KDprGS8uQ-1-34">totojang1977/Shutterstock.com</a></span>
</figcaption>
</figure>
<h2>Superbugs</h2>
<p>Before you dismiss this as a problem unlikely to affect your own well-being, consider the health risks posed by <a href="https://www.cdc.gov/features/antibiotic-resistance-global/index.html">antibiotic resistance</a>.</p>
<p>The development of bacterial resistance to common drugs like <a href="https://www.drugs.com/article/antibiotic-resistance.html">amoxicillin</a>, <a href="https://www.webmd.com/sexual-conditions/antibiotic-resistant-std-faq">azithromycin</a> and other similar drugs has given rise to the discovery of other drugs such as <a href="https://www.mdedge.com/ccjm/article/95526/drug-therapy/vancomycin-50-something-year-old-antibiotic-we-still-dont-understand">vancomycin</a> and <a href="https://www.britannica.com/science/methicillin">methicillin</a>. However, new strains of bacteria have come along that are <a href="https://www.the-hospitalist.org/hospitalist/article/121560/antimicrobial-resistant-infections/superbug-infections-rise-no-antibiotic">resistant to even these last lines of defense</a>. </p>
<p>Modern medicine has no known treatments against these so-called “superbugs.”</p>
<p>Absent new drugs to treat such infections, a person who gets a scratch that becomes infected could be at risk of dying. </p>
<p>With that in mind, there is a clear need for new antibiotic drug discovery. Yet <a href="https://www.businessinsider.com/major-pharmaceutical-companies-dropping-antibiotic-projects-superbugs-2018-7">virtually all drugmakers have moved away from this line of business</a> for one obvious reason.</p>
<p>If a new drug were identified tomorrow, it would obviously be held out as the new <a href="https://www.healthcaredive.com/news/without-more-stewardship-superbugs-could-kill-thousands-more-americans-ann/541832/">last line of resistance</a> for the treatment of bacterial infections. How could a company justify spending the requisite $1.4 billion to develop a drug that would only be used as a drug of last resort?</p>
<p>If, say, 1,000 patients needed the drug in a given year, could a company realistically expect each patient over 10 years to pay $140,000 just to recover the initial cost of the discovery? Of course not. But it might make sense for nonprofits to do this if that’s their mission.</p>
<h2>Promising examples</h2>
<p>There are nonprofits who engage in drug discovery for these neglected diseases. One good example is <a href="https://www.mmv.org/">Medicines for Malaria Venture</a>, a group of scientists based in Switzerland dedicated to reducing the burden of malaria on a global scale. </p>
<p><a href="https://www.gatesfoundation.org/">The Bill and Melinda Gates Foundation</a>, <a href="https://www.oneworldhealth.com/">OneWorld Health</a>, the <a href="https://www.newtbdrugs.org/">Working Group on New Tuberculosis Drugs</a> and the <a href="https://www.milkeninstitute.org/centers/center-for-public-health">Milken Institute Center for Public Health</a> are among the best-known organizations working to realize these important goals <a href="https://www.mmv.org/partnering/our-donors/current-donors">without being subjected to stockholder pressure</a>.</p>
<p>These efforts have given rise to <a href="https://www.mmv.org/research-development/mmv-supported-projects">nearly a dozen new approved drugs to treat malaria</a>, and they have made progress toward creating vaccines that might stem the spread of diseases like <a href="https://www.who.int/csr/resources/publications/ebola/ebola-ring-vaccination-results-12-april-2019.pdf">Ebola</a> and <a href="https://www.nih.gov/news-events/news-releases/nih-begins-clinical-trial-live-attenuated-zika-vaccine">Zika</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/291643/original/file-20190909-109927-1vxzs3z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/291643/original/file-20190909-109927-1vxzs3z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/291643/original/file-20190909-109927-1vxzs3z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/291643/original/file-20190909-109927-1vxzs3z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/291643/original/file-20190909-109927-1vxzs3z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/291643/original/file-20190909-109927-1vxzs3z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/291643/original/file-20190909-109927-1vxzs3z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/291643/original/file-20190909-109927-1vxzs3z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The bacteria that causes tuberculosis.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/bacteria-mycobacterium-tuberculosis-causative-agent-3d-1013219203?src=qmHc3gUU1FUp62X5iZ4ujw-1-1">Kateryna Kon/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>The <a href="https://www.tballiance.org/">TB Alliance</a> is an international nonprofit dedicated to the discovery, development and delivery of better, faster-acting and affordable tuberculosis drugs that are available to <a href="https://www.cdc.gov/tb/statistics/default.htm">those who need them</a>.</p>
<p>With support from the <a href="https://www.tballiance.org/about/donors">Gates Foundation</a> and government agencies from around the world, the alliance gained FDA approval for <a href="https://www.fda.gov/news-events/press-announcements/fda-approves-new-drug-treatment-resistant-forms-tuberculosis-affects-lungs">pretomanid</a>, its new drug that can treat multidrug-resistant TB, which an estimated <a href="https://www.who.int/tb/areas-of-work/drug-resistant-tb/en/">600,000 people develop every year</a>.</p>
<p>What I found to be especially noteworthy is that the alliance facilitated and funded the efforts that resulted in a new lifesaving treatment without creating its own lab. Instead, it coordinated the efforts of other researchers already conducting TB investigations in many countries. </p>
<p>The continued support by government agencies, private donors and nonprofits of these ventures could prove paramount to the survival of the human species. While their continued funding is clearly needed to provide these critical medicines, all of us are fortunate to have organizations such as this working for the betterment of mankind.</p>
<p>[ <em><a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=expertise">Expertise in your inbox. Sign up for The Conversation’s newsletter and get a digest of academic takes on today’s news, every day.</a></em> ]</p><img src="https://counter.theconversation.com/content/122294/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Leahy owns shares of stock in a variety of pharmaceutical companies, including Exelixis, where he worked for 14 years. His research is funded in part by funding agencies such as the National Institutes of Health and the National Science Foundation.</span></em></p>There’s a big market for new treatments for TB, malaria and other ailments. But most of these diseases afflict low-income people unable to pay for medicine.James Leahy, Professor of Chemistry; Interim Chair of the Chemistry Department, University of South FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1219912019-08-21T12:57:07Z2019-08-21T12:57:07ZWhy the DRC Ebola outbreak was declared a global emergency and why it matters<figure><img src="https://images.theconversation.com/files/288869/original/file-20190821-170946-fmp18c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">shutterstock</span> </figcaption></figure><p>In mid-July the WHO declared the Ebola epidemic in the Democratic Republic of Congo (DRC) a <a href="https://www.who.int/news-room/detail/17-07-2019-ebola-outbreak-in-the-democratic-republic-of-the-congo-declared-a-public-health-emergency-of-international-concern">Public Health Emergency of International Concern</a>. At the time over 2000 cases had been reported. A factor that <a href="https://www.who.int/ihr/procedures/statement-emergency-committee-ebola-drc-july-2019.pdf">is likely to have influenced the decision</a> was that a new case had been noted near Goma near the border with Rwanda. The fear was that the disease would spread through Goma, a city of 2 million people, and that it would rapidly cross into Rwanda, Uganda and Burundi.</p>
<p>The decision was taken by the International Health Regulations Emergency Committee. It made its decision at the fourth meeting it had held since the DRC epidemic began a year ago. </p>
<p>Global efforts to manage epidemics are documented as far back as <a href="https://www.historytoday.com/archive/black-death-greatest-catastrophe-ever">the black plague in Europe in the 14th century</a>, where borders were monitored for infections. Since that time, rules have been developed and honed to keep up with the emergence of new diseases as well as with the growing complexities of a world that’s increasingly connected through travel and trade.</p>
<p>An epidemic refers to a specific pattern of exponential growth in infections – above the usual expected occurrence – over a short time frame, usually days or weeks. Epidemics have an acutely disruptive and immediate impact that requires urgent attention. </p>
<p>Ebola is an example. Any delay in response can be critical because of the exponential growth in case numbers. This was seen during the outbreak in West Africa in 2014. In March there were only hundreds of cases. Within months the number had spiked to over <a href="https://jglobalbiosecurity.com/articles/36/">28,000</a>. Most could have been prevented if there had been a more immediate response. </p>
<p>Other diseases such as malaria or HIV can affect large numbers of people too, but are not epidemic diseases. Changes to these endemic infections occur more slowly, typically over years.</p>
<p>Measles is another epidemic disease. Even though there’s a cheap and effective vaccine and vaccination rates are high in many countries, it remains a leading killer in the world. <a href="https://www.sciencedirect.com/science/article/pii/S0264410X18308387?via%3Dihub">Outbreaks</a> continue to occur in low and high income settings. So why hasn’t it been declared a public health emergency of international concern? </p>
<p>The seriousness of an epidemic is a function of several factors. These <a href="https://www.sciencedirect.com/science/article/pii/S002074891400234X">include</a> the degree of contagiousness and potential for rapid spread, severity of infection, case fatality rate (the number of infected people who die), availability of vaccines or treatment, impact on travel and trade, and the socioeconomic context. </p>
<p>Measles is in fact much more contagious than Ebola. But the case fatality rate is much lower – 0.2% compared to 50%-90% for Ebola. </p>
<p>The context of the epidemic also matters. For example the risk from Ebola <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/risa.12876">was much higher in West Africa</a> in 2014 where the case fatality rate was over <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(14)61706-2/fulltext">70%</a>, compared to only 20% in the US where high quality healthcare was available. </p>
<p>So, the combination of a serious epidemic disease such as Ebola, with a high case fatality rate, occurring in a low income setting beset by conflict, as well as the risk of spread to other countries, would have influenced the WHO decision on Ebola in the DRC. Perhaps the delay in making the decision in the 2014 in West Africa – now recognised <a href="https://jglobalbiosecurity.com/articles/36/">as a missed opportunity</a> – may also have been a consideration.</p>
<h2>What it triggers</h2>
<p>Declaration of a “public health emergency of international concern” by the WHO triggers a number of things. </p>
<p>The first is that it signals a commitment to provide international resources for the response. </p>
<p>The second is that it enables other provisions of the <a href="https://www.who.int/features/qa/emergency-committees/en/">International Health Regulations</a>. These originated from the International Sanitary Regulations of <a href="https://apps.who.int/iris/handle/10665/85636">the mid 1900s</a>, which were used to control cholera epidemics. At this time, there was increasing awareness of the social and economic affects of epidemic diseases across borders, as well as concern about undue interference with trade. </p>
<p>In 1969 the regulations were <a href="https://www.who.int/ihr/current/en/">renamed</a> the “International Health Regulations” by the World Health Organisation. They were then modified in 1973 and 1981. But even then they provided a framework for only 3 diseases – cholera, yellow fever and plague. The principles behind them was </p>
<blockquote>
<p>maximum security against the international spread of diseases with a <a href="https://www.who.int/trade/distance_learning/gpgh/gpgh8/en/index7.html">minimum interference with world traffic</a>. </p>
</blockquote>
<p>In 1995, formal revision commenced to expand the scope of the regulations with six proposed categories of <a href="https://www.asil.org/insights/volume/8/issue/8/revision-world-health-organizations-international-health-regulations">reportable syndromes</a>: </p>
<ul>
<li><p>acute haemorrhagic fever syndrome,</p></li>
<li><p>acute respiratory syndrome, </p></li>
<li><p>acute diarrhoeal syndrome, </p></li>
<li><p>acute jaundice syndrome, </p></li>
<li><p>acute neurological syndrome, and </p></li>
<li><p>other notifiable syndromes. </p></li>
</ul>
<p>In addition, five factors were proposed to determine if a cluster of syndromes was urgent and of international importance. These were rapid transmission in the community, unexpectedly high case fatality ratio, a newly recognised syndrome, high political and media profile, and trade or travel restrictions. </p>
<p>The last revision to the regulations was done in 2005 following the <a href="https://www.asil.org/insights/volume/8/issue/7/sars-and-international-law">SARS epidemic of 2003</a>.</p>
<p>The five substantive changes from the prior version were: </p>
<ul>
<li><p>a dramatic expansion of the scope of the regulations,</p></li>
<li><p>the creation of obligations on states to develop minimum core surveillance and response capacities,</p></li>
<li><p>granting WHO the authority to access and use non-governmental sources of surveillance information,</p></li>
<li><p>granting WHO the power to declare a public health emergency of international concern and to issue recommendations on how states-parties deal with it; and </p></li>
<li><p>the <a href="https://www.repository.law.indiana.edu/cgi/viewcontent.cgi?article=1399&context=facpub">incorporation of human rights</a> concepts into the implementation of the regulations.</p></li>
</ul>
<p>The regulations set down how an emergency will be managed. This includes setting up a roster of experts appointed by the Director General of WHO in all relevant fields of expertise. Then an emergency committee is drawn from this roster for advice. The committee has to decide on a range of issues to do with managing the epidemic. This includes whether an event constitutes a global emergency and when it should be ended.</p>
<p>But the regulations can only go so far. Many countries cannot comply with them due to lack of resources. And their contribution to controlling the 2014 Ebola outbreak is unclear, as it was invoked <a href="https://www.who.int/mediacentre/news/statements/2014/ebola-20140808/en/">late in the epidemic</a>. </p>
<p>Since the Ebola epidemic of 2014 the regulations have only been invoked twice, for the <a href="https://www.who.int/ihr/emergency-committee-zika/en/">Zika virus epidemic</a> in 2016 and for the Ebola epidemic in DRC in 2019. </p>
<p>In the case of Zika virus, case fatality was low. But the decision to declare a global emergency was <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)00320-2/fulltext">because there was so much that wasn’t known</a> about birth defects and neurological illness caused by the virus.</p>
<h2>More than a health issue</h2>
<p>Many of the problems of global emergencies are not specific health problems, but relate to civil society, community engagement, law and order and border control. In the 2014 Ebola epidemic, for example, a health promotion team <a href="https://www.washingtonpost.com/news/to-your-health/wp/2014/09/18/missing-health-workers-in-guinea-were-educating-villagers-about-ebola-when-they-were-attacked/">was massacred in Guinea</a> because local people were fearful of outsiders coming to their village. </p>
<p>Similar issues have arisen in the DRC, including <a href="https://www.theguardian.com/global-development/2019/feb/28/arsonists-attack-ebola-clinics-in-drc-as-climate-of-distrust-grows">burning down</a> of treatment centres in Katwa and Butembo. </p>
<p>This highlights the importance of grassroots community empowerment and mobilisation, engagement of local leaders, cultural sensitivity and risk communication in epidemic response. </p>
<p>The environment of violence, conflict and lack of trust surrounding the current epidemic would no doubt have been part of the deliberations of the WHO expert committee. The decision to declare a public health emergency of international concern in July 2019 when there were around 2000 cases was prudent given the lessons learned after delaying the declaration of the 2014 epidemic.</p><img src="https://counter.theconversation.com/content/121991/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>C Raina MacIntyre currently receives funding from NHMRC, including a Centre for Research Excellence and a Principal Research Fellowship. She has received funding or in-kind support for investigator driven research from Sanofi, Seqirus, Pfizer and Merck. She has received sponsorship for workshops from Emergent Biosolutions, Bavarian Nordic, Siga Technologies and Meridien Medical Technologies. </span></em></p><p class="fine-print"><em><span>Obijiofor Aginam was a recipient of the Social Sciences and Humanities Research Council (SSHRC) of Canada grant (2005-2008); Social Science Research Council (SSRC) of New York grant (2004-2005).</span></em></p>Timing is everything when it comes to making a decision about declaring a disease outbreak a public health emergency of international concern.C Raina MacIntyre, Professor of Global Biosecurity, NHMRC Principal Research Fellow, Head, Biosecurity Program, UNSW SydneyObijiofor Aginam, Deputy-Director & Head of Governance for Global Health, International Institute for Global Health (UNU-IIGH), United Nations UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1121042019-02-22T06:01:07Z2019-02-22T06:01:07ZVenezuela: region’s infectious crisis is a disaster of hemispheric proportions<p>Over the last two decades, Venezuela has entered a deep socioeconomic and political crisis. Once recognised as a regional leader for public health and disease control, Venezuela’s healthcare and health research infrastructure has fallen into a state of collapse, creating a severe humanitarian crisis and a major outbreak of infectious disease.</p>
<p>This week, we published <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(18)30757-6/fulltext">the first comprehensive assessment</a> of the vector-borne disease outbreak that is assailing the country. Vector-borne diseases are those spread by insects – mosquitos, sand flies, kissing bugs and others. The “we” is a global consortium of authors, many of whom are Venezuelan doctors and academics working in the country under exceptionally difficult conditions. Others include Colombian, Brazilian and Ecuadorian academics who are witnessing the crisis unfold: Venezuelan refugees on the streets of their cities, diseases (malaria, Chagas disease, measles, diphtheria) spreading through porous land borders, and regional disease outbreaks of unprecedented proportions. </p>
<p>I first travelled to Venezuela in the early 2000s to study Chagas disease, a single-celled parasite spread by the kissing bug, a blood-sucking insect that infests the walls of adobe houses. Chagas disease is a silent killer. Once infected, the parasite can lie dormant for decades in its human host before causing fatal heart disease in middle age. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/259976/original/file-20190220-148520-1p7ff18.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/259976/original/file-20190220-148520-1p7ff18.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/259976/original/file-20190220-148520-1p7ff18.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/259976/original/file-20190220-148520-1p7ff18.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/259976/original/file-20190220-148520-1p7ff18.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/259976/original/file-20190220-148520-1p7ff18.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/259976/original/file-20190220-148520-1p7ff18.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Kissing bug: spreader of Chagas disease.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/609147728?src=aSQuQDRj-oPyo2lxQ83yLw-1-23&size=medium_jpg">schlyx/Shutterstock</a></span>
</figcaption>
</figure>
<p>You can’t travel to Venezuela, including to the communities where I worked in the Llanos (plains) of the west, without being entranced by the beauty of the landscape and the friendliness of its people. From the laboratory in the Institute of Tropical Medicine in Caracas, where I was taken under the wing of Professor Hernan Carrasco and his team, dancing salsa between the benches on a Friday night, to the villages where we slept under the stars in hammocks while the inhabitants sang joropo music, it is a thoroughly welcoming place.</p>
<p>Venezuela is also a place of extreme inequality. You only have to look up from the glitzy streets of downtown Caracas to the mud and brick ranchos clustered on the hillsides above to appreciate that. It is this inequality that drove the socialist revolution, and while times were good – and oil prices high – much of Venezuela’s wealth found its way into the hands of those who needed it most. Declining oil prices, corruption and mismanagement have changed all that. Alongside economic collapse has come a collapse in basic healthcare, an exodus of medical professionals, and a massive upsurge in disease.</p>
<h2>Fragmented information</h2>
<p>At the core of the infectious disease crisis in Venezuela is the lack of reliable data. Either through denial, a lack of resource, or both, the Venezuelan state is reneging on its responsibility to report on the extent of current outbreaks. The purpose of our recent review was to draw together fragmented information from Venezuelan civil societies, researchers, international organisations and neighbouring countries to get the best estimate of what is actually going on. Over 400,000 cases of malaria in 2017, 15% of the rural population infected with Chagas disease, surging dengue, Chikungunya and Zika infections. The picture is grim. </p>
<p>Health is highly politicised in Venezuela and working as a researcher is not without risk. My collaborators have been threatened with jail and having their medical licenses suspended simply for reporting outbreaks in the scientific literature. The Institute of Tropical Medicine where I worked has been raided by colectivos (community organisations that supports the Venezuelan government), microscopes smashed, medical records destroyed, hard drives ripped out of computers. </p>
<p>The centre of the current malaria epidemic in southeastern Bolivar state is also the centre of state-sponsored illegal gold mining in Venezuela. The tonnes of gold recently shipped by the Maduro regime to Russia and Turkey is soaked in the sweat and blood of poor Venezuelans, sleeping with their families beside mosquito-infested mining pits. Drawing attention to this malaria epidemic is drawing attention to the ecological and humanitarian disaster in this region where mercury is polluting pristine rivers and thousands are dying for want of antimalarial drugs that the government will not or, more likely, cannot supply. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/259858/original/file-20190219-43258-1nfube.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/259858/original/file-20190219-43258-1nfube.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/259858/original/file-20190219-43258-1nfube.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/259858/original/file-20190219-43258-1nfube.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/259858/original/file-20190219-43258-1nfube.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/259858/original/file-20190219-43258-1nfube.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/259858/original/file-20190219-43258-1nfube.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Illegal gold mining in Bolivar state.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Venezuelans are resilient and resourceful people. The Venezuelan researchers still living and working in the country are a testament to that, as is the support they receive from the diaspora of Venezuelans forced to live abroad. In recognising the regional aspect to the crisis, the spillover of disease in the region and the millions of refugees, we hope our review will galvanise international organisations to act. I’m optimistic that we are reaching a turning point in a crisis ten years in the making. I fervently hope the spirit of Venezuelans will break through. I hope that scientists will dance salsa again – and soon.</p><img src="https://counter.theconversation.com/content/112104/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Martin Llewellyn does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New survey of insect-borne disease in Venezuela.Martin Llewellyn, Senior Lecturer, Institute of Biodiversity Animal Health & Comparative Medicine, University of GlasgowLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1109782019-02-14T11:48:45Z2019-02-14T11:48:45ZWhy it’s so difficult for scientists to predict the next outbreak of a dangerous disease<figure><img src="https://images.theconversation.com/files/258030/original/file-20190208-174890-1x41zk6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">_Aedes aegypti_ mosquitoes, responsible for transmitting Zika.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Brazil-Zika-Babies/bceee084fdda49099573cde276c72239/1/1">AP Photo/Felipe Dana</a></span></figcaption></figure><p>A two-year-old boy in rural Guinea died of Ebola in December 2014. Over the next two years, almost <a href="https://www.cdc.gov/vhf/ebola/history/2014-2016-outbreak/index.html">30,000 people in West Africa would be infected with the Ebola virus</a>. </p>
<p>Why, unlike the previous 17 Ebola outbreaks, did this one grow so large, so quickly? What, if anything, can be done to prevent future outbreaks? These questions, along with many others, are at the heart of the nascent scientific field of outbreak forecasting. And the stakes couldn’t be higher. In January, the <a href="https://www.weforum.org/press/2019/01/risks-to-global-businesses-from-new-era-of-epidemics-rival-climate-change/">World Economic Forum</a> called pandemics one of the greatest risks to business and human life. </p>
<p>Over the last several centuries, scientists have become ever better at predicting many aspects of the world, including the orbit of planets, the ebb and flow of tides and the paths of hurricanes. The ability to understand natural and physical systems well enough to make accurate forecasts is perhaps one of humanity’s greatest achievements. </p>
<p>Much of this success at forecasting begins with Isaac Newton’s fundamental insight that there are unchanging universal laws that govern the natural phenomena around us. The ability to rapidly perform large calculations has fostered the Newtonian perspective that, given enough data and computing power, most complex phenomena can be predicted. </p>
<p>There are, however, limits. <a href="https://scholar.google.com/citations?user=rHUzZs0AAAAJ&hl=en">As scientists</a> <a href="https://scholar.google.com/citations?user=B9FcowkAAAAJ&hl=en">who study</a> <a href="https://scholar.google.com/citations?user=ZFsl9WsAAAAJ&hl=en">these kinds</a> of predictive systems, we doubt that it will be possible to predict exactly what will happen next in a disease outbreak, because the most important variables can change so much from one outbreak to another. </p>
<p>This is why, as with weather forecasting, gathering real-time data is likely essential for advancing the scientific community’s ability to predict outbreaks. </p>
<h2>Capricious epidemics</h2>
<p>The idea that scientists can model epidemics is based on the notion that the trajectory of each outbreak is predictable because of its intrinsic and unchanging properties.</p>
<p>Say a disease is caused by a transmissible pathogen. The infectiousness of that disease can be encapsulated in a number called the “basic reproductive ratio,” or R0, <a href="https://doi.org/10.1098/rsif.2009.0386">a number describing how widely a pathogen is likely to spread in a given population</a>. </p>
<p>If epidemiologists know enough about a pathogen’s R0, the hope is that they can predict aspects of its next outbreak – and hopefully prevent small-scale outbreaks from becoming large-scale epidemics. They might do this by mobilizing resources to areas where pathogens have especially high R0 values. Or they might limit interactions between the carriers of disease and the most susceptible members of a given society, often children and the elderly. </p>
<p>In this way, R0 is interpreted as an immutable number. But modern studies demonstrate that this not the case.</p>
<p>For example, consider the Zika virus epidemic. For this disease, <a href="https://arxiv.org/abs/1604.04008">R0 ranged from 0.5 to 6.3</a>. This is a remarkable span, ranging from a disease that will dissipate on its own to one that will cause a long-term epidemic. </p>
<p>One might think that this broad range of R0 values for Zika stems from statistical uncertainty – that maybe scientists just need more data. But that would be mostly incorrect. <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1006633">For Zika, myriad factors</a>, from climate and mosquitoes to the presence of other related viruses like Dengue and the <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1006633">role of sexual transmission</a>, all lead to different R0 values in different settings. </p>
<p>It turns out that the features of an epidemic – the pathogen’s contagiousness, rate of transmission, availability of vaccines and so on – change so rapidly during the course of a single outbreak that <a href="https://arxiv.org/abs/1703.07317">scientists are able to predict dynamics only within the course of that outbreak</a>. In other words, studying the Ebola virus disease outbreak in April 2014 may help scientists to understand an Ebola outbreak in that same setting the next month, but it’s often much less helpful for understanding the dynamics of future Ebola epidemics, such as the one that happened in May 2018.</p>
<p>Epidemics often aren’t neat and bundled phenomena. They are noisy occurrences where many variables play essential, but shifting, roles. There is no underlying truth of the disease – only an unstable collection of details that vary, often becoming entangled, as the disease spreads.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/258337/original/file-20190211-174864-yjss91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/258337/original/file-20190211-174864-yjss91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/258337/original/file-20190211-174864-yjss91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=391&fit=crop&dpr=1 600w, https://images.theconversation.com/files/258337/original/file-20190211-174864-yjss91.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=391&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/258337/original/file-20190211-174864-yjss91.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=391&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/258337/original/file-20190211-174864-yjss91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=492&fit=crop&dpr=1 754w, https://images.theconversation.com/files/258337/original/file-20190211-174864-yjss91.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=492&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/258337/original/file-20190211-174864-yjss91.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=492&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Amid a measles outbreak that has sickened people in Washington state and Oregon, lawmakers heard public testimony on the bill on Feb. 8 that would remove parents’ ability to claim a philosophical exemption to opt their school-age children out of the combined measles, mumps and rubella vaccine.</span>
<span class="attribution"><span class="source">AP Photo/Ted S. Warren</span></span>
</figcaption>
</figure>
<h2>Better predictions</h2>
<p>If scientists aren’t confident that they can understand epidemiological systems well enough to predict the behavior of related ones, why bother studying them? </p>
<p>The answer might reside in what we call a “soft physics” of prediction: Scientists should stop assuming that every outbreak follows the same rules. When comparing one outbreak with another, they should keep in mind all of the contextual differences between them.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/258339/original/file-20190211-174870-2upop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/258339/original/file-20190211-174870-2upop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/258339/original/file-20190211-174870-2upop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=706&fit=crop&dpr=1 600w, https://images.theconversation.com/files/258339/original/file-20190211-174870-2upop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=706&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/258339/original/file-20190211-174870-2upop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=706&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/258339/original/file-20190211-174870-2upop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=888&fit=crop&dpr=1 754w, https://images.theconversation.com/files/258339/original/file-20190211-174870-2upop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=888&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/258339/original/file-20190211-174870-2upop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=888&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The H1N1 influenza virus.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:H1N1_influenza_virus.jpg">CDC</a></span>
</figcaption>
</figure>
<p>For example, biologists have uncovered many details about influenza infections. They know how the viruses bind to host cells, how they replicate and how they evolve resistance to antiviral drugs. But one epidemic might have started when a large population used public transportation on a certain day of the month, while another might have been initiated by a congregation at a religious service. Though both outbreaks are rooted in the same infectious agent, these and many other differences in their particulars mean that scientists may need to reframe how they model how each progresses. </p>
<p>To understand these particulars better, scientists need significant investments in real-time data. Consider that the National Weather Service spends over <a href="https://www.corporateservices.noaa.gov/nbo/fy18_bluebook/FY18-BlueBook.pdf">US$1 billion</a> per year gathering data and making forecasts. The CDC spends only a quarter as much on public health statistics and <a href="https://www.cdc.gov/budget/documents/fy2018/fy-2018-cdc-budget-overview.pdf">has no dedicated budget for forecasting</a>.</p>
<p>Disease surveillance remains one of the highest-stakes areas of science. A careful consideration for unique circumstances underlying outbreaks and more responsible collection of data could save thousands of lives.</p><img src="https://counter.theconversation.com/content/110978/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>C. Brandon Ogbunu receives funding from the National Science Foundation. </span></em></p><p class="fine-print"><em><span>Samuel V. Scarpino works/consults/holds options for Northeastern University, Dharma Platform, IPRD Group, ThinkMD, BioFire Diagnostics, and Iliad Biotechnologies. </span></em></p><p class="fine-print"><em><span>Randall Harp does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>In January, measles returned to the Pacific Northwest, while Ebola resurged in the Congo. It would take a lot more research for scientists to be able to stop threats like these in their tracks.C. Brandon Ogbunu, Assistant Professor of Ecology and Evolutionary Biology, Brown UniversityRandall Harp, Associate Professor of Philosophy, University of VermontSamuel V. Scarpino, Assistant Professor of Network Science, Northeastern UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1046132018-12-21T11:42:18Z2018-12-21T11:42:18ZUsing gene drives to control wild mosquito populations and wipe out malaria<figure><img src="https://images.theconversation.com/files/251036/original/file-20181217-185258-5nhh7t.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A female _Anopheles stephensi_ mosquito bites a human to get a blood meal through its pointed proboscis. A droplet of blood is expelled from the abdomen after having engorged itself. </span> <span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/7/7e/Anopheles_stephensi.jpeg">Jim Gathany/Wikimedia Commons</a></span></figcaption></figure><p>What is the deadliest animal on earth? It’s a question that brings to mind fearsome lions, tigers, sharks and crocodiles. But the answer is an animal that is no more than 1 centimeter long. </p>
<p>A few mosquito species, out of the thousands that populate different environments, are the deadliest animals on earth. <em>Anopheles</em> mosquitoes alone, transmit malaria through their bite and annually infect <a href="https://www.who.int/news-room/fact-sheets/detail/malaria">more than 200 million people</a>, and are responsible for <a href="http://www.who.int/news-room/fact-sheets/detail/malaria">400,000 deaths per year</a>, of which 70 percent are children under the age of 5. </p>
<p>Other mosquito species also transmit diseases – dengue, West Nile and Zika – through their bite. </p>
<p>We are geneticists at Imperial College in London who focus on the mosquito and its role as a vector of disease. For more than 20 years, we’ve been focusing on the development of genetically manipulated mosquitoes. That is because decades of malaria control has taught us that the most effective strategy to prevent malaria is to control the mosquito itself. Years of research has led to the development of the ultimate and sophisticated genetic tool called “gene drive.” When correctly engineered, it can eliminate mosquito populations housed in cages in the lab.</p>
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<img alt="" src="https://images.theconversation.com/files/250964/original/file-20181217-185261-a5yeyx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/250964/original/file-20181217-185261-a5yeyx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/250964/original/file-20181217-185261-a5yeyx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/250964/original/file-20181217-185261-a5yeyx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/250964/original/file-20181217-185261-a5yeyx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/250964/original/file-20181217-185261-a5yeyx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/250964/original/file-20181217-185261-a5yeyx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A warming climate is expected to increase mosquito populations worldwide.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/plenty-mosquitos-window-on-german-beach-1033758127?src=uIylu9v5_-yG7IEOWyKeBQ-2-51">HAPPY_PICTURE/SHutterstock.com</a></span>
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<h2>We fight mosquito-borne diseases every day</h2>
<p>Only female mosquitoes bite humans. They drink human blood to gather nutrients to produce their eggs. If the female mosquito is infected with a virus or a parasite, <a href="https://www.cdc.gov/features/stopmosquitoes/index.html">it will pass the infection</a> onto the bitten person. Later, if an uninfected mosquito bites the newly infected human, it will pick up the microorganism and it too will be able to spread the disease to other individuals. </p>
<p>For a disease like malaria, which is a threat to nearly half of the world’s population, public health initiatives have used a variety of methods to target the malaria parasite itself, like vaccines and drugs. Other methods – including pesticides, fumigation, bed nets and removal of mosquitoes’ habitats – strive to reduce either the contact with, or the number of, mosquitoes. But we believe that <a href="http://www.who.int/news-room/fact-sheets/detail/malaria">targeting the mosquito</a> is the most effective way to reduce malaria cases worldwide. </p>
<p>Now in Africa, <a href="http://www.who.int/news-room/fact-sheets/detail/malaria">where the malaria burden is highest</a>, spraying insecticide indoors and sleeping under insecticide-laced bed nets, are the most effective ways to rapidly reduce malaria transmission. These control measures and interventions have helped reduce the malaria burden dramatically in many places. Since 2010 the <a href="http://www.who.int/news-room/fact-sheets/detail/malaria">mortality rates caused by malaria</a> have fallen by 35 percent among children under the age of 5. </p>
<p>These methods, though, are not sustainable and they need to be implemented on a large scale to reach their full potential. This became obvious between 2014 and 2016, which marked the first time since 2010 in which <a href="http://www.who.int/malaria/media/world-malaria-report-2017/en/">malaria cases have increased</a>, breaking the declining trend observed during the years before. Mosquitoes are developing <a href="http://www.who.int/malaria/media/world-malaria-report-2017/en/">resistance to antimalarial drugs and insecticides</a>, and we are running out of options and time. </p>
<h2>A new approach</h2>
<p>To achieve malaria eradication, public health researchers must upgrade our arsenal. To move toward this goal we, the <a href="https://www.imperial.ac.uk/people/a.drcrisanti">Crisanti</a> lab here at Imperial College, have been working on a plan to do just that.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/250966/original/file-20181217-185255-2jbyhg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/250966/original/file-20181217-185255-2jbyhg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=459&fit=crop&dpr=1 600w, https://images.theconversation.com/files/250966/original/file-20181217-185255-2jbyhg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=459&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/250966/original/file-20181217-185255-2jbyhg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=459&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/250966/original/file-20181217-185255-2jbyhg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=576&fit=crop&dpr=1 754w, https://images.theconversation.com/files/250966/original/file-20181217-185255-2jbyhg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=576&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/250966/original/file-20181217-185255-2jbyhg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=576&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Normal and infected red blood cells. Malaria is a disease caused by a parasite called <em>Plasmodium</em> that is spread to humans through the bite of an infected mosquito.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/malaria-normal-infected-red-blood-cells-263076182?src=QcfzV5_nI7ij2Ekvu08uUg-1-53">Designua/Shtterstock.com</a></span>
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<p>Recently, a technology called <a href="http://doi.org/10.1126/science.1225829">CRISPR</a> <a href="http://doi.org/10.1093/hmg/ddu125">has</a> been developed that allows scientists to edit DNA with great efficiency. Researchers across the world are using CRISPR to modify mosquito DNA with the goal of eliminating mosquito-borne diseases, such as malaria. In our lab, we have developed what is perhaps the most <a href="http://doi.org/10.1038/nbt.4245">advanced</a> use of the technology ever proposed. It is called “gene drive.” This type of genetic modification has the ability to spread a trait in a wild population, overriding the classic laws of heredity. </p>
<p>DNA that is transmitted from one parent, from one generation to the next via the classic laws of heredity, is inherited by only half of the progeny of each generation. This keeps the frequency of that genetic modification or trait in the population of mosquitoes the same. </p>
<p>Gene drives are inherited by more than 50 percent of the progeny. This gives them the ability to progressively increase the frequency of a trait over subsequent generations, which is an advantage over the potential use of other GM mosquitoes. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/251040/original/file-20181217-185255-1m5rnuq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/251040/original/file-20181217-185255-1m5rnuq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=365&fit=crop&dpr=1 600w, https://images.theconversation.com/files/251040/original/file-20181217-185255-1m5rnuq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=365&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/251040/original/file-20181217-185255-1m5rnuq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=365&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/251040/original/file-20181217-185255-1m5rnuq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=459&fit=crop&dpr=1 754w, https://images.theconversation.com/files/251040/original/file-20181217-185255-1m5rnuq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=459&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/251040/original/file-20181217-185255-1m5rnuq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=459&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Top: CRISPR/Cas9-based gene drives carry a molecular scissor, called Cas9 endonuclease, and a guide RNA (gRNA), which are essential for cutting the DNA at a specific site within the genome. Human and mosquitoes carry two copies of each gene for every trait. When the DNA is cut, the repair machinery copies information from Allele 1 - which carries the code for the gene drive and the cargo DNA that causes female sterility - to the broken Allele 2. In this way the gene drive is present in every mosquito in the progeny. Bottom: Following the classic laws of inheritance, traits (red) are inherited by only half the progeny from each generation (left), which is not enough to spread the trait within a population. In animals modified with a gene drive, the trait is spread to all the progeny in every generation. As the modified animals mate with other wild-type members of the species (blue), the trait quickly spreads to all the members of the population.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/4/4e/Gene_Drive.png">Mariuswalter</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<h2>Ethics of altering wild mosquito populations</h2>
<p>We have <a href="http://doi.org/10.1038/nbt.3439">designed a gene drive</a> that targets fertility genes that are <a href="http://doi.org/10.1038/nbt.4245">essential for the development of the female mosquito</a>. When these genes are disrupted, the female insect is unable to bite or produce offspring. </p>
<p>The advantage of gene drives is that we can target only the <em>Anopheles gambiae</em> species – one of the primary vectors that carry the disease in sub-Saharan Africa – without affecting those that do not.</p>
<p>When we tested our technology in the lab, we were able to spread this trait to 100 percent of the mosquito population in the cages. The consequence of producing normal male mosquitoes and sterile females was that we brought the population down to zero within six months. </p>
<p>This is the first time that a population has been suppressed using a gene drive, albeit in the lab. </p>
<p>Gene drive is a <a href="https://www.nap.edu/catalog/23405/gene-drives-on-the-horizon-advancing-science-navigating-uncertainty-and">fast-moving and powerful genetic technology</a>. The ability to transform natural populations without constant human intervention, make them ideal to supplement the current tools and methods used to fight infectious diseases, and reduce their economic and ecological burden. </p>
<p>Even though the suppression of caged mosquito populations in the lab is a landmark achievement, an actual field release of a gene drive is at least a decade far in the future. </p>
<p>Because they can spread on their own, and over potentially large geographical areas, the technology raises potential ethical concerns over their use. For example, who decides when a gene drive is released if full consensus from the communities affected by it is not achieved? These issues are widely <a href="https://www.nature.com/articles/d41586-018-07436-4">debated</a> by scientists, ethicists, regulators and those who may be affected by the use of gene drive technology. </p>
<p>Nevertheless, the scientific community has made great progress over potential methods to <a href="https://www.nap.edu/catalog/23405">safeguard</a> the technology, including the potential for <a href="https://www.tandfonline.com/doi/full/10.1080/20477724.2018.1438880">designs</a> that would limit their spread. The final decision on whether a gene drive can be released in the wild must be made with the consent of the affected countries and more specifically the communities who live with these diseases every day.</p><img src="https://counter.theconversation.com/content/104613/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrea Crisanti receives funding from Bill and Melinda Gates Foundation, BBRC, DARPA</span></em></p><p class="fine-print"><em><span>Kyros Kyrou receives funding from the Bill & Melinda Gates Foundation and additionally from the BBSRC (BB/GCRF-IAA/10 and BB/GCRF-IAA/17/10) and DARPA (HR0011-17-2-0042). </span></em></p>Researchers are exploring genetic forms of population control called gene drives that spread traits faster that happens naturally. The goal is to curb mosquito-borne diseases like malaria.Andrea Crisanti, Professor of Molecular Parasitology, Imperial College LondonKyros Kyrou, PhD Student, Imperial College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1067752018-11-13T06:18:08Z2018-11-13T06:18:08ZWhat is Japanese encephalitis virus and how can I avoid it when I travel?<figure><img src="https://images.theconversation.com/files/245036/original/file-20181112-83579-1c5bszm.jpg?ixlib=rb-1.1.0&rect=24%2C131%2C1977%2C1174&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The mosquitoes that spread Japanese encephalitis are usually found in wetlands and drainage ditches, and will be out biting mostly at dawn and dusk.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/28ZFxTa">Bryon Lippincott/Flikr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>If you’re travelling to Asia, you’re probably mindful of the risks of malaria, dengue, or Zika. But authorities are warning Australians to take care to avoid another mosquito-borne disease, Japanese encephalitis, when holidaying in the region, after a <a href="https://www.news.com.au/travel/travel-updates/warnings/australians-warned-about-travelling-to-bali-amid-spike-in-japanese-encephalitis-cases/news-story/e255ca32f524bcbdae9d1ee1f7e3a429">spike in cases in Indonesia</a>.</p>
<p>Japanese encephalitic virus is part of the flavivirus family, which is also responsible for Zika, dengue and yellow fever.</p>
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Read more:
<a href="https://theconversation.com/zika-dengue-yellow-fever-what-are-flaviviruses-53969">Zika, dengue, yellow fever: what are flaviviruses?</a>
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<p>Japanese encephalitis occurs in <a href="https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-related-to-travel/japanese-encephalitis">Asia and parts of the western Pacific</a>, from Pakistan through to Papua New Guinea and north to Japan and parts of Russia. <a href="https://www.annualreviews.org/doi/full/10.1146/annurev.ento.54.110807.090510">Almost 200,000 cases are estimated to occur</a> each year.</p>
<p>Most people infected don’t suffer any symptoms. But around 1% of cases will result in severe illness. Symptoms include fever, headache and vomiting, which can progress to neurological complications, such as disorientation, seizures, and paralysis. </p>
<p>Of those who do suffer severe illness, almost one-third will die; while up to half of those who survive are left with long-term neurological impairment.</p>
<p>There is no specific treatment for the disease, but it can be prevented with a vaccine.</p>
<h2>How does it spread?</h2>
<p>The virus is maintained in nature between mosquitoes and waterbirds, mainly herons and egrets. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2630726/">Pigs are also an important host</a>, especially when they’re kept close to both people and sources of mosquitoes, such as rice paddies or other agricultural areas that use flood irrigation. Outbreaks are also more likely to occur during the monsoon season.</p>
<p>The mosquitoes that spread Japanese encephalitis virus are different to <em>Aedes aegypti</em> and <em>Aedes albopictus</em> – the mosquitoes that spread dengue, yellow fever and Zika viruses. These mosquitoes are active during the day and closely associated with small water-holding containers in urban areas.</p>
<p>The mosquitoes that transmit Japanese encephalitis virus, especially those belonging to the genus <em>Culex</em>, are usually found in wetlands and drainage ditches, and will be out biting mostly at dawn and dusk. </p>
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<img alt="" src="https://images.theconversation.com/files/245030/original/file-20181112-83582-fl72q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/245030/original/file-20181112-83582-fl72q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245030/original/file-20181112-83582-fl72q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245030/original/file-20181112-83582-fl72q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245030/original/file-20181112-83582-fl72q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245030/original/file-20181112-83582-fl72q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245030/original/file-20181112-83582-fl72q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The Culex group of mosquitoes plays an important role in spreading Japanese encephalitis virus.</span>
<span class="attribution"><span class="source">Stephen Doggett (NSW Health Pathology)</span></span>
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<h2>Is Australia at risk?</h2>
<p>Given outbreaks of Japanese encephalitis virus have occurred in Torres Strait and neighbouring Papua New Guinea, concern has been raised about the potential introduction and spread of the virus in Australia.</p>
<p>The virus has been detected in <a href="http://www.abc.net.au/catalyst/stories/s1097357.htm">sentinel pigs</a> and local mosquitoes from the <a href="https://www.ajtmh.org/content/journals/10.4269/ajtmh.2006.75.21">Cape York Peninsula</a>. These local mosquitoes have <a href="https://www.liebertpub.com/doi/abs/10.1089/vbz.2008.0037">the potential to spread</a> a number of closely related viruses. Both wild pigs and waterbirds are also common in northern Australia.</p>
<p>Fortunately, conditions don’t quite seem right for a local outbreak. </p>
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Read more:
<a href="https://theconversation.com/will-the-arrival-of-el-nino-mean-fewer-mosquitoes-this-summer-102496">Will the arrival of El Niño mean fewer mosquitoes this summer?</a>
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<p>Perhaps our local flaviviruses provide some immunity in local wildlife to infection with Japanese encephalitis virus. Research has shown that local mosquitoes may be more likely to bite local native wildlife (such as wallabies) than pigs, providing some <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2915.2003.00458.x">protection for Australia from local outbreaks</a>. </p>
<p>Genetic studies also suggest that local mosquitoes are not as efficient at spreading the virus <a href="https://bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-7-100">compared to those in countries to our north</a>. </p>
<p>While the risk of a local outbreak is low, Australian travellers should not be complacent.</p>
<h2>How can Australian travellers stay safe?</h2>
<p>There is a vaccine for Japanese encephalitis, but few travellers choose to have it, as they’re often told the risks are low unless they’re spending extensive time in rural or high-risk areas.</p>
<p>There is <a href="https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-related-to-travel/japanese-encephalitis">less than a one in a million</a> chance you may be infected during travel to a country that experiences regular outbreaks of the disease. But short trips aren’t entirely risk-free; travellers to Asia still need to take suitable precautions.</p>
<p>A study investigating 55 cases of international travellers becoming infected with Japanese encephalitis virus indicated that <a href="https://www.ajtmh.org/content/journals/10.4269/ajtmh.2010.09-0676">most spent over a month</a> at their destination but very few were vaccinated against the virus. </p>
<p>Given some uncertainty around the true levels of activity of Japanese encephalitis virus in some regions, there has been a <a href="https://link.springer.com/article/10.1007/s11908-018-0635-8">recent call to re-evaluate the recommendations</a>, which could result in more travellers getting vaccinated.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/245033/original/file-20181112-83564-1o5aboc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/245033/original/file-20181112-83564-1o5aboc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=365&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245033/original/file-20181112-83564-1o5aboc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=365&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245033/original/file-20181112-83564-1o5aboc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=365&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245033/original/file-20181112-83564-1o5aboc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=459&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245033/original/file-20181112-83564-1o5aboc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=459&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245033/original/file-20181112-83564-1o5aboc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=459&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Rice paddies can be a breeding ground for mosquitoes that spread Japanese encephalitis virus throughout Asia.</span>
<span class="attribution"><span class="source">From Flickr user sinta1</span></span>
</figcaption>
</figure>
<p>The reality is there is a far greater risk that you’ll be infected by <a href="https://theconversation.com/explainer-what-is-dengue-fever-8571">dengue</a> while <a href="https://link.springer.com/article/10.1007/s10096-011-1429-1">travelling in southeast Asia</a> than Japanese encephalitis virus. But in recent years, Australian travellers have been infected with Japanese encephalitis virus in <a href="https://www.abc.net.au/news/2017-06-21/australian-man-dies-after-returning-from-thailand/8639620">Thailand</a> and <a href="https://www.news.com.au/lifestyle/health/health-problems/melbourne-man-contracts-japanese-encephalitis-from-mosquito-bite-in-bali-loses-memory/news-story/9d16275d4f44142ae9a98a711f47d94a">Bali</a>.</p>
<p>Australian travellers heading to Indonesia are being reminded that, although the risk remains low, <a href="https://smartraveller.gov.au/countries/asia/south-east/pages/indonesia.aspx#health">precautions should be taken to avoid mosquito bites</a>, by:</p>
<ul>
<li><p>ensuring your accommodation is mosquito-proof (sleeping under a bed net may also help)</p></li>
<li><p>taking measures to avoid insect bites, including using insect repellent (and applying it regularly) and wearing long, loose-fitting, light-coloured clothing.</p></li>
</ul>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-best-and-worst-ways-to-beat-mosquito-bites-70274">The best (and worst) ways to beat mosquito bites</a>
</strong>
</em>
</p>
<hr>
<p>If you’re venturing out of holiday resorts to rural areas, consider vaccination as well. Even if you’re not, you can still get vaccinated before you go, but discuss this with your local doctor as part of your <a href="https://smartraveller.gov.au/guide/all-travellers/health/Pages/health-checks-and-vaccinations.aspx">pre-travel health checks</a>.</p>
<p>It only takes a single bite from an infected mosquito to transmit Japanese encephalitis virus and sometimes you can be in the wrong place at the wrong time.</p><img src="https://counter.theconversation.com/content/106775/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cameron Webb and the Department of Medical Entomology, NSW Health Pathology and University of Sydney, have been engaged by a wide range of insect repellent and insecticide manufacturers to provide testing of products and provide expert advice on mosquito biology. Cameron has also received funding from local, state and federal agencies to undertake research into mosquito-borne disease surveillance and management.</span></em></p><p class="fine-print"><em><span>Andrew van den Hurk has received funding from local, state and federal agencies to study the ecology of mosquito-borne pathogens, and their surveillance and control. He is an employee of the Department of Health, Queensland Government.</span></em></p>Japanese encephalitis virus is rare and doesn’t usually cause symptoms. But in a small proportion of cases it can result in long-term neurological impairment and death.Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of SydneyAndrew van den Hurk, Medical Entomologist, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1061332018-11-02T14:02:50Z2018-11-02T14:02:50ZPrenatal blood screening may predict Zika virus-associated fetal defects<figure><img src="https://images.theconversation.com/files/243532/original/file-20181101-83632-e9ou8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">These photos show mothers or family members holding infants born with microcephaly, one of many serious medical problems caused by congenital Zika syndrome.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/The-Week-That-Was-in-Latin-America-Photo-Gallery/85c344048add4b1093762419d8a22c69/80/0">AP Photo/Felipe Dana</a></span></figcaption></figure><p><em><a href="https://theconversation.com/zika-y-embarazo-analisis-de-sangre-prenatal-podria-predecir-malformaciones-fetales-106289">Leer en español</a></em>.</p>
<p>The sudden and rampant <a href="http://www.who.int/emergencies/zika-virus/en/">outbreak of Zika virus in 2016</a> terrified pregnant women, particularly those residing in Zika-endemic regions, such as Brazil, as well as those in the U.S. Their fear was justified given the link between Zika virus infection during pregnancy with having a small head, a condition known as microcephaly, and other congenital defects.</p>
<p>The absence of early prenatal diagnosis, or treatment, for birth defects has left thousands of <a href="https://www.cdc.gov/pregnancy/zika/data/pregwomen-uscases.html">mothers-to-be</a> worrying about their baby’s well-being. Others, meanwhile, have terminated their pregnancy rather than risk having a child with <a href="https://doi.org/10.1056/NEJMc1605389">birth defects</a>. </p>
<p><a href="http://uscmmi.com/jaejunglab/">Our research</a> revolves around mosquito-borne viruses such as Chikungunya virus and Zika virus. Each causes a distinct set of symptoms. Chikungunya virus produces debilitating persistent joint pain in adults and neurological symptoms in children; Zika virus causes defects in babies. In <a href="http://uscmmi.com/jaejunglab/">Jae Jung’s lab</a> at the University of Southern California, we are investigating the mechanisms that underlie the devastating consequences of these viral infections and developing new prenatal diagnostic tests to determine whether Zika babies are in good health.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/243523/original/file-20181101-83651-peb2ik.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243523/original/file-20181101-83651-peb2ik.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243523/original/file-20181101-83651-peb2ik.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243523/original/file-20181101-83651-peb2ik.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243523/original/file-20181101-83651-peb2ik.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243523/original/file-20181101-83651-peb2ik.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243523/original/file-20181101-83651-peb2ik.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A fellow student gently strokes Jose Wesley Campos, who was born with the Zika-caused microcephaly birth defect, at an early education daycare center in Bonito, Brazil.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Brazil-Zika-Kids-Boy-in-Bucket/fe3a773313b04610b33f237ac677bf9a/5/0">AP Photo/Eraldo Peres</a></span>
</figcaption>
</figure>
<h2>Zika and pregnancy</h2>
<p>Zika is the first mosquito-borne virus known to cause congenital defects. <em>Aedes aegypti</em>, one of the most invasive and widespread species of mosquito, is the primary vector for transmitting Zika. When healthy individuals, who are not pregnant, are infected with the Zika virus the infection often escapes notice because the <a href="https://www.cdc.gov/zika/symptoms/symptoms.html">symptoms are mild</a> or negligible. However, infection during the first and second trimester of pregnancy boosts the risk of miscarriages and diverse fetal defects such as <a href="https://doi.org/10.1056/NEJMoa1602412">eye abnormalities, neurological impairment</a> and in more severe cases, <a href="http://doi.org/10.1056/NEJMp1605367">microcephaly</a>.</p>
<p>Health workers try to assess the health of Zika babies using ultrasound during the second trimester or later. But it is difficult to see from these images whether the baby has developmental abnormalities. </p>
<p>On the other hand, fetal MRI captures high-resolution snapshots of the fetus. But this imaging technique can only be used in the second or third trimesters – when it is more difficult to terminate a pregnancy. A diagnostic assay that could detect abnormalities early in the pregnancy could alleviate the mother’s stress and make it easier to make swift reproductive decisions.</p>
<h2>Developing a new diagnostic test</h2>
<p>During the Zika outbreak in Brazil, there were other co-circulating mosquito-borne viruses such as Dengue virus and Chikungunya virus. So we also chose to take blood samples from women from the U.S. where these viruses are not endemic. <a href="https://doi.org/10.1172/jci.insight.124152">In our recent research</a>, we surveyed blood samples from 74 pregnant women: 30 were Zika-positive, 30 were negative and 14 were from women in Los Angeles. This study was led by <a href="http://uscmmi.com/jaejunglab/principal-investigator">Jae Jung</a>, in collaboration with <a href="https://portal.fiocruz.br/servico/laboratorio-de-doencas-febris-agudas">Patrícia Brasil</a> of the Instituto Nacional de Infectologia Evandro Chagas in Brazil, and <a href="https://www.uclahealth.org/karin-nielsen">Karin Nielsen-Saines</a> and <a href="https://www.mbi.ucla.edu/faculty/genhong-cheng/">Genhong Cheng</a> of UCLA.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/243520/original/file-20181101-83654-4aioi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243520/original/file-20181101-83654-4aioi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=469&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243520/original/file-20181101-83654-4aioi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=469&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243520/original/file-20181101-83654-4aioi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=469&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243520/original/file-20181101-83654-4aioi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=590&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243520/original/file-20181101-83654-4aioi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=590&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243520/original/file-20181101-83654-4aioi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=590&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A researcher in Jae Jung’s lab investigates brain defects in specimens of fetal tissue obtained from a Zika-infected patient.</span>
<span class="attribution"><span class="source">Weiqiang Chen</span></span>
</figcaption>
</figure>
<p>Our findings revealed an elevated production of 16 specific protein biomarkers, which are present in the blood of pregnant women who gave birth to babies with developmental delays and eye abnormalities. These biomarkers are potentially useful for predicting the outcomes of Zika pregnancies simply using blood specimens from the mother-to-be at any stage of pregnancy.</p>
<p>The number of Zika cases has dramatically declined following the major outbreaks in 2016. Yet, many Zika babies are still suffering from the dire consequences of prenatal infection. With the widespread abundance of <em>Aedes</em> mosquitoes, and the fact that Zika virus has not been eradicated, new outbreaks of Zika can occur anytime. </p>
<p>We are continuing our research to understand how Zika disrupts the development of the fetus, treatment strategies for babies affected by the virus, and ways to prevent Zika infection in the first place. Only when we have a thorough understanding of Zika infections can we assure the health of future generations.</p><img src="https://counter.theconversation.com/content/106133/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There is no vaccine or medicine for Zika. But researchers have identified factors in the blood that signal a fetus has Zika-related birth defects, helping mothers decide whether to terminate a pregnancy.Suan-Sin Foo, Postdoctoral scholar, University of Southern CaliforniaWeiqiang Chen, Postdoctoral scholar, University of Southern CaliforniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1050972018-10-22T10:41:48Z2018-10-22T10:41:48ZIs climate change causing a rise in the number of mosquito and tick-borne diseases?<figure><img src="https://images.theconversation.com/files/241473/original/file-20181019-105751-dgdmsr.jpg?ixlib=rb-1.1.0&rect=175%2C628%2C3589%2C1663&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Warmer temperatures could lead to more zones of the country that make good breeding sites for mosquitoes.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/mosquito-sucking-blood-on-human-skin-240718741">Apichart Meesri / Shutterstock.com</a></span></figcaption></figure><p>Life in a single-family home in suburban America, one with a quiet and spacious backyard, surrounded by natural habitats, lush green vegetation, where beautiful birds, squirrels and other small mammals come and go, is the American dream. Now, however, this once-cherished dream is being threatened by invading tick and mosquito species that are carrying emerging pathogens.</p>
<p>Public health officials use emerging vector-borne diseases (VBDs) in this context to refer to diseases or pathogenic agents transmitted by mosquitoes and ticks that have recently entered human populations for the first time. In some cases these diseases have historically been present in humans but have increased in frequency, geographic range or both. </p>
<p>Exposure to ticks and mosquitoes is the <a href="http://doi.org/10.1038/nature06536">single greatest risk factor for emerging vector borne diseases</a>, and the <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=PMC104807">introduction of these vectors to new geographic areas</a> has been a key contributing factor in the emergence of these diseases. Mounting evidence now suggests that climate change is facilitating the geographic expansion of mosquito and tick vectors of public health importance.</p>
<h2>New emerging vector-borne diseases in the US</h2>
<p>For more than half a century, outbreaks of dengue fever were not recorded in the continental United States. However, local infection has been recorded within the past decade in <a href="https://wwwnc.cdc.gov/eid/article/22/6/15-2000_article">Texas</a> and <a href="https://www.livescience.com/56304-dengue-case-in-florida.html">Florida</a>, a situation that has led to renewed interest in the <a href="https://www.ncbi.nlm.nih.gov/pubmed/23802440">threat posed by the mosquito vector <em>Aedes aegypti</em></a>. </p>
<p>In-depth studies of climate records over four decades reveal that sudden temperature changes were immediately followed by a <a href="http://doi.org/10.1016/j.vetpar.2009.09.011">corresponding increase in tick-borne encephalitis</a> in central and eastern Europe. The irregularly occurring <a href="https://www.climate.gov/enso">El Niño Southern Oscillation</a> which results from changes in air temperature over the Pacific Ocean that in turn cause changes in temperature and precipitation, has become a natural experiment for determining the effect of climate on infectious diseases. Previous studies of ENSO reveal that warmer temperatures and <a href="http://doi.org/10.1073/pnas.1604980113">extreme precipitation changes are associated with higher risk of tick-borne diseases</a> in the western United States. </p>
<p>This finding is particularly important, because climate change scenarios predict ENSO-like events to become more frequent. This is also exemplified by the <a href="http://doi.org/10.1016/S0140-6736(16)00256-7">recent global spread of Zika virus</a>, where extreme climatic conditions during one month in several parts of South America in 2015 were followed by the spread of Zika virus to that location the next month.</p>
<h2>Climate change and disease vectors</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/241478/original/file-20181019-105748-8wgaz5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/241478/original/file-20181019-105748-8wgaz5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/241478/original/file-20181019-105748-8wgaz5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/241478/original/file-20181019-105748-8wgaz5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/241478/original/file-20181019-105748-8wgaz5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/241478/original/file-20181019-105748-8wgaz5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/241478/original/file-20181019-105748-8wgaz5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Child with microcephaly is seen in a clinic that cares for people affected by congenital Zika syndrome.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/child-microcephaly-seen-entity-that-cares-645211522?src=qu2BkNJHPYl8YL2TMHE2jw-1-49">Joa Souza / Shutterstock.com</a></span>
</figcaption>
</figure>
<p>In theory, <a href="http://doi.org/10.1098/rstb2001.0894">as the climate changes mosquito and tick vectors adapt to new environments</a>, which lead to shifts in the spatial distribution, seasonality and incidence rates of disease-carrying mosquitoes and ticks as they move to different regions.</p>
<p>Climate change can shape the rates of emerging disease by various processes including a direct effect on mosquito and tick vectors, and <a href="http://doi.org/10.1371/journal.pntd.0005568">indirect effects on human vulnerability to emerging VBDs</a>. For example, warmer temperatures lead to longer breeding seasons and greater hatch rates, especially for mosquito populations. This will cause these vectors to seek more territory, which is also more readily available from warmer temperatures. </p>
<p>The environments characteristic of most suburban residential properties are enticing habitat for these vectors, which might explain why more ticks and human infections with emerging VBDs are <a href="http://doi.org/10.3201/eid2105.150150">increasingly</a> <a href="http://doi.org/10.3201/eid2102.141276">reported</a> <a href="http://doi.org/10.1056/NEJM197010152831607">from</a> residential areas. </p>
<p>Indirect effects of warmer temperatures include <a href="http://doi.org/10.1098/rspb.2017.0901">weakening human immune systems</a> after droughts or flooding, and disruptions to the health care system following disasters such as hurricanes and floods. Many scientists consider this indirect mechanism, where exceptional climatic conditions affect people’s behavior and increase exposure to vectors, to explain much of how climate change affects the spread of emerging VBDs.</p>
<h2>A word of caution</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/241476/original/file-20181019-105751-7udjti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/241476/original/file-20181019-105751-7udjti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/241476/original/file-20181019-105751-7udjti.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/241476/original/file-20181019-105751-7udjti.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/241476/original/file-20181019-105751-7udjti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/241476/original/file-20181019-105751-7udjti.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/241476/original/file-20181019-105751-7udjti.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ticks are present throughout the world, but they are especially fond of warm, humid climates.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tick-sign-flower-meadow-background-196724855?src=hRQvcwh3SyMVOIe0YpVc2w-1-27">Schlegelfotos / Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Although the evidence for associations between climate change and increased VBDs is strong, we should keep in mind that associations do not always indicate a causal link. In order to unequivocally attribute the changing distribution of mosquito and tick vectors of emerging VBDs to climate change, <a href="http://doi.org/10.1177/0141076814562718">scientific principles of causality must be established under randomized experimental conditions</a>. </p>
<p>For scientists to say definitively that climate change is directly boosting the population of disease-carrying mosquitoes and ticks, they would first need to demonstrate that the changes in distribution of these disease vectors were not due to other factors. </p>
<p>Why should we care about the association between climate change and the spread of emerging VBDs? For one, common bugs can transmit multiple pathogens. For example, the mosquito <em>Aedes aegypti</em> alone can spread <a href="https://theconversation.com/global-warming-to-expose-more-people-to-zika-spreading-mosquito-aedes-aegypti-58908">Zika virus</a>, dengue virus, chikungunya virus and yellow fever virus, while the tick <em>Ixodes scapularis</em> alone can transmit the causative agents of Lyme disease, anaplasmosis and babesiosis, among others. </p>
<p>Secondly, many of these diseases lead to increased health care costs, disability, and even death for affected individuals. </p>
<p>So far the current evidence suggests that while climate change is an important factor in the geographic and seasonal variation in mosquito- and tick-borne diseases, other factors including land-use patterns, socioeconomic and cultural factors, pest control, access to health care and human response to disease risk also play a role. </p>
<p>More rigorous long-term studies are needed to demonstrate unequivocally the impact of climate change on emerging VBDs of public health importance. If climate change increases the transmission of these diseases, we need to take all necessary steps to understand how this occurs with a view to preventing it. Otherwise, the American dream of home ownership in the suburbs is threatened, and climate change may soon be added to the long list of injustices and challenges that have undermined this American dream.</p><img src="https://counter.theconversation.com/content/105097/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Oghenekaro Omodior receives funding from Indiana University's Prepared for Environmental Change Grand Challenge Initiative. </span></em></p><p class="fine-print"><em><span>Daniel Becker receives funding from the Intelligence Community Postdoctoral Research Fellowship Program .</span></em></p>Is our changing climate making regions of the US more suitable for ticks and mosquitoes that spread diseases? Or is the climate changing human physiology making us more vulnerable?Oghenekaro Omodior, Assistant Professor of Recreation, Parks and Tourism, Indiana UniversityDaniel Becker, Postdoctoral Fellow, Indiana UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1031112018-09-16T06:29:46Z2018-09-16T06:29:46ZClimate change, water and the spread of diseases: connecting the dots differently<figure><img src="https://images.theconversation.com/files/236005/original/file-20180912-133880-4hoc6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Climate change also has an impact on public health.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/329474339?src=uWI_5Ss8htsMlQY2hG52Dw-1-30&size=medium_jpg">Shutterstock</a></span></figcaption></figure><p>Half a century ago concerns about climate change, environment vulnerability, population density and the sustainability of earth systems reached a broad audience. This was clear from books like the <a href="http://www.rachelcarson.org/SilentSpring.aspx">Silent Spring</a> published in 1962, and <a href="http://www.ask-force.org/web/Global-Warming/Meadows-Limits-to-Growth-Short-1972.pdf">The Limits to Growth</a> published 10 years later.</p>
<p>These works influenced environmental activism at the time. They also laid the foundations for growing <a href="http://www.pnas.org/content/115/33/8252">scientific</a> <a href="http://advances.sciencemag.org/content/3/5/e1600871">evidence</a> <a href="http://iopscience.iop.org/article/10.1088/1748-9326/aa6825">that climate change</a> was happening and was negatively affecting the earth.</p>
<p>But one piece of the puzzle has been missing: the impact of climate change on people, and specifically, on public health.</p>
<p>This changed at the beginning of this century with growing advocacy and gatherings such as the <a href="https://www.ncbi.nlm.nih.gov/m/pubmed/29610376/">Conference of Parties</a> and the publication of <a href="https://www.ecologyandsociety.org/vol14/iss2/art32/">new research</a>. Scientists began writing about the earth moving into a new era called the <a href="https://www.smithsonianmag.com/science-nature/what-is-the-anthropocene-and-are-we-in-it-164801414/">Anthropocene</a>. This is an era in which ecosystems were increasingly being affected by human behaviour, and in which people were being affected by the changes brought about by their actions. </p>
<p>The Anthropocene provided the impetus for renewed attention on health and sustainability for all species. This new understanding led to increasing new research, across disciplines, to new interdisciplinary journals, and to policy documents on the impact of climate change on health. Major new insights began to emerge. These included the fact that changes in weather patterns were affecting the behaviour of mosquitoes. This in turn was affecting our ability to control disease. A raft of work also started to emerge on the affects of changing weather patterns, heat waves, and access to clean water on people’s health. </p>
<p>The next step along this journey was that academics came to realise that they can’t work in disciplinary silos. For example, health scientists came to grasp that they need anthropologists, sociologists and economists for a full understanding of the impact of climate change. The circle of knowledge has, as a result, begun to expand.</p>
<p>Parallel to these efforts, artists and advocacy groups have worked to keep climate change on international and national policy agendas. For example, artists have taken inspiration and drawn from scientific research in engineering, chemistry, biology, and the earth sciences to make their art. In a first of its kind on the African continent, these efforts are reflected at a 10-day public and <a href="https://www.wits.ac.za/watershed/">academic programme</a> at the University of the Witwatersrand. The programme enmeshes art and science to provoke new thinking about water and how its politicisation affects public health.</p>
<h2>Insights from different disciplines</h2>
<p>Extreme weather events, shifts in temperature variation and precipitation, and higher mean temperatures have dramatically affected human health and well-being. </p>
<p>From a health perspective, incremental environmental changes over time have undone decades of investment in the control of infectious diseases. Many of these are water-borne and water-washed diseases, such as dysentery and scabies. They are result of poor personal hygiene because of inadequate water availability. These diseases, common throughout Africa, are often described as neglected diseases of poverty.</p>
<p>Scientists have started to explore the various affects in different settings in relation to different diseases. </p>
<p>For example, changes in temperature and rainfall have, in turn, changed the behaviour of vectors such as <a href="https://www.ncbi.nlm.nih.gov/pubmed/29274851">mosquitoes</a>, <a href="https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-018-3019-x">flies</a> and <a href="https://www.ncbi.nlm.nih.gov/pubmed/22142789">snails</a>, with other factors complicating the spread of disease (for a summary, <a href="https://idpjournal.biomedcentral.com/articles/10.1186/s40249-017-0378-z">see</a>). This means the settings that create the conditions for debilitating and potentially fatal diseases such as malaria, zika, and dengue have shifted. For example, mosquitoes have moved to new areas, introducing infection to previously unaffected people and certain animals.</p>
<p>Anthropologists have used a different lens to understand the impact. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2643480/">Research</a> shows that inequality influences people’s exposure to vector-borne diseases and other environmentally sensitive infections. <a href="https://www.cmcc.it/publications-type/referred-paper">Gender, class and age</a> have also emerged as points of vulnerability for disease and poor health in the context of climate change. </p>
<p>Climate change has, most notably, begun to affect weather patterns. Changes in precipitation and quantity, floods and droughts, and water insecurity are increasingly common as the planet warms. </p>
<p>Scientists have begun to track how this affects food production and other farming <a href="https://www.annualreviews.org/doi/abs/10.1146/annurev-environ-021810-094524">activities</a>. This in turn affects people’s livelihoods and food security. These changes are increasingly being followed not just by climate scientists, but also by academics from disciplines as wide-ranging as economics and politics. This follows the realisation that challenges of ageing infrastructure and water governance, for example, complicate finding solutions to overcoming the challenges posed by global warming.</p>
<h2>Creative interventions</h2>
<p>Scientists across disciplines – social, biological, and physical sciences as well as the humanities and arts – need to continue to work on ways to interrupt disease transmission in the context of global warming. They seek to identify appropriate interventions where climate change affects health – and to come up with creative solutions that cut across narrow paths of thinking.</p>
<p>Artists and civil society have a key role to play by creating narrative, visual and acoustic forms to support advocacy on issues of climate change, pollution, the ecology and environmental justice.</p><img src="https://counter.theconversation.com/content/103111/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lenore Manderson has received research funding from the Australian Research Council and more recently, the South African National Research Foundation. She has been an advisor to Special Programme for Research and Training in Tropical Diseases (TDR) for the past 30 years.</span></em></p>Scientists need to continue working across disciplines to find ways to disrupt disease transmission in the context of climate change.Lenore Manderson, Visiting Distinguished Professor of Environmental Studies, Brown University, USA, and Distinguished Professor, Public Health and Medical Anthropology, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1007192018-08-20T10:30:22Z2018-08-20T10:30:22ZGenetically modified mosquitoes may be best weapon for curbing disease transmission<figure><img src="https://images.theconversation.com/files/231765/original/file-20180813-2912-10016ka.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">More than 3.9 billion people live in regions where the Aedes aegypti mosquito is present. This species transmits Zika, dengue, chikungunya, and yellow fever.
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/mosquito-on-human-skin-sunset-200494427?src=hPItT4Sw3Cn291eDH36Amw-1-5">mycteria/Shutterstock.com</a></span></figcaption></figure><p>Mosquitoes are some of the most deadly creatures on the planet. They carry viruses, bacteria and parasites, which they transmit through bites, infecting some <a href="https://www.ebmedicine.net/topics.php?paction=showTopic&topic_id=405">700 million people and killing more than 1 million each year</a>. </p>
<p>With international travel, migration and climate change, these infections are no longer confined to tropical and subtropical developing countries. Pathogens such as West Nile virus and Zika virus have caused significant outbreaks in the United States and its territories that are likely to continue, with new invasive pathogens being discovered all the time. Currently, control of these diseases is mostly limited to broad-spectrum insecticide sprays, <a href="https://extension.psu.edu/potential-health-effects-of-pesticides">which can harm both humans and non-target animals and insects</a>. What if there was a way to control these devastating diseases without the environmental problems of widespread insecticide use?</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/231774/original/file-20180813-2915-1owb6a2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/231774/original/file-20180813-2915-1owb6a2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/231774/original/file-20180813-2915-1owb6a2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=405&fit=crop&dpr=1 600w, https://images.theconversation.com/files/231774/original/file-20180813-2915-1owb6a2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=405&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/231774/original/file-20180813-2915-1owb6a2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=405&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/231774/original/file-20180813-2915-1owb6a2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=509&fit=crop&dpr=1 754w, https://images.theconversation.com/files/231774/original/file-20180813-2915-1owb6a2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=509&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/231774/original/file-20180813-2915-1owb6a2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=509&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"><em>Aedes aegypti</em> mosquito larvae swim in a container at the Florida Mosquito Control District Office in Marathon, Fla. A study released in May 2017 suggests Zika began spreading in Florida mosquitoes about three months before infections showed up in the Miami area in the summer of 2016, and the virus likely was carried in by travelers from the Caribbean.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Zika-Florida/91cc1668742e45928ef2bc67aef56efe/18/0">Wilfredo Lee / AP Photo</a></span>
</figcaption>
</figure>
<p>Genetically modifying mosquitoes to prevent disease may sound like science fiction, but the technology has advanced in recent years to the point where this is no longer a scenario relegated to late-night movies. In fact, it’s not even a new idea; scientists were talking about modifying insect populations to control diseases as <a href="http://doi.org/10.3390/ijerph14091006">early as the 1940s</a>. Today, genetically modified (GM) mosquitoes, developed during the past <a href="http://www.pnas.org/content/95/7/3743.long">several</a> <a href="https://www.nature.com/articles/417452a">decades</a> of <a href="http://www.pnas.org/content/104/13/5580.long">research</a> in <a href="http://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1001003">university</a> <a href="http://www.pnas.org/content/112/49/E6736.long">laboratories</a>, are being used to combat mosquito-borne pathogens – including viruses such as dengue and Zika – in many locations around the globe, including the United States. Progress is also being made to use GM mosquitoes to combat malaria, the most devastating mosquito-borne disease, although field releases for malaria control have not yet taken place. </p>
<p>I have been working on GM mosquitoes, both as a lab tool and to combat disease, for over 20 years. During that time, I have personally witnessed the technology go from theoretical, to seeing it used in the field. I’ve seen <a href="http://doi.org/10.3390/ijerph14091006">older techniques</a> that were inefficient, random and slow pave the way for new methods like <a href="http://doi.org/10.1016/j.celrep.2015.03.009">CRISPR</a>, which enables efficient, rapid and precise editing of mosquito genomes, and <a href="http://www.nature.com/articles/s41467-018-05425-9">ReMOT Control</a> which eliminates the requirement for injecting materials into mosquito embryos. These new technologies make GM mosquitoes for disease control not a question of “if,” but rather a question of “where” and “when.” </p>
<p>Don’t worry, these genetic changes only affect the mosquitoes – they are not transmitted to people when the mosquito bites them. </p>
<h2>Ways to use genetically modified mosquitoes</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/231773/original/file-20180813-2924-1n9iixt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/231773/original/file-20180813-2924-1n9iixt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/231773/original/file-20180813-2924-1n9iixt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/231773/original/file-20180813-2924-1n9iixt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/231773/original/file-20180813-2924-1n9iixt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=530&fit=crop&dpr=1 754w, https://images.theconversation.com/files/231773/original/file-20180813-2924-1n9iixt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=530&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/231773/original/file-20180813-2924-1n9iixt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=530&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A worker sprays anti-mosquito fog in an attempt to control dengue fever at a neighborhood in Jakarta, Indonesia. Highly populated areas in the country are often hit with severe outbreaks of the mosquito-borne disease especially during the annual rainy season due to poor health services and unsanitary living conditions.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Indonesia-Daily-Life/85bc77e9a29747c588688c5391bd7159/3/0">Achmad Ibrahim / AP Photo</a></span>
</figcaption>
</figure>
<p>There are two alternative methods currently used to control mosquito-borne diseases using GM mosquitoes. The first is “population replacement” in which a mosquito population biologically able to transmit pathogens is “replaced” by one that is unable to transmit pathogens. This approach generally relies on a concept known as “gene drive” to spread the anti-pathogen genes. In gene drive, a genetic trait – a gene or group of genes – relies on a quirk on inheritance to spread to more than half of a mosquito’s offspring, boosting the frequency of the trait in the population.</p>
<p>The second approach is called “population suppression.” This strategy reduces mosquito populations so that there are fewer mosquitoes to pass on the <a href="http://doi.org/10.1371/journal.pntd.0000508">pathogen</a>. </p>
<p>While the concept of <a href="http://doi.org/10.1073/pnas.1521077112">gene drive in mosquitoes</a> is <a href="http://www.mdpi.com/1660-4601/14/9/1006">many decades old</a>, the gene-editing technique CRISPR has finally made it possible to easily engineer it in the laboratory. However, CRISPR-based gene drives have not yet been deployed in nature, mostly because they are still a new technology that lacks a firm international regulatory framework, but also due to problems related to the <a href="http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1006796">evolution of resistance</a> in mosquito populations that will stop the gene from spreading.</p>
<p>It may not be immediately obvious, but the gene in “gene drive” need not be a gene at all – it can be a microbe. All organisms exist not just with their own genomes, but also with the genomes of all their associated microbes – the “hologenome.” Spread of a microbial genome through a population by inheritance can also be thought of as gene drive. By this definition, the first gene drive that has been deployed in mosquito populations for disease control is a bacterial symbiont known as <em>Wolbachia</em>. <em>Wolbachia</em> is a bacterium that infects up to 70 percent of all known insect species, where it hijacks the insect reproduction to spread itself through the population. </p>
<p>Thus, the <em>Wolbachia</em> itself (with its genome of approximately 1,500 genes) acts as the genetic trait that is driven into the population. When <em>Wolbachia</em> is transferred into a previously uninfected mosquito, it often makes the mosquito more resistant to infection with pathogen that can cause disease in humans, such as multiple viruses (including <a href="https://www.nature.com/articles/nature10355">dengue</a> and <a href="https://www.sciencedirect.com/science/article/pii/S1931312816301573?via%3Dihub">Zika</a> viruses) and <a href="http://doi.org/10.1371/journal.ppat.1002043">malaria parasites</a>.</p>
<h2>A bacterium that fights disease</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/231775/original/file-20180813-2894-1rqbhre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/231775/original/file-20180813-2894-1rqbhre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=405&fit=crop&dpr=1 600w, https://images.theconversation.com/files/231775/original/file-20180813-2894-1rqbhre.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=405&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/231775/original/file-20180813-2894-1rqbhre.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=405&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/231775/original/file-20180813-2894-1rqbhre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=509&fit=crop&dpr=1 754w, https://images.theconversation.com/files/231775/original/file-20180813-2894-1rqbhre.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=509&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/231775/original/file-20180813-2894-1rqbhre.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=509&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Resident Annick Sternberg, left, releases <em>Wolbachia</em>-infected male mosquitoes, as Bill Petrie, director of Miami-Dade County Mosquito Control, center, looks on in South Miami, Fla., Feb. 8, 2018. Thousands of bacteria-infected mosquitoes are flying near Miami to test a new way to suppress insect populations that carry Zika and other viruses. At right is Patrick Kelly, field operations manager for Mosquito Mate.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Modified-Mosquitoes/d689afb66095432f857ac61123442f36/4/0">Lynne Sladky/AP Photo</a></span>
</figcaption>
</figure>
<p>In the last eight years, researchers have taken <em>Wolbachia</em> present in fruit flies and <a href="http://doi.org/10.1038/nature10356">transferred that bacteria into mosquitoes that transmit dengue virus.</a> Those modified insects were then released <a href="https://www.worldmosquitoprogram.org">in a dozen countries to control the disease</a>. Although marketed as a “non-GM strategy,” artificially infecting mosquitoes with <em>Wolbachia</em> clearly falls under the GM umbrella, as over 1,500 genes (the entire bacterial genome) have been transferred from the original fruit fly host into the mosquitoes. </p>
<p><a href="https://gatesopenresearch.org/articles/2-36/v1">Preliminary</a> dengue control results from these releases in Australia have been promising. However, control of the disease in other release areas with higher disease risk, such as South America and Asia, still needs to be determined, particularly as some <a href="http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0002965">studies</a> <a href="https://aem.asm.org/content/78/5/1491">have</a> <a href="http://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1004182">demonstrated</a> <a href="http://rspb.royalsocietypublishing.org/content/281/1779/20132837.long">that</a> <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0059619"><em>Wolbachia</em></a> can sometimes increase pathogen infection in mosquitoes rather than suppress it. </p>
<h2>GM mosquitoes that eliminate mosquitoes</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/232490/original/file-20180817-165934-1w65rx4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/232490/original/file-20180817-165934-1w65rx4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/232490/original/file-20180817-165934-1w65rx4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/232490/original/file-20180817-165934-1w65rx4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/232490/original/file-20180817-165934-1w65rx4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/232490/original/file-20180817-165934-1w65rx4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/232490/original/file-20180817-165934-1w65rx4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Estimated range of the dengue and Zika virus carrying mosquito species in the United States, <em>Aedes aegypti</em>, blue, and <em>Aedes albopictus</em>, red. States and territories where both species have been collected are purple. All U.S. states and territories except Alaska are at risk for West Nile virus.</span>
<span class="attribution"><span class="source">Jason Rasgon</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>The best current example of population suppression is the release of genetically modified sterile mosquitoes. This is a modern spin on the decades-old Sterile Insect Technique (SIT), where sterile male insects are released into natural populations to mate with the wild females, reducing the mosquito population. But, rather than crudely sterilizing mosquitoes with radiation or chemicals, clever genetic engineering is now used to sterilize them instead. The <a href="http://doi.org/10.1371/journal.pntd.0003864">company Oxitec has engineered mosquitoes with a gene that is lethal to females but not to males</a>, which do not bite or transmit disease. Thousands of these transgenic males are released into nature, where they mate with the wild females in the population. The genetic modification is inherited by the offspring of these matings; female offspring die, while male offspring, which carry the gene, survive and continue passing the trait to further generations. With fewer and fewer females the mosquito population is drastically suppressed. Oxitec has conducted releases in the <a href="https://www.caymancompass.com/2017/10/24/genetically-modified-mosquitoes-in-cayman-swat-wild-population/">Grand Caymans</a>, <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0042771">Malaysia</a>, <a href="http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0003864">Brazil</a>, and <a href="https://www.cnn.com/2017/04/20/health/florida-mosquito-wolbachia-trial-zika/index.html">Florida</a>.</p>
<p>There has been some opposition to these sterile mosquito releases, particularly in Florida. For example, in 2016, <a href="https://e360.yale.edu/features/genetically_modified_mosquito_sparks_a_controversy_in_florida">an Oxitec trial in the Florida Keys was met with some local resistance</a>. However, unlike gene drive strategies, release of sterile mosquitoes (genetically modified or not) has about the smallest environmental footprint and highest safety of any disease control strategy; certainly safer than broad-spectrum insecticide sprays. It is highly targeted, and thus if it works, will only result in elimination of the target mosquito species, which in this case (<em>Aedes aegypti</em>) is a highly invasive and non-native mosquito in Florida. </p>
<p>In addition to gene drive, <em>Wolbachia</em> bacteria have also been used for population suppression. Males infected with the bacteria are released into a mosquito population that is either not infected, or infected with a different <em>Wolbachia</em> strain, which leads to “incompatible” or sterile matings. This strategy again has a long history, and was <a href="http://doi.org/10.3390/ijerph14091006">first used to suppress mosquito populations</a> in the 1960s before people even knew that <em>Wolbachia</em> was causing certain populations of mosquitoes to be sterile when mated with one another. In current times, <a href="http://doi.org/10.1038/srep33846"><em>Wolbachia</em>-sterilized males have been released in multiple countries</a> including Australia and the U.S., in California and Florida, to control dengue virus.</p>
<p>In an increasingly interconnected world, and with the added problems of <a href="https://www.sciencedirect.com/science/article/pii/S1471492217302805?via%3Dihub">global climate change</a>, pathogens are not likely to stay confined to the developing world, but will be an increasing issue for the U.S. as well. With the evolution of insecticide resistance in mosquitoes a certainty, GM technology has the potential to reduce the burden of mosquito-borne diseases across the globe, without the environmental and health risks associated with harmful pesticide use. </p>
<p>Don’t be afraid if it sounds like science fiction; it may just save your life.</p><img src="https://counter.theconversation.com/content/100719/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jason Rasgon receives funding from the National Institutes of Health, and the National Science Foundation</span></em></p>For several billion people mosquitoes are more than a nuisance – they transmit deadly diseases. Now genetic modification may prove the most effective defense against the mosquito, preventing disease.Jason Rasgon, Professor of Entomology and Disease Epidemiology, Penn StateLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1012162018-08-14T10:31:03Z2018-08-14T10:31:03ZHow the media falls short in reporting epidemics<p>Lethal infectious diseases are making <a href="https://www.cnn.com/2018/08/07/world/dr-congos-health-ministry-reports-new-ebola-deaths-in-latest-outbreak/index.html">headlines</a> again, with <a href="http://www.who.int/ebola/situation-reports/drc-2018/en/">17 confirmed new Ebola cases</a> reported in Congo as of August 8. The news brings back the memories of Americans’ unjustified fear during <a href="https://www.bmj.com/content/349/bmj.g6712.full">the 2014 outbreak</a>. </p>
<p>In any outbreak or public health crisis, health organizations such as the Centers for Disease Control and Prevention need to deliver accurate and timely information to the public about risks and treatments. For most people, this information comes mainly from the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4254799/">news media</a>. </p>
<p>But does the news provide the information the public needs during outbreaks of infectious diseases? <a href="https://www.liebertpub.com/doi/abs/10.1089/hs.2017.0106">My study</a> suggests that probably not. Looking at the coverage of epidemics from the past few years, I found that the media often focused on what may have seemed interesting, but not what is necessary for people to make educated decisions. </p>
<h2>Communicating in a crisis</h2>
<p>In the late 1960s, backed by scientific developments in the form of antibiotics and vaccinations, health officials believed that humans had <a href="http://science.sciencemag.org/content/257/5073/1055">won the dreadful war against infectious diseases</a>. </p>
<p>Unfortunately, the declaration of victory over nature proved premature. <a href="https://www.cdc.gov/hiv/">New</a> viruses emerged and others <a href="https://med.stanford.edu/news/all-news/2017/07/small-drop-in-measles-vaccinations-would-have-outsized-effect.html">returned</a>, thanks to increased international travel, antibiotic resistance and decrease in immunity level.</p>
<p>During epidemics, <a href="https://emergency.cdc.gov/cerc/index.asp">the public needs to know</a> about the risks and ways to cope. <a href="http://www.latimes.com/science/sciencenow/la-sci-sn-disneyland-measles-under-vaccination-20150316-story.html">Individuals’ behavior</a> can impact an outbreak’s development. </p>
<p>For example, the Zika virus poses health risks such as <a href="https://www.cdc.gov/ncbddd/birthdefects/microcephaly.html">microcephaly</a>, a birth defect that affects the size of a fetus’s brain. The CDC’s communications about this virus described not only official projects such as a potential <a href="https://www.nytimes.com/2016/11/20/business/testing-the-limits-of-biotech-in-the-race-for-a-zika-vaccine.html?_r=0">Zika vaccine</a>, but also <a href="https://www.cdc.gov/zika/prevention/index.html">how individuals could reduce potential harm</a> by avoiding travel to infected areas and using mosquito repellents.</p>
<p>Information about the latest outbreaks and how to avoid or reduce harm is
abundant <a href="https://www.cdc.gov/vhf/ebola/index.html">on the CDC’s websites</a> and <a href="https://twitter.com/CDCgov">social media accounts</a>. The agency also sends out information to practitioners to <a href="https://www.cdc.gov/pregnancy/zika/family/communicating-with-provider.html">share with their patients</a>. </p>
<p>But most people don’t follow CDC’s Twitter account. In fact, almost half report learning about health issues from <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4197929/">nonmedical sources</a>, such as the news. </p>
<h2>What’s in the media</h2>
<p>I looked at <a href="https://www.liebertpub.com/doi/abs/10.1089/hs.2017.0106">over 5,000 news articles</a> from leading American newspapers such as The New York Times and Wall Street Journal. The dataset included all the articles published in these newspapers on three outbreaks from the last 10 years: swine flu, Ebola and Zika. </p>
<p>My goal was to examine the patterns of coverage: What types of information are prominent or absent in the coverage of infectious diseases? First, I used new techniques for automated analysis of big data to identify broad categories that were used in the coverage of epidemics. I analyzed the articles from each category to see whether they included information about risk and what can be done to reduce it.</p>
<p>My automated analysis identified three broad themes which I labeled based on manual content analysis: “scientific” information, focused on health risks and medical facts; “social” stories, dealing with the impact on markets, politics and cultural events; and a “pandemic” theme, focused on attempts to stop diseases abroad from entering the U.S.</p>
<p>Almost half of the coverage focused on the social consequences of diseases, such as their effect on the <a href="https://www.bbc.com/news/business-28865434">economy</a>, <a href="https://www.usatoday.com/story/news/world/2016/04/17/brazil-impeachment-vote-debate/83152146/">politicians</a> or <a href="http://www.sandiegouniontribune.com/sdut-swine-flu-sports-043009-2009apr30-story.html">athletes</a>. </p>
<p>What’s more, I found that articles tended to focus on only one theme at a time. For example, an article about the Rio Olympics tended to deal only with social aspects. </p>
<p>The fact that different articles focus on different aspects is not problematic by itself. People could still collect bits of information from different sources. But no matter which articles people read, there was a good chance for them to miss some important information. </p>
<p>On average, one in five articles analyzed included any practical information about steps individuals could take to avoid infection – for example, washing hands, avoiding travel or using repellents. Those that did were largely “scientific” articles. Only about one in eight “pandemic” articles included such information. None of the 120 “social” articles included practical information. </p>
<p>A core goal of any health communication is to give the audience <a href="http://psycnet.apa.org/record/1982-25814-001">a sense of control</a>. For that to happen, people should know that there are ways for them to protect against threats, and that <a href="https://www.sciencedirect.com/science/article/pii/074959789190020T">these ways are effective</a>. But as my analysis showed, news coverage, especially not articles from the “scientific” theme, tended to include very little amount of such information. </p>
<p>My study on the effects of media coverage is still ongoing, and it’s too early to reach definite conclusions. But my early analyses suggest that exposure to articles from the “social” category could lead to feelings of uncertainty, lack of perceived control and mistrust in health organizations. I found that providing audiences with articles that include information about risks and solutions, both individual and organizational, can improve people’s intention to comply with health recommendations during an epidemic.</p>
<h2>Rumors and misinformation</h2>
<p>Telling people about scary diseases without informing them about ways to protect themselves is a good way to cause <a href="https://emergency.cdc.gov/cerc/ppt/CERC_Psychology_of_a_Crisis.pdf">anxiety and emotional distress</a> – and a bad way to build <a href="https://www.ncbi.nlm.nih.gov/pubmed/11419589">trust in government health agencies</a>.</p>
<p>During an outbreak, in the absence of accurate information, people may look to alternative sources that are <a href="https://www.bmj.com/content/349/bmj.g6178.full">dangerously misleading</a> – saying, for example, that Ebola can be cured using plants and herbs. That can lead to a range of unwanted <a href="https://academic.oup.com/jpubhealth/advance-article/doi/10.1093/pubmed/fdy042/4925540">outcomes</a>, including <a href="http://www.cnn.com/2014/10/20/health/ebola-overreaction/index.html">unjustified panic</a>. One CNN commentator dubbed Americans’ outsize reactions to the threat of ebola “Fear-bola.”</p>
<p>In my view, it would be ideal if all news articles on outbreaks at least briefly mentioned or linked readers to practical information, even when discussing the nonmedical aspects of the disease. </p>
<p>But, since changing journalistic routines is probably difficult, it’s up to health organizations and the public to fill the gaps. I hope that my work would encourage CDC and other organizations to compensate for the gaps in news coverage through their own direct communications with the public. </p>
<p>But I also believe that the public would benefit from understanding how the media works during outbreaks. People should complement what they learn from the news with occasional visits to official websites and social media channels. It’s never too early to start.</p><img src="https://counter.theconversation.com/content/101216/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Yotam Ophir received funding for the discussed study from the Annenberg School for Communication at the University of Pennsylvania. </span></em></p>A study of recent epidemics like Zika and Ebola suggests that the media may fail to tell the public what to do during an outbreak.Yotam Ophir, Postdoctoral Fellow in Science Communication at the Annenberg Public Policy Center, University of PennsylvaniaLicensed as Creative Commons – attribution, no derivatives.