tag:theconversation.com,2011:/fr/topics/yellow-fever-10866/articlesYellow fever – 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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Read more:
<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/2015692023-04-18T20:01:07Z2023-04-18T20:01:07ZDiseases gave us the rise of Christianity, the end of the Aztecs and public sanitation. How might future plagues change human history?<figure><img src="https://images.theconversation.com/files/517613/original/file-20230327-27-ualse4.jpg?ixlib=rb-1.1.0&rect=0%2C6%2C4439%2C3183&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Elena Mozhvilo/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>“Every once in a while a book lands on your desk that changes the way you perceive the world you live in, a book that fundamentally challenges your understanding of human history.” So began the blurb that came with this book. Aha! I thought. The usual advertising hyperbole, a gross exaggeration. </p>
<p>Yet <a href="https://www.penguin.com.au/books/pathogenesis-9781911709053">Pathogenesis</a> <em>did</em> challenge much of my understanding of world history. Who knew that if it wasn’t for an Ebola-like pandemic in the 2nd century CE, Christianity would never have become a world religion? Or that if it weren’t for retroviruses, women would be laying eggs rather than having live births? (According to the book’s author, a retrovirus inserted DNA into our ancestor’s genome that caused the placenta to develop.)</p>
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<p><em>Book review: Pathogenesis: How germs made history – by Jonathan Kennedy (Torva)</em></p>
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<p>However, this is not another book of Amazing Facts: it is a work of scholarship, with nearly 700 references and notes. At the same time, it is very readable, and even amusing at times. </p>
<p>Many books have been written about the impact of disease on civilisation. I have even written my own modest <a href="https://medium.com/@adrian.esterman/infectious-diseases-and-their-impact-on-civilisation-4eb8ac72cc5b">essay</a> on the topic. However,
Pathogenesis delves deeply into the social history of the world. </p>
<p>Jonathan Kennedy has a PhD in sociology from the University of Cambridge, and his sociological bent comes through strongly. In eight chapters, and some 350 pages, Kennedy takes us on a whirlwind tour of social history, describing how infectious diseases have shaped humanity at every stage. </p>
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Read more:
<a href="https://theconversation.com/viruses-are-both-the-villains-and-heroes-of-life-as-we-know-it-169131">Viruses are both the villains and heroes of life as we know it</a>
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<h2>‘It’s a bacterial world’</h2>
<p>Kennedy starts by describing the three great branches of living organisms, <a href="https://theconversation.com/from-peaceful-coexistence-to-potential-peril-the-bacteria-that-live-in-and-on-us-104110">bacteria</a>, <a href="https://microbiologysociety.org/why-microbiology-matters/what-is-microbiology/archaea.html">archaea</a>, and <a href="https://www.britannica.com/science/eukaryote">eukaryotes</a> – it is the latter that contains all complex life forms, including humans. However, fewer than 0.001% of all species are eukaryotes. </p>
<p>Bacteria, on the other hand, are the dominant life form on this planet. As Kennedy puts it, “it’s a bacterial world, and we’re just squatting here”. </p>
<p>Our own species, <em><a href="https://theconversation.com/rethinking-homo-sapiens-the-story-of-our-origins-gets-dizzyingly-complicated-99760">Homo sapiens</a></em>, arose some 315,000 years ago, living for the most part in Africa. At the same time, human species such as Neanderthals and <a href="https://theconversation.com/dna-from-elusive-human-relatives-the-denisovans-has-left-a-curious-mark-on-modern-people-in-new-guinea-196113">Denisovans</a> spread out into Europe. However, about 50,000 years ago, <em>Homo sapiens</em> burst out of Africa and spread across the world, while all other human species simply vanished. There are many <a href="https://www.scientificamerican.com/article/how-homo-sapiens-became-the-ultimate-invasive-species/">theories</a> as to why and how this occurred – for example, perhaps <em>Homo sapiens</em> were just smarter. </p>
<p>However, Kennedy proposes his own theory. Because <em>Homo sapiens</em> lived primarily in Africa, they were exposed to many pathogens, and eventually acquired genetic changes that gave them some protection. The exodus out of Africa exposed other species to these pathogens, causing their demise. </p>
<p>He describes the <a href="https://theconversation.com/who-were-the-mysterious-neolithic-people-that-enabled-the-rise-of-ancient-egypt-heres-what-weve-learned-on-our-digs-121070">Neolithic</a> revolution, which took place about 12,000 years ago and which saw the change from hunter-gatherers to farmers. Because of their nomadic existence in small groups, hunter-gatherers tended to be relatively healthy, with an average lifespan of 72 - better than the average lifespan in some countries today! </p>
<p>It has always been assumed that this revolution was a good thing, bringing better nutrition and more leisure time. However, in Kennedy’s view, the Neolithic revolution led to the emergence of despotism, inequality, poverty and backbreaking work. He describes how settlement and the farming of domestic animals led to the emergence of zoonotic diseases – that is, <a href="https://theconversation.com/preventing-future-pandemics-starts-with-recognizing-links-between-human-and-animal-health-167617">diseases spread by animals</a>. </p>
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<span class="caption">Settlement and the farming of domestic animals led to the emergence of diseases spread by animals.</span>
<span class="attribution"><span class="source">kallerna/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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Read more:
<a href="https://theconversation.com/disease-evolution-our-long-history-of-fighting-viruses-54569">Disease evolution: our long history of fighting viruses</a>
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<h2>Plagues and social upheavals</h2>
<p>In a chapter on ancient plagues, Kennedy quotes from Monty Python’s <a href="https://theconversation.com/life-of-brian-at-40-an-assertion-of-individual-freedom-that-still-resonates-114743">The Life of Brian</a>: </p>
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<p>All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us?</p>
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<p>He points out that Roman cities were, in fact, “filthy, stinking and disease-ridden”, and goes on to describe the great plagues <a href="https://theconversation.com/how-3-prior-pandemics-triggered-massive-societal-shifts-146467">that weakened the Roman Empire</a>. The first was the Antonine Plague, possibly caused by smallpox. This was followed some 70 years later by the Plague of Cyprian from AD 249-262, which led to the splitting of the Roman Empire and the rise of Christianity. </p>
<p>Kennedy completes this chapter with a description of the Plague of Justinian, caused by bubonic plague. The massive deaths caused by this epidemic led to the demise of the Roman Empire, and the Muslim conquest of the Middle East. </p>
<p>In the period 1346–53, the <a href="https://theconversation.com/did-the-black-death-give-birth-to-modern-plagues-3820">Black Death</a> tore through North Africa and Europe, killing an <a href="https://en.wikipedia.org/wiki/Black_Death">estimated</a> 75 million to 200 million people. Kennedy describes the devastation and huge social upheavals that resulted from this pandemic. Until then, the Roman Catholic Church dominated society. But:</p>
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<p>During the Black Death and subsequent plague outbreaks, people looked to the Church for comfort. All too often they didn’t find it. </p>
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<span class="caption">The Black Death killed an estimated 75–200 million people in Europe and North Africa. Hugo Simberg Black Death.</span>
<span class="attribution"><span class="source">Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>This led to the rise of Protestantism, aided by the invention of the printing press - a shortage of labour encouraged the development of such labour-saving devices. Over the next 200 years, waves of plague repeatedly hit Europe. A quarantine system was developed in Venice, and <em>cordon sanitaires</em> established, to prevent movement of people between cities - ring any bells? </p>
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Read more:
<a href="https://theconversation.com/did-the-black-death-give-birth-to-modern-plagues-3820">Did the Black Death give birth to modern plagues?</a>
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<h2>Pathogens as New World killers</h2>
<p>In the period from 1500 onwards, white colonialists nearly wiped out indigenous people by infecting them. Kennedy starts with the early 16th century, when Spanish conquistador Hernán Cortés led an expedition to Mexico. His arrival <a href="https://theconversation.com/how-smallpox-devastated-the-aztecs-and-helped-spain-conquer-an-american-civilization-500-years-ago-111579">introduced smallpox</a>, which resulted in the total destruction of the Aztec Empire within just two years. However, this was just the start. </p>
<p>In the early 1530s, Mexico was hit by an epidemic of <a href="https://theconversation.com/measles-new-efforts-needed-to-stop-an-old-disease-13706">measles</a> that killed 80% of its population, making it the deadliest epidemic in recorded history. Over the following decades, across the whole of the Americas, the introduction of infectious diseases from Europe resulted in a 90% fall in the population. </p>
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<a href="https://images.theconversation.com/files/517624/original/file-20230327-15-s0x2ks.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/517624/original/file-20230327-15-s0x2ks.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/517624/original/file-20230327-15-s0x2ks.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=441&fit=crop&dpr=1 600w, https://images.theconversation.com/files/517624/original/file-20230327-15-s0x2ks.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=441&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/517624/original/file-20230327-15-s0x2ks.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=441&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/517624/original/file-20230327-15-s0x2ks.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=554&fit=crop&dpr=1 754w, https://images.theconversation.com/files/517624/original/file-20230327-15-s0x2ks.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=554&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/517624/original/file-20230327-15-s0x2ks.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=554&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Hernán Cortés brought smallpox to Mexico, resulting in the total destruction of the Aztec Empire within two years, as illustrated in this 16th-century drawing of Aztec smallpox victims.</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
</figcaption>
</figure>
<p>However, during this period, it wasn’t just the New World that was profoundly affected by pathogens. On the west coast of Africa, explorers and would-be colonialists died in droves from <a href="https://theconversation.com/worlds-first-mass-malaria-vaccine-rollout-could-prevent-thousands-of-children-dying-169457">malaria</a> and <a href="https://theconversation.com/zika-dengue-yellow-fever-what-are-flaviviruses-53969">yellow fever</a>. </p>
<p>Interestingly, Kennedy starts his chapter on revolutionary plagues with the murder of <a href="https://theconversation.com/george-floyd-deserved-a-better-life-a-new-book-charts-his-trajectory-from-poverty-to-the-us-prison-industrial-complex-and-the-impact-of-his-death-182947">George Floyd</a> and the <a href="https://theconversation.com/the-black-lives-matter-movement-has-provoked-a-cultural-reckoning-about-how-black-stories-are-told-149544">Black Lives Matter</a> movement, before delving deep into the history of slavery. He describes slavery in Greek and Roman times, and the booming trade in slaves in the medieval Mediterranean. </p>
<p>The association between black Africans and <a href="https://theconversation.com/slavery-is-not-a-crime-in-almost-half-the-countries-of-the-world-new-research-115596">slavery</a> only began in the 15th century. In fact, only 3% of the 12.5 million humans trafficked across the Atlantic ended up in the United States. The most common destinations of the slave ships were the European colonies in the Caribbean, where African slave labour was first used more than a century before their shipment to North America. </p>
<p>Meanwhile, in the Caribbean, slave labour from tropical West Africa toiled on sugar plantations owned by the English, Spanish, French and Dutch. Yellow fever carried by mosquitoes wiped out many of the Europeans, including military garrisons, leading to slave revolts.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/friday-essay-a-slave-state-how-blackbirding-in-colonial-australia-created-a-legacy-of-racism-187782">Friday essay: a slave state - how blackbirding in colonial Australia created a legacy of racism</a>
</strong>
</em>
</p>
<hr>
<h2>Diseases ‘thrived’ in Dickensian habitats</h2>
<p>When Kennedy switches his focus to Britain, and the industrial revolution, he describes it as the change from a Thomas Hardy novel to one by <a href="https://theconversation.com/great-expectations-by-charles-dickens-class-prejudices-the-convict-stain-and-a-corpse-bride-159816">Charles Dickens</a>. The crowded and unsanitary conditions in working-class urban districts created new habitats, in which pathogens thrived. </p>
<p>Kennedy again evokes Monty Python to invoke the scenery of those days, reminding readers of the famous four Yorkshiremen sketch. The scene made me think of a different quote from the same sketch:</p>
<blockquote>
<p>You were lucky to have a house! We used to live in one room, all hundred and twenty-six of us, no furniture. Half the floor was missing; we were all huddled together in one corner for fear of falling!</p>
</blockquote>
<p>Every Epidemiology 101 course covers the story of <a href="https://www.newscientist.com/people/john-snow/">John Snow</a> (no – not the “Winter is coming” one!). <a href="https://www.cdc.gov/csels/dsepd/ss1978/lesson1/section2.html">Two decades</a> before the development of the microscope, Snow examined cholera outbreaks to discover the cause of disease and how to prevent it. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/517625/original/file-20230327-14-jix57.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/517625/original/file-20230327-14-jix57.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/517625/original/file-20230327-14-jix57.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=619&fit=crop&dpr=1 600w, https://images.theconversation.com/files/517625/original/file-20230327-14-jix57.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=619&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/517625/original/file-20230327-14-jix57.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=619&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/517625/original/file-20230327-14-jix57.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=778&fit=crop&dpr=1 754w, https://images.theconversation.com/files/517625/original/file-20230327-14-jix57.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=778&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/517625/original/file-20230327-14-jix57.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=778&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">John Snow proved in 1854 that cholera is a waterborne disease: a London pub is named for him.</span>
<span class="attribution"><a class="source" href="https://www.geograph.org.uk/profile/6699">ceridwen/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>During the third UK cholera outbreak in 1854, Snow famously removed London’s Broad Street water pump, to demonstrate that cholera was a waterborne disease. For those interested, there is a <a href="https://londonspubswherehistoryreallyhappened.wordpress.com/2019/03/05/john-snow/">John Snow</a> pub in London. Kennedy, of course, includes this story in his book.</p>
<p>Kennedy points out that 3.5 billion people – half of the world’s population – have no access to proper toilets, while a billion don’t have clean drinking water and 1.5 million people, mainly children, die every year from waterborne diarrhoeal diseases. </p>
<p>We still have massive <a href="https://theconversation.com/explainer-why-cholera-remains-a-public-health-threat-74444">cholera outbreaks</a>, especially in areas where normal life has been disrupted by war or natural disasters. <a href="https://theconversation.com/tuberculosis-kills-as-many-people-each-year-as-covid-19-its-time-we-found-a-better-vaccine-151590">Tuberculosis</a> still kills 1.2 million people a year, despite the availability of antibiotics. Malaria kills another 600,000. </p>
<p>Finally in this section, he briefly covers <a href="https://theconversation.com/covid-hospitalisations-and-deaths-are-rising-faster-than-cases-but-that-doesnt-mean-more-severe-disease-187163">COVID</a>. He points out that not everyone in the world benefited from the medical advances that came about because of COVID, and the self-interested actions of high-income countries have deprived the poorer countries. As he puts it, “pathogens thrive on inequality and injustice”. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fleas-to-flu-to-coronavirus-how-death-ships-spread-disease-through-the-ages-137061">Fleas to flu to coronavirus: how 'death ships' spread disease through the ages</a>
</strong>
</em>
</p>
<hr>
<h2>Future plagues</h2>
<p>Kennedy concludes by looking at future plagues. He points out humanity’s precarious position: we live on a planet dominated by bacteria and viruses. He believes our best chance of surviving the threat posed by pathogens will come from working collaboratively and reducing inequality both within and between countries. </p>
<p>Based on its title, I assumed this book would be about the role of pathogens in shaping civilisation. Instead, I found a social history of the world, with the odd foray into diseases and their influence on society. Nonetheless, I thoroughly enjoyed the book, and can highly recommend it to those with an interest in history, sociology and epidemiology.</p><img src="https://counter.theconversation.com/content/201569/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adrian Esterman 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>This whirlwind tour of social history describes how infectious diseases have shaped humanity at every stage. It suggests reducing inequality will give us our best chance of surviving future plagues.Adrian Esterman, Professor of Biostatistics and Epidemiology, University of South AustraliaLicensed 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">
<figcaption>
<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>
</figcaption>
</figure>
<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/1855472022-06-22T14:53:07Z2022-06-22T14:53:07ZAt what point is a disease deemed to be a global threat? Here’s the answer<figure><img src="https://images.theconversation.com/files/470226/original/file-20220622-23-p5dnh3.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">Shutterstock</span></span></figcaption></figure><p>Whenever there is an outbreak of a disease in the world – such as <a href="https://theconversation.com/monkeypox-this-is-an-entirely-new-spread-of-the-disease-184085">monkeypox</a> – it is up to the World Health Organization (WHO) to consider what sort of weight to give it, including whether or not it constitutes a public health emergency of international concern.</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>. 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.</p>
<p>There are many diseases that can affect large numbers of people. But not all diseases are considered public health emergencies.</p>
<p>The <a href="https://theconversation.com/whats-the-difference-between-pandemic-epidemic-and-outbreak-133048">seriousness of an epidemic</a> is a function of several factors.</p>
<p>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 (it’s more serious if there are none), impact on travel and trade, and the socioeconomic context.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-the-drc-ebola-outbreak-was-declared-a-global-emergency-and-why-it-matters-121991">Why the DRC Ebola outbreak was declared a global emergency and why it matters</a>
</strong>
</em>
</p>
<hr>
<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 effects of epidemic diseases across borders, as well as concern about undue interference with trade.</p>
<p>In 1969 the regulations were <a href="https://africacdc.org/download/international-health-regulations/#:%7E:text=The%201969%20Regulations%2C%20which%20initially,the%20global%20eradication%20of%20smallpox.">renamed</a> the “International Health Regulations” by the WHO. 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 minimum interference with world traffic.</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 incorporation of human rights 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>
<h2>More than a health issue</h2>
<p>But the regulations can only go so far. Many countries cannot comply with them due to lack of resources.</p>
<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. During COVID-19 we also saw civil unrest in some countries. All of these issues are considerations for the WHO when deciding whether to declare a public health emergency of international concern.</p>
<p><em>This is a revised extract from an article <a href="https://theconversation.com/why-the-drc-ebola-outbreak-was-declared-a-global-emergency-and-why-it-matters-121991">previously published</a> by The Conversation Africa written by C Raina MacIntyre and Obijiofor Aginam.</em></p><img src="https://counter.theconversation.com/content/185547/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>C Raina MacIntyre has consulted for or been on advisory boards in the last year for Sanofi, GSK, Bavarian Nordic. She is on the WHO COVID-19 Vaccine Composition Technical Advisory Group and the WHO SAGE Ad Hoc Working Group on Smallpox and Monkeypox. She receives funding from NHMRC and MRFF. </span></em></p><p class="fine-print"><em><span>Obijiofor Aginam 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 seriousness of an epidemic is a function of several factors, including the degree of contagiousness and potential for rapid spread.C Raina MacIntyre, Professor of Global Biosecurity, NHMRC Principal Research Fellow, Head, Biosecurity Program, Kirby Institute, UNSW SydneyObijiofor Aginam, Principal Visiting Fellow & Former Deputy Director, International Institute for Global Health (UNU-IIGH), United Nations UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1794352022-03-20T09:23:50Z2022-03-20T09:23:50ZKenya has a yellow fever outbreak: how to deal with it<figure><img src="https://images.theconversation.com/files/452597/original/file-20220316-8340-hoh886.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A river flows through Nairobi's Kibera slum. Communities should be engaged in environmental management to reduce mosquito breeding sites.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/river-in-kibera-slum-nairobi-kenya-royalty-free-image/1128064520?adppopup=true">Getty Images</a></span></figcaption></figure><p>On 5 March 2022, Kenya declared an outbreak of yellow fever in Isiolo County after the death of three people. More than 20 people were <a href="https://nation.africa/kenya/counties/isiolo/kenya-declares-yellow-fever-outbreak-after-three-die-in-isiolo-3738010">reported</a> to have contracted the deadly viral disease in Isiolo in the previous month. Counties bordering Isiolo were placed in the high-risk bracket. </p>
<p>Yellow fever <a href="https://www.who.int/emergencies/disease-outbreak-news/item/yellow-fever---west-and-central-africa#:%7E:text=In%202021%2C%20nine%20countries%20in,for%20the%20disease%20and%20have">outbreaks</a> occurred in nine African countries in 2021. They were Cameroon, Chad, Central African Republic, Côte d'Ivoire, the Democratic Republic of Congo, Ghana, Niger, Nigeria and the Republic of Congo. </p>
<p>It is <a href="https://www.who.int/news-room/questions-and-answers/item/yellow-fever">estimated</a> that 47 countries in the world – 34 in Africa and 13 in Central and South America – are susceptible to yellow fever. The disease is <a href="https://www.cdc.gov/csels/dsepd/ss1978/lesson1/section11.html">endemic</a> in tropical areas of these regions. </p>
<p>In Africa, the <a href="https://www.afro.who.int/health-topics/yellow-fever">burden</a> was estimated in 2013 to be between 84,000 and 170,000 severe cases and 29,000 to 60,000 deaths. Most of the world’s yellow fever cases have been reported in west and east Africa. </p>
<h2>Transmission and symptoms</h2>
<p>Yellow fever is an acute viral haemorrhagic disease which is <a href="https://www.cdc.gov/yellowfever/transmission/index.html">transmitted</a> by infected mosquitoes. It is also possible to contract the disease from the bite of an infected primate or human. </p>
<p>The symptoms of yellow fever range from mild, nonspecific illness (fever, headache, muscle pain, nausea, vomiting and fatigue) to severe disease (jaundice, haemorrhage and death). The severe symptoms are usually recorded in only a small proportion of patients, but death can occur in half of these cases within 10 days. </p>
<p>According to the World Health Organisation, <a href="https://www.who.int/news-room/fact-sheets/detail/yellow-fever">three types</a> of yellow fever virus transmission may occur in Africa. </p>
<ul>
<li><p>The first is the sylvatic (jungle) transmission, which is rare but endemic. It is caused by <em>Aedes africanus</em> mosquitoes feeding on primates like monkeys and humans found around forests at night. </p></li>
<li><p>The second is intermediate transmission. This is the commonest in Africa. It is driven by mosquito species like <em>Aedes formosus, Aedes africanus</em> and <em>Aedes simpsoni</em> which breed in the wild and around households. Exposure of one person can lead to infection of all household members. </p></li>
<li><p>Lastly, there is urban or large endemic transmission. This occurs when infected people introduce the yellow fever virus into densely populated areas that are infested with <em>Aedes aegypti</em> mosquitoes, and where most people have little or no immunity because they haven’t been vaccinated or previously exposed to the disease. </p></li>
</ul>
<h2>Vaccine</h2>
<p>There is no specific anti-viral drug for yellow fever at the moment but the disease is preventable through a single dose <a href="https://www.cdc.gov/yellowfever/vaccine/index.html">vaccine</a>. The vaccine provides a sustained immunity and lifelong protection for 80% to 100% of vaccinated people. At the moment, Kenya doesn’t have a regular vaccination programme for risk areas but the government usually arranges for mass vaccinations during outbreaks.</p>
<p>Infants of less than nine months, pregnant women (except during a yellow fever outbreak), people with egg protein allergies, and those with low immunity should not be vaccinated.</p>
<h2>Risk in Kenya</h2>
<p>Before the current outbreak in Kenya, yellow fever infected 55 people and killed 34 in Kerio valley in 1992 and 1993. That outbreak came 50 years after two reported cases in 1943. </p>
<p><a href="https://www.researchgate.net/publication/13496835_First_recorded_outbreak_of_yellow_fever_in_Kenya_1992-1993_II_Entomologic_investigations">Studies</a> have showed that the 1992/93 outbreak was sylvatic, transmitted mainly by <em>Aedes africanus</em> and <em>Aedes keniensis</em> mosquitoes. The outbreak, like the current one, predominantly affected young males. The victims had exposure to woodlands where vervet monkeys and baboons were found.</p>
<p>Increased population density in the rural areas that may lead to encroachment into forest lands has been <a href="https://www.researchgate.net/publication/13496834_First_recorded_outbreak_of_yellow_fever_in_Kenya_1992-1993_I_Epidemiologic_investigations">suggested</a> as a risk factor in Kenya. This, coupled with rapid migration to the densely populated cities – where high densities of <em>Aedes aegypti</em> mosquitoes coexist with unvaccinated residents – provides the conditions for an epidemic. </p>
<p>No yellow fever outbreak has ever been reported in a Kenyan city, but the risk should not be ignored. Most urban areas in Kenya are <a href="https://www.weforum.org/agenda/2018/06/Africa-urbanization-cities-double-population-2050-4%20ways-thrive/">crowded</a> with unvaccinated people. </p>
<p>The urban centres are also plagued with poor housing, inadequate sanitation and little access to running water. Water is often stored in large, open containers. These are the preferred breeding sites for mosquitoes that transmit yellow fever in urban areas. Recent <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(16)30513-8/fulltext">reports</a> from Angola and Congo indicate that yellow fever epidemics may spread quickly in crowded urban areas.</p>
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<strong>
Read more:
<a href="https://theconversation.com/lockdown-and-flooding-raise-the-risk-of-a-spike-in-mosquito-borne-diseases-in-kenya-139129">Lockdown and flooding raise the risk of a spike in mosquito-borne diseases in Kenya</a>
</strong>
</em>
</p>
<hr>
<h2>Preventive measures</h2>
<p>Kenya should consider mass vaccinations targeting all age groups in high-risk counties. This <a href="https://pubmed.ncbi.nlm.nih.gov/20101817/">happened</a> in Côte d’Ivoire between September and October 2001, when up to 2.61 million people were vaccinated in a 12-day period in Abidjan.</p>
<p>It’s also advisable to have sustained vector surveillance and control programmes. This could include the use of insecticide at mosquito breeding sites, especially stagnant water. </p>
<p>Communities can help manage the environment to reduce mosquito breeding sites. People can wear clothing that minimises skin exposure, and use mosquito repellents. The usefulness of insecticide-treated bed nets is limited by the fact that <em>Aedes</em> mosquitoes bite during the daytime.</p>
<p>Prompt detection of yellow fever and rapid response through emergency vaccination campaigns are essential for controlling outbreaks. The World Health Organisation <a href="https://www.who.int/news-room/fact-sheets/detail/yellow-fever">recommends</a> there should be at least one national laboratory for performing and confirming yellow fever blood tests in every risk country. Any confirmed case of yellow fever in an unvaccinated population should be considered an outbreak. The response should include emergency measures and long-term immunisation plans. </p>
<p>The populations most at risk need to be made aware and given essential information about prevention and the disease itself. Health workers should be trained in how to collect samples for diagnostic confirmation.</p>
<p>An emergency stockpile of vaccines is necessary for timely and equitable access during emergencies. </p>
<p>The 2005 <a href="https://www.who.int/ith/annex7-ihr.pdf">International Health Regulations</a> must be applied to travellers to and from countries at risk. Port and border control authorities need to be actively engaged to screen travellers.</p><img src="https://counter.theconversation.com/content/179435/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eunice Anyango Owino receives funding from the National Research Fund, Kenya and is an Entomologist interest in controlling vector borne diseases, at the Department of Biology, University of Nairobi, Kenya</span></em></p>The country’s urban centres where unvaccinated people live in crowed settlements are key risk areas.Eunice Anyango Owino, Medical Entomologist at the School of Biological Sciences, University of NairobiLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1676172021-11-03T12:29:25Z2021-11-03T12:29:25ZPreventing future pandemics starts with recognizing links between human and animal health<figure><img src="https://images.theconversation.com/files/427568/original/file-20211020-19033-hhgo6g.jpg?ixlib=rb-1.1.0&rect=18%2C6%2C2008%2C1526&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Disturbing the habitats of horseshoe bats, like these in Borneo, increases the risk of virus spillover.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/nhwHdN">Mike Prince/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>The COVID-19 pandemic has demonstrated that zoonotic diseases – infections that pass from animals to humans – can present tremendous threats to global health. More than 70% of emerging and reemerging pathogens <a href="https://www.worldbank.org/en/news/feature/2020/07/09/qa-how-preventing-zoonotic-diseases-can-help-curb-covid-19-and-other-infectious-diseases">originate from animals</a>. That probably includes the SARS CoV-2 virus, which scientists <a href="http://dx.doi.org/10.1126/science.abh0117">widely believe originated in bats</a>. </p>
<p>There are still questions about specifically where the SARS-CoV-2 virus emerged. But experts across the globe agree that communities can take steps to reduce the risk of future spillovers. A key is for veterinarians, doctors and scientists to work together, recognizing how closely connected human health is with that of animals and of the habitats that we share – an approach known as <a href="https://www.cdc.gov/onehealth/basics/index.html">One Health</a>.</p>
<p>To prevent new pandemics, scientists need to identify specific locations where viruses are most likely to make the jump from animals to humans. In turn, this requires understanding how human behaviors – from deforestation to fossil fuel combustion to conflict to cultural activities – contribute to spillover risks. </p>
<p>We focus on <a href="https://vetprofiles.tufts.edu/profile/deborah-t-kochevar/">global One Health research and education</a> and <a href="https://www.researchgate.net/profile/Guilherme-Werneck">epidemiology of infectious diseases</a>, and we served on a science task force convened by the Harvard T.H. Chan School of Public Health and the Harvard Global Health Institute to evaluate current knowledge of how to prevent spillovers. The <a href="https://cdn1.sph.harvard.edu/wp-content/uploads/sites/2343/2021/08/PreventingPandemicsAug2021.pdf">task force report</a> noted that a <a href="http://dx.doi.org/%2010.1126/science.abc3189">recent analysis</a> estimates the costs of addressing spillover at high-risk interfaces through One Health approaches and forest conservation at US$22 billion to $31 billion per year. These costs are dwarfed by the estimated global <a href="https://www.oecd-ilibrary.org/economics/oecd-economic-outlook/volume-2021/issue-1_edfbca02-en">GDP loss of nearly $4 trillion</a> in 2020 due to the COVID-19 pandemic. </p>
<p>In our view, coordinated investment based on a One Health approach is needed to initiate and sustain global prevention strategies and avoid the devastating costs of pandemic response.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/427570/original/file-20211020-19-1cj0tz0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Infographic naming specialties that contribute to One Health." src="https://images.theconversation.com/files/427570/original/file-20211020-19-1cj0tz0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/427570/original/file-20211020-19-1cj0tz0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/427570/original/file-20211020-19-1cj0tz0.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/427570/original/file-20211020-19-1cj0tz0.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/427570/original/file-20211020-19-1cj0tz0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/427570/original/file-20211020-19-1cj0tz0.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/427570/original/file-20211020-19-1cj0tz0.jpeg?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"></a>
<figcaption>
<span class="caption">One Health is a strategy that seeks to build bridges connecting physicians, veterinarians, environmental scientists, public health professionals and other specialists to protect the health of all species.</span>
<span class="attribution"><a class="source" href="https://www.cdc.gov/onehealth/images/social-media/one-health-involves-everyone-fb-tw.jpg">CDC</a></span>
</figcaption>
</figure>
<h2>Recognizing risky zones</h2>
<p>Identifying high-risk areas for zoonotic spillover is challenging. People and wildlife move around a lot, and exposure may not lead immediately to infection or produce symptoms that clearly reflect exposure to pathogens. </p>
<p>But researchers can make predictions by combining data on human and livestock density with that on environmental conditions, such as deforestation and land use changes, that can enable pathogens to spread from wildlife to humans. For instance, there are areas in China, Indonesia, India and Bangladesh where development has fragmented forests and extended animal farming and human communities near the natural habitats of <a href="https://www.britannica.com/animal/horseshoe-bat">horseshoe bats</a>. This group of bats, which includes more than 100 species, has been implicated as a reservoir for many coronaviruses. </p>
<p>It’s not uncommon for bat-borne diseases to spill over to humans. Sometimes it happens directly: For example, bats in Bangladesh have repeatedly transmitted <a href="https://doi.org/10.1073/pnas.2000429117">Nipah virus</a> to humans. Or the pathogen can move indirectly via intermediate hosts. For example, in 1994 bats in Australia infected horses with Hendra virus, a respiratory disease that <a href="http://dx.doi.org/10.3201/eid1602.090780">then passed to humans</a>.</p>
<p>In Brazil, yellow fever is endemic in the jungles, spread mainly between monkeys via mosquitoes. People in the country occasionally contract it from mosquito bites, and deforestation and land conversion for farming are increasing the risk of greater spillovers. There is rising concern that the disease could be introduced into Brazil’s large cities, where <em>Aedes aegypti</em> mosquitoes are widespread and could <a href="https://doi.org/10.1038/s41598-017-05186-3">transmit it on a large scale</a>. </p>
<p>There also are specific human behaviors that may further increase the risk of spillovers. They include work that puts humans in direct contact with or near animals, such as <a href="https://www.batcon.org/article/guano-bats-gift-to-gardeners/">harvesting bat guano (dung) for fertilizer</a>, and <a href="https://theconversation.com/the-new-coronavirus-emerged-from-the-global-wildlife-trade-and-may-be-devastating-enough-to-end-it-133333">buying and selling wild animals or animal parts</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/OJjZX9iINPk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Tropical deforestation, wildlife trade and raising livestock near forest edges are thought to be major drivers of zoonotic disease spillover.</span></figcaption>
</figure>
<p>Daily routines related to storing food and eating wildlife meat can also create risks. For example, Ebola virus outbreaks in Nigeria have been associated with <a href="https://doi.org/10.1007/s10935-020-00619-8">butchering and eating bushmeat</a>. </p>
<p>People in areas with a high risk of spillover don’t need to stop living their lives. But they do need to recognize that some actions are more risky than others and take appropriate safety precautions, such as wearing protective equipment and making sure that bushmeat is properly handled and cooked.</p>
<h2>The importance of teamwork</h2>
<p>In our view, it is essential for researchers and governments to understand and embrace the central concept that the health of animals, people and the environment is closely connected, and factors that affect one can affect all. Ideally, problem-solving teams form that address prevention from the community and district levels to the ranks of health, animal and environmental ministries.</p>
<p>Members of local communities are most likely to know where people run the highest risk of coming in contact with animals that may carry infectious diseases. By listening to them, veterinary and medical health professionals, as well as foresters and land managers, can develop strategies that are more likely to decrease the risk of spillover.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/428587/original/file-20211026-19-1mcpdvb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Technician in protective suit takes blood sample from a camel." src="https://images.theconversation.com/files/428587/original/file-20211026-19-1mcpdvb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/428587/original/file-20211026-19-1mcpdvb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/428587/original/file-20211026-19-1mcpdvb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/428587/original/file-20211026-19-1mcpdvb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/428587/original/file-20211026-19-1mcpdvb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/428587/original/file-20211026-19-1mcpdvb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/428587/original/file-20211026-19-1mcpdvb.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"></a>
<figcaption>
<span class="caption">Camels infected with Middle East respiratory syndrome coronavirus (MERS-CoV) can pass the virus to humans through direct or indirect contact. Since 2012 MERS has killed more than 800 people in the Middle East, Africa and South Asia. Testing is an important tool for detecting infected animals.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/Y67Jos">Awadh Mohammed Ba Saleh, CDC Global/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Organizations such as the <a href="https://pdf.usaid.gov/pdf_docs/PA00TTB3.pdf">U.S. Agency for International Development</a>, the <a href="https://www.fao.org/emergencies/fao-in-action/stories/stories-detail/en/c/1418052/">Food and Agriculture Organization of the United Nations</a>, <a href="https://www.health.go.ug/cause/uganda-one-health-strategic-plan-2018-2022/">national governments</a> and <a href="https://onehealthbd.org/">civil society groups</a> are investing in One Health platforms across selected countries in Africa and Asia. These networks are typically anchored in government ministries. They can also include nongovernmental organizations and civil society groups committed to advancing health and well-being through a One Health framework.</p>
<p>[<em>Over 115,000 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>
<p>For example, many countries have separate databases to track infectious disease outbreaks in humans and animals. Connecting these systems across government ministries and agencies can improve information exchange between them and lead to better understanding of spillover risks. </p>
<p>We believe that preparing for the next pandemic must include preventing it at its source. Our best chance to succeed is to coordinate research and design of spillover interventions, recognizing that the health of humans, animals and nature are connected.</p><img src="https://counter.theconversation.com/content/167617/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deborah Kochevar receives funding from the U.S. Agency for International Development. She is a member of the boards of Charles River Laboratories and Elanco, a pharmaceutical company that produces medicines and vaccinations for pets and livestock. </span></em></p><p class="fine-print"><em><span>Guilherme Werneck receives funding from The Brazilian Research Council (CNPq) and the Carlos Chagas Filho Foundation for Research Support in the State of Rio de Janeiro (FAPERJ). </span></em></p>How can nations prevent more pandemics like COVID-19? One priority is reducing the risk of diseases’ jumping from animals to humans. And that means understanding how human actions fuel that risk.Deborah Kochevar, Professor of Comparative Pathobiology and Dean Emerita, Cummings School of Veterinary Medicine; Senior Fellow, The Fletcher School, Tufts UniversityGuilherme Werneck, Professor of Epidemiology, Universidade Federal do Rio de Janeiro (UFRJ)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1699242021-10-21T12:45:18Z2021-10-21T12:45:18ZThe American founders didn’t believe your sacred freedom means you can do whatever you want – not even when it comes to vaccines and your own body<figure><img src="https://images.theconversation.com/files/427319/original/file-20211019-18-atnfa9.jpeg?ixlib=rb-1.1.0&rect=23%2C0%2C5298%2C3766&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Protests against mandates and quarantines get the Founding Fathers' ideas wrong.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/small-group-of-approximately-50-people-hold-open-solvang-news-photo/1222462576?adppopup=true">George Rose/Getty Images</a></span></figcaption></figure><p>President <a href="https://www.nytimes.com/2021/09/09/us/politics/biden-mandates-vaccines.html">Joe Biden has mandated vaccines</a> for a large part of the American workforce, a requirement that has prompted <a href="https://www.bostonglobe.com/2021/10/14/metro/new-hampshire-protests-over-covid-mandates-roil-state-local-governments/">protest from those opposed to the measure</a>.</p>
<p>Meanwhile, a similar move in New York City to enforce vaccinations has resulted in more than <a href="https://nypost.com/2021/10/09/over-a-dozen-businesses-fined-for-flouting-nyc-vaccine-mandate/">a dozen businesses’ being fined for flouting the rules</a>.</p>
<p>The basic idea behind the objections: Such mandates, which also extend to requirements to wear masks and quarantine if exposed to COVID-19, are a breach of the Constitution’s <a href="https://www.law.cornell.edu/constitution/amendmentxiv">14th Amendment</a>, which states that “no state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States.” </p>
<p>The objectors ask: Aren’t mandates un-American?</p>
<p>As a scholar who has spent decades trying to unravel the hurdles that mark the beginning of this nation, I offer some facts in response to that question – a few very American facts: Vaccination mandates have <a href="https://www.governing.com/now/the-long-history-of-mandated-vaccines-in-the-united-states">existed in the past</a>, even though they have similarly <a href="https://www.nytimes.com/2021/09/09/us/politics/vaccine-mandates-history.html">sparked popular rage</a>. </p>
<p>No vaccination foe, no latter-day fan of the Gadsden Flag’s “<a href="https://theconversation.com/yellow-gadsden-flag-prominent-in-capitol-takeover-carries-a-long-and-shifting-history-145142">DONT TREAD ON ME</a>” message, would ever gain the posthumous approval of the American founders.</p>
<p>George Washington, John Adams, Thomas Jefferson, Alexander Hamilton and the rest of the group cultivated different visions about America. But they agreed on one principle: They were unrelenting on the notion that circumstances often emerge that require public officials to pass acts that abridge individual freedoms.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/427287/original/file-20211019-19-2btmux.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A print of Gen. George Washington standing among his fellow Revolutionary War generals." src="https://images.theconversation.com/files/427287/original/file-20211019-19-2btmux.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/427287/original/file-20211019-19-2btmux.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/427287/original/file-20211019-19-2btmux.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/427287/original/file-20211019-19-2btmux.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/427287/original/file-20211019-19-2btmux.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/427287/original/file-20211019-19-2btmux.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/427287/original/file-20211019-19-2btmux.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=529&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Gen. George Washington, center, ordered smallpox inoculations for his soldiers, saying there was ‘no possible way of saving the lives of most of those who had not had it, but by introducing innoculation generally.’</span>
<span class="attribution"><a class="source" href="https://lccn.loc.gov/2006691571">Ritchie, Alexander Hay, engraver; Library of Congress Prints and Photographs Division</a></span>
</figcaption>
</figure>
<h2>Keen sense of civic duty</h2>
<p>Most of the founders, to begin with, were slave owners, not especially concerned about trampling over and <a href="https://constitution.congress.gov/constitution/amendment-1/">abridging</a> the rights of the persons they held in bondage. But even when they dealt with those they deemed to be their peers, American citizens, their attitude was rather authoritarian – at least by today’s standards.</p>
<p>In 1777, during the American Revolution, Washington had his officers and troops <a href="https://www.mountvernon.org/video/view/7O5xE5hMNkU?pid=PLr40fFkNNADFEgbM2t-CG0kGnHRDHZoje">inoculated against smallpox</a>. The procedure was <a href="https://www.monticello.org/site/research-and-collections/inoculation">risky</a>. But for Washington, the pros outweighed the cons. It was an order, an actual mandate, not an option that individuals could discuss and eventually decide. </p>
<p>“After every attempt to stop the progress of the small Pox,” Washington explained to the New York Convention, “I found, that it gained such head among the Southern Troops, that there was no possible way of saving the lives of most of those who had not had it, <a href="https://founders.archives.gov/?q=%22After%20every%20attempt%20to%20stop%20the%20progress%20of%20the%20small%20Pox%22&s=1111311111&sa=&r=1&sr=">but by introducing innoculation generally</a>.”</p>
<p>During the summer of 1793 an epidemic of yellow fever <a href="https://www.history.com/news/yellow-fever-outbreak-philadelphia">struck Philadelphia</a>, then the American capital. It shattered the city’s health and political infrastructure. Food supplies dwindled; business stopped. Government – federal, state and municipal – was suspended. Within just three months, 5,000 out of nearly 55,000 inhabitants died of the infection.</p>
<p>Public hysteria took off. Philadelphians at first pinned the outbreak on the arrival of refugees from the French colony of Saint-Domingue who were escaping that island’s <a href="https://www.britannica.com/topic/Haitian-Revolution">slave revolution</a>. </p>
<p>But there was also heroism. Black clergymen <a href="https://www.britannica.com/biography/Richard-Allen">Richard Allen</a> and <a href="https://en.wikipedia.org/wiki/Absalom_Jones">Absalom Jones</a>, for example, <a href="https://theconversation.com/how-philadelphias-black-churches-overcame-disease-depression-and-civil-strife-153374">tirelessly transported the sick, administered remedies and buried the dead</a>. </p>
<p><a href="https://www.pabook.libraries.psu.edu/literary-cultural-heritage-map-pa/feature-articles/philadelphia-under-siege-yellow-fever-1793">Urged on by Gov. Thomas Mifflin</a>, the Pennsylvania state Legislature imposed sweeping quarantines. And almost everyone complied. </p>
<p><a href="https://www.britannica.com/biography/Henry-Knox">Henry Knox, then the U.S. secretary of war</a>, didn’t object. Knox had fought during the Revolution. He had risked his life on many battles. He had developed a keen sense of what “civic duty” means: “I have yet six days quarantine to perform,” he wrote to President Washington, “which of the choice of evils <a href="https://founders.archives.gov/?q=%22I%20have%20yet%20six%20days%C2%A0quarantine%C2%A0to%20perform%22&s=1111311111&sa=&r=1&sr=">is the least</a>.”</p>
<h2>‘Without a flinch’</h2>
<p>The epidemic didn’t abate as quickly as expected. By September 1794 <a href="https://www.pbs.org/wgbh/americanexperience/features/fever-major-american-epidemics-of-yellow-fever/">the yellow fever lingered in Baltimore</a>, where it had spread from Philadelphia. In 1795 it reached New York City.</p>
<p>One John Coverdale, from Henderskelfe, Yorkshire, England, wrote President Washington a long letter. He advocated more drastic measures, including three weeks of quarantine and policemen strategically placed in every corner to hinder people from passing from zone to zone; and he wanted people “to carry with them <a href="https://founders.archives.gov/?q=%22certificates%20either%20of%20their%20coming%20from%20places%20not%20infected%22&s=1111311111&sa=&r=1&sr=">certificates</a> either of their coming from places not infected or of their passing the line by permission.”</p>
<p>In other words, a quarantine, lockdown and vaccine passports. </p>
<p>No politician we know of at the time considered such measures un-American. In May of 1796, Congress adopted, and President Washington signed, the <a href="https://archive.org/details/lawsofunitedstat03unit/page/314/mode/2up?view=theater">first federal quarantine law</a>. There wasn’t much controversy. In 1799, Congress passed a second and more restrictive <a href="https://www.loc.gov/resource/rbpe.22401000/?sp=1">quarantine law</a>. President Adams signed it without a flinch.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/427271/original/file-20211019-19-a5pf9z.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A head-and-shoulders portrait of Alexander Hamilton." src="https://images.theconversation.com/files/427271/original/file-20211019-19-a5pf9z.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/427271/original/file-20211019-19-a5pf9z.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=753&fit=crop&dpr=1 600w, https://images.theconversation.com/files/427271/original/file-20211019-19-a5pf9z.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=753&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/427271/original/file-20211019-19-a5pf9z.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=753&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/427271/original/file-20211019-19-a5pf9z.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=946&fit=crop&dpr=1 754w, https://images.theconversation.com/files/427271/original/file-20211019-19-a5pf9z.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=946&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/427271/original/file-20211019-19-a5pf9z.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=946&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Founding Father Alexander Hamilton stated, ‘It shall never be said, with any color of truth, that my ambition or interest has stood in the way of the public good.’</span>
<span class="attribution"><a class="source" href="https://www.loc.gov/item/2016816335/">Library of Congress Prints and Photographs Division</a></span>
</figcaption>
</figure>
<h2>‘Ambition’ vs. public good</h2>
<p>So apparently it’s not certificates, quarantines and vaccine mandates that are un-American, <a href="https://twitter.com/Jim_Jordan/status/1434978332513292291">as some maintain today</a>. </p>
<p>The argument that individual rights trump the greater good is un-American, or at least out of step with American tradition. It’s an attitude that the founders would have put under <a href="https://yalebooks.yale.edu/book/9780300182804/ambition-history">the encompassing banner of “ambition</a>.”</p>
<p>“Ambition” comes when individuals are blinded by their little – or large – egotisms and personal interests. They lose track of higher goals: the community, the republic, the nation. In the most severe cases, ambition turns anti-social.</p>
<p>Ambitious individuals, the founders were sure, are persons stripped of their membership in a community. They choose to relegate themselves to their solitary imagination. They have become slaves to their own opinions.</p>
<p><a href="https://en.wikipedia.org/wiki/Alexander_Hamilton">Alexander Hamilton</a> was tired of being turned into the butt of endless accusations: “<a href="https://founders.archives.gov/?q=%22my%20ambition%20or%20interest%20has%20stood%20in%20the%20way%22&s=1111311111&sa=&r=2&sr=">It shall never be said</a>, with any color of truth, that my ambition or interest has stood in the way of the public good.”</p>
<p>When facing a quarantine, a mandate, or similar momentary abridgments of their liberties, many Americans today react the same way Hamilton did. Like Hamilton, they look beyond themselves, their opinions, their interests. They don’t lose sight of the public good.</p>
<p>Others remain ambitious.</p>
<p>[<em>The Conversation’s Politics + Society editors pick need-to-know stories.</em> <a href="https://theconversation.com/us/newsletters/politics-weekly-74/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=politics-need-to-know">Sign up for Politics Weekly</a>._]</p><img src="https://counter.theconversation.com/content/169924/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Maurizio Valsania 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>The Founding Fathers were unrelenting in their commitment to the idea that circumstances can arise that require public officials to take actions abridging individual freedoms.Maurizio Valsania, Professor of American History, Università di TorinoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1660472021-08-17T14:39:09Z2021-08-17T14:39:09ZThree things you should know about mosquitoes<figure><img src="https://images.theconversation.com/files/415996/original/file-20210813-20-bi0lsj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Aedes mosquito can transmit several viruses including dengue, yellow fever and Zika. </span> <span class="attribution"><span class="source">Joao Paulo Burini/GettyImages</span></span></figcaption></figure><p>For thousands of years malaria was a mysterious illness affecting people across the globe. Even the name of the disease, ‘malaria’, derived from two Italian words meaning ‘bad air’, highlights the confusion around the transmission of this disease. It was only following the discovery of malaria parasites in the gut of Anopheles mosquitoes in India by <a href="https://www.cdc.gov/malaria/about/history/laveran.html">Sir Ronald Ross</a> <a href="https://www.cdc.gov/malaria/about/history/ross.html">on 20 August 1897</a> that a clearer picture of the role of the mosquito in the malaria transmission cycle emerged. </p>
<p>Ross was awarded a Nobel prize for this discovery, and since 1930 World Mosquito Day has been observed on 20 August to commemorate this important finding and highlight the role of mosquitoes in the health and well-being of humans.</p>
<p>Mosquitoes are among the <a href="https://www.statista.com/statistics/448169/deadliest-creatures-in-the-world-by-number-of-human-deaths/">deadliest animals</a> in the world. Half of the deaths attributed to these insects are associated with <a href="https://www.who.int/en/news-room/fact-sheets/detail/malaria">malaria</a>. But mosquitoes are carriers of a number of <a href="https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(20)30269-2/fulltext">other parasites, viruses and nematodes (roundworms)</a> that threaten the health of humans. It’s surprising, then, that the general public tends to be ill-informed about mosquitoes in general.</p>
<p>There are still many things scientists don’t understand either. For example, how do mosquitoes <a href="https://link.springer.com/article/10.1007/s00441-020-03407-2">find us</a>? What do they <a href="https://www.sciencedirect.com/science/article/pii/S0960982219303082">like</a> about us? And why are some mosquitoes just a biting pest while others <a href="https://www.sciencedirect.com/science/article/abs/pii/S1471492209002621#:%7E:text=A%20mosquito%20can%20be%20considered,to%20sporozoites%20in%20the%20saliva">are deadly</a>? In addition, <a href="https://www.nature.com/articles/s41598-019-49065-5">new mosquito species</a> are still being described and <a href="https://pubmed.ncbi.nlm.nih.gov/19706923/">discovered</a>. Species previously not thought of as vectors are now being implicated in the <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-019-2889-5">transmission of malaria</a>.</p>
<p>As malaria research scientists we have chosen some interesting facts about mosquitoes to share with you. We also highlight what they mean for public health. </p>
<h2>1. Not all mosquitoes are created equal</h2>
<p>Mosquitoes are generally thought of as the noisy nuisance that pesters you at night. But they differ greatly in their biology and distribution. There are around 3,500 mosquito species belonging to five genera. </p>
<p>The whiny mosquito that instantly comes to mind is most likely a member of the <a href="https://entnemdept.ufl.edu/creatures/aquatic/southern_house_mosquito.htm"><em>Culex</em></a> genus, which is active at night. These mosquitoes lay their eggs as egg rafts in a range of different water bodies (breeding sites). They are associated with diseases like West Nile virus and Japanese encephalitis in some regions, but not in South Africa.</p>
<p>In contrast, <a href="https://entnemdept.ufl.edu/creatures/aquatic/aedes_aegypti.htm"><em>Aedes</em> mosquitoes</a> are mostly encountered during the day. These mosquitoes are black with distinctive white or silvery markings and breed in containers such as tyres and tree holes. They lay single eggs on the damp sides of a water body rather than directly onto water. These mosquitoes are capable of transmitting a range of deadly viruses including dengue, yellow fever and Zika. </p>
<p>Unlike <em>Aedes</em> and <em>Culex</em> mosquitoes, <a href="https://entnemdept.ufl.edu/creatures/aquatic/Anopheles_gambiae.htm"><em>Anopheles</em> mosquitoes</a> make only a soft buzzing sound and hence are often referred to as the “silent killers”. Of the approximately 460 <em>Anopheles</em> species, at least 70 have been implicated in malaria transmission. Adult <em>Anopheles</em> mosquitoes are brown or black with dappled wings and are generally most active between dusk and dawn. They also have a very distinctive resting posture, with their abdomens pointing away from a surface at an angle of about 45 degrees as opposed to resting parallel to the surface they are resting on. Female anopheline mosquitoes also lay single eggs on the surface of water bodies and hatched larvae lie parallel to the surface of the water. </p>
<h2>2. Some mosquitoes do not bite at all</h2>
<p>Female anopheline mosquitoes interact with you when in search of a blood meal. They use the proteins in blood to assist with egg production. In her search for essential proteins, the <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0050464">female malaria mosquito bites</a> – she doesn’t sting. Male malaria mosquitoes are harmless and play a critical role in the pollination of plants.</p>
<p><em>Toxorhynchites</em> mosquitoes, also known as <a href="https://entomologytoday.org/2019/03/19/toxorhynchites-rutilus-mosquito-appetite-other-mosquitoes/">elephant mosquitoes</a>, do not have biting mouth parts. Their larvae are, however, actively carnivorous and eat other mosquito larvae. In certain conditions they have been used for <a href="https://commonnaturalist.com/2017/05/11/toxorhynchites-the-mosquitoes-that-hunt-other-mosquitoes/">biological control</a>.</p>
<p>It is also worth noting some mosquito look-alikes, notably crane flies. These large flies cannot bite, but are <a href="https://www.mosquitoes.org/mosquito-like-insects">commonly mistaken</a> for gigantic mosquitoes.</p>
<h2>3. Mosquitoes transmit only certain diseases</h2>
<p>Despite being associated with a wide range of diseases, mosquitoes are not capable of transmitting viruses such as <a href="https://www.healthline.com/health/can-mosquitoes-transmit-hiv#how-hiv-spreads">HIV</a>, <a href="https://www.cdc.gov/vhf/ebola/pdf/top-10-things.pdf">Ebola</a> or the<a href="https://www.nature.com/articles/s41598-020-68882-7">novel coronavirus</a>.</p>
<h2>How to protect yourself</h2>
<p>Mosquito-borne diseases are often preventable. But they are unfortunately associated with high levels of poverty and weak health systems. This makes controlling and preventing these diseases very challenging.</p>
<p>It is therefore very important to protect yourself from mosquito bites when in an area with a high risk of exposure to mosquito-borne diseases. Consider covering exposed areas of skin with repellents and sleeping under a mosquito net. </p>
<p>There are drugs which offer protection for travellers who haven’t been exposed to malaria before (which is most of South African population) and, despite urban legend, they do not mask symptoms of the disease. If you develop a fever after travelling to a malaria endemic area, you should tell your healthcare provider where you have been.</p>
<p>Vaccines for yellow fever and Japanese encephalitis are available and several more are in development. There has been promising <a href="https://www.who.int/initiatives/malaria-vaccine-implementation-programme">malaria vaccine news</a> but meanwhile it’s wise to take precautions.</p><img src="https://counter.theconversation.com/content/166047/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 and the National Health Laboratory Services Services Research Trust. She is affiliated with Centre for Emerging Zoonotic Diseases, National Institute for Communicable Diseases and the Wits Research for Malaria, University of Witwatersrand</span></em></p><p class="fine-print"><em><span>Jaishree Raman receives funding from the National Research Foundation of South Africa, the National Health Laboratory Services Research Trust and the Bill and Melinda Gates Foundation. She is affiliated with Centre for Emerging Zoonotic Diseases, National Institute for Communicable Diseases, the Wits Research for Malaria, University of Witwatersrand and the UP Institute for Sustainable Malaria Control, University of Pretoria.</span></em></p>Mosquitoes are among the deadliest animals in the world. Half of the deaths attributed to them are associated with malaria. But they carry other parasites and viruses that threaten human health.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/1621102021-07-06T15:00:16Z2021-07-06T15:00:16ZWhy Africa’s push to make vaccines should look further than COVID-19<figure><img src="https://images.theconversation.com/files/405100/original/file-20210608-130350-1ba9vr4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">South African President Cyril Ramaphosa, Deputy president David Mabuza, Health Minister Dr Zweli Mkhize visiting the Aspen Pharmacare sterile manufacturing facility. </span> <span class="attribution"><span class="source">Lulama Zenzile/Die Burger/Gallo Images via Getty Images</span></span></figcaption></figure><p>It’s unlikely that vaccine manufacturing will offer Africa a quick fix for COVID-19. Countries on the continent are grappling with a diverse array of challenges. These include vaccine hesitancy, supply bottlenecks and a lack of operational funding and human resources to administer jabs. </p>
<p>Still, the political will to boost local manufacturing of vaccines is rising across the globe, including in Africa – and has never been this high.</p>
<p>The reason is simple. COVID-19 has shown that regions and countries take care of their own people first when crises hit. Africa wants to be able to do the same. To do so, the continent must seize new opportunities to fast-track the development of vaccine manufacturing capacity and to boost regulatory processes.</p>
<p>In 2020, about 40 African countries participated in a World Health Organisation (WHO) <a href="https://www.who.int/director-general/speeches/detail/director-general-s-opening-remarks-for-panel-is-africa-ready-to-finance-its-own-vaccine">training marathon</a> to build manufacturing capacity.
All 54 countries on the continent also supported Ethiopia’s recently passed resolution to the <a href="https://healthpolicy-watch.news/us-backs-trips-waiver-to-strip-vaccines-of-patent-protection-as-wha-pushes-local-vaccine-capacity/">74th World Health Assembly</a>, focused on strengthening local production of medicine and health technology. At the recent <a href="https://www.g20.org/the-global-health-summit-ended-with-the-signing-of-the-rome-declaration.html">G20 Global Health Summit</a>, the European Commission also announced a new initiative on manufacturing in Africa, backed by €1 billion. </p>
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Read more:
<a href="https://theconversation.com/trips-waiver-us-support-is-a-major-step-but-no-guarantee-of-covid-19-vaccine-equity-160638">TRIPS waiver: US support is a major step but no guarantee of COVID-19 vaccine equity</a>
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<p>That’s critical because manufacturing vaccine doesn’t come cheap. Success will depend heavily on support – in cash and in kind – from developed countries. It takes hundreds of millions of dollars to produce a <a href="https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(18)30346-2/fulltext">new vaccine</a>. </p>
<p>There is hope for relaxation of <a href="https://theconversation.com/trips-waiver-us-support-is-a-major-step-but-no-guarantee-of-covid-19-vaccine-equity-160638">intellectual property rights</a>. These are necessary to open the way to local manufacturing of existing vaccines. </p>
<p>But the production process for new vaccines can take as long as five to 10 years. The typical vaccine roadmap begins with exploratory research, followed by pre-clinical and clinical safety and efficacy testing on animals and humans – and regulatory reviews and approvals for licensing. Only then can the manufacturing process begin.</p>
<p>This requires a significant body of skills. Local expertise in areas such as research and development, regulatory expertise and quality assurance must be strengthened too. </p>
<h2>Local manufacturing</h2>
<p>It will take several more years before countries are fully prepared to manufacture new vaccines to the scale of contributing significantly to global output. Therefore, governments should adopt a longer-term view that prioritises the most urgent health challenges in the region. This vision must be about manufacturing vaccine generally, rather than COVID-19 vaccines specifically.</p>
<p>Africa has <a href="https://www.nature.com/articles/d41586-021-01048-1">54 countries</a> and 1.2 billion people, but produces only 1% of all the vaccines it administers. The continent also faces a heavy burden of disease. Over <a href="https://www.who.int/news-room/fact-sheets/detail/malaria#:%7E:text=Disease%20burden&text=cases%20in%202018.-,The%20estimated%20number%20of%20malaria%20deaths%20stood%20at%20409%20000,all%20malaria%20cases%20and%20deaths">90%</a> of the world’s malaria deaths and <a href="https://www.afro.who.int/health-topics/hivaids">70%</a> of all people living with HIV are in Africa.</p>
<p>So far, the continent has only a few producers of vaccines. Statutes signed between the government of Senegal and the Institut Pasteur in <a href="https://www.avmi-africa.org/manufacturers/#1490181278853-496b3000-e3fc">2009</a> allowed the country to manufacture yellow fever vaccines. There are <a href="https://www.avmi-africa.org/manufacturers/#1490181277540-254a2bb0-9973">six other vaccine manufacturing institutes</a>. One is <a href="https://www.vacsera.com/">VACSERA </a>in Egypt, the oldest vaccine manufacturer in Africa. Egypt is slated to complete the production of <a href="https://egyptindependent.com/egypt-to-produce-40-million-doses-of-sinovac-vaccine-in-2021/">40 million</a> doses of China’s Sinovac COVID-19 vaccine domestically by the end of 2021. In South Africa, the pharmaceutical company<a href="https://www.aspenpharma.com/"> Aspen</a> will be manufacturing doses of the <a href="https://www.reuters.com/article/uk-health-coronavirus-safrica-johnson-jo-idUSKBN2BO5IA">Johnson & Johnson</a> COVID-19 vaccine under licence.</p>
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Read more:
<a href="https://theconversation.com/vaccine-production-in-south-africa-how-an-industry-in-its-infancy-can-be-developed-153204">Vaccine production in South Africa: how an industry in its infancy can be developed</a>
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<p>Most local companies engage only in packaging and labelling, and occasionally fill-and-finish steps. But it’s noteworthy that there are about <a href="https://www.afro.who.int/news/what-africas-vaccine-production-capacity">80 sterile injectables facilities</a> on the continent. These produce a broad range of fill-and-finish sterile solutions and emulsions including anaesthetics, eye drops and multi-drug resistant tuberculosis vaccines. Significant financial commitment would be required to transform them into fully integrated manufacturing facilities. But these operations have built solid track records with partners and suppliers that will benefit expansion plans.</p>
<h2>Integrating policies</h2>
<p>Africa’s segmented markets, and often small economies, are at odds with the fact that vaccines are mostly produced in large quantities to keep prices down. They require large markets for sustainability. Regulatory bodies that meet international standards are also lacking, presenting a further hurdle.</p>
<p>Integrating national and regional policies and strategies would in effect increase the size of the overall market. All countries could then benefit, regardless of the size of their economy.</p>
<p>More integration will drive agreement on the manufacturing of products in high demand in Africa. It will also expand market access, and help avoid costly duplication. But most importantly, it will help ensure sustainability because most African countries’ markets are too small to support their own manufacturing. </p>
<p>African countries must make better use of regional economic integration platforms such as the <a href="https://www.ecowas.int/">Economic Community of West African States</a>, the <a href="https://www.comesa.int/">Common Market for Eastern and Southern Africa</a>, and the new <a href="https://au.int/en/cfta">African Continental Free Trade Agreement</a>, all of which offer great opportunities. </p>
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Read more:
<a href="https://theconversation.com/africas-free-trade-area-offers-great-promise-but-only-if-risks-are-managed-with-resolve-161535">Africa's free trade area offers great promise. But only if risks are managed with resolve</a>
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<p>The <a href="https://www.un.org/africarenewal/magazine/november-december-2020/afcfta-africa-readying-free-trade-come-january-2021">African Continental Free Trade Area</a>, for example, aims to reduce all trade costs – it will eliminate 90% of tariffs – and enable Africa to integrate further into global supply chains. Cutting red tape and simplifying customs procedures will bring significant income gains. </p>
<p>Strong regulatory capacity and oversight is another building block for vaccine production and product safety. Countries must strengthen their regulatory systems to ensure that all medical products are of the highest quality, and that local manufacturers maintain international standards. This is why it’s critical for member states to urgently ratify the treaty to support the creation of the <a href="https://au.int/en/pressreleases/20200205/african-medicine-agency-ama-treaty">African Medicines Agency</a>. To date, <a href="https://au.int/en/pressreleases/20210507/republic-guinea-deposits-instrument-ratification-african-medicines-agency-ama">seven</a> of the required 15 African Union member states have ratified the treaty.</p>
<p>The World Health Organisation, where I am the regional advisor for vaccine research and regulation in the Africa region, works with member states and partners towards local vaccine manufacture.</p>
<p>In Ethiopia, for example, we are working closely with the Ministry of Health. We’re conducting a feasibility study in respect of the potential for high-standard manufacturing of vaccines. We’re also developing cost estimates for a road map to success.</p>
<p>Ethiopia, home to the second biggest population on the continent, had to pay a hefty US$707 million to procure routine vaccines between 2016 to 2020. That’s an enormous financial burden and sends a very clear message about the urgency for local manufacturing.</p>
<h2>Looking forward</h2>
<p>Africa is facing <a href="https://www.dw.com/en/coronavirus-digest-who-says-africa-urgently-needs-20-million-vaccine-doses/a-57695529">delays in accessing life-saving vaccines</a> for COVID-19. The continent may experience similar delays in the future. The continent faces significant and enduring <a href="https://www.hsph.harvard.edu/news/features/africa-cdc-head-is-driving-a-new-public-health-agenda-on-the-continent/#:%7E:text=March%2012%2C%202020%20%E2%80%93%20Africa%20faces,growing%20burden%20of%20chronic%20diseases">public health threats</a>, including measles, rotavirus, yellow fever and Ebola.</p>
<p>To manage these public health threats, Africa needs its own capacity for vaccine development and production so that it can immunise for childhood diseases and help control outbreaks of highly infectious diseases – including COVID-19.</p><img src="https://counter.theconversation.com/content/162110/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bartholomew Dicky Akanmori is Regional Adviser for Vaccine Research and Regulation in the WHO Regional Office for Africa. </span></em></p>Vaccine manufacturing doesn’t come cheap. It depends heavily on support from developed countries. It also requires much more than relaxing intellectual property rights and a desire for vaccine equity.Bartholomew Dicky Akanmori, Professor Emeritus of Immunology, University of GhanaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1450162020-08-28T12:25:41Z2020-08-28T12:25:41ZHistory tells us trying to stop diseases like COVID-19 at the border is a failed strategy<figure><img src="https://images.theconversation.com/files/355169/original/file-20200827-18-1fw8hni.jpg?ixlib=rb-1.1.0&rect=14%2C21%2C4723%2C3125&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A traveler walks past screeners testing a system of thermal imaging cameras which check body temperatures at Los Angeles International Airport on June. 24, 2020.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/traveler-walks-past-screeners-testing-a-system-of-thermal-news-photo/1252247135?adppopup=true">Mario Tama/Getty Images</a></span></figcaption></figure><p>To explain why the coronavirus pandemic is much <a href="https://www.nytimes.com/2020/07/06/briefing/a-global-comparison-of-coronavirus-cases.html">worse</a> in the U.S. than anywhere else in the world, commentators have blamed the federal government’s <a href="https://www.washingtonpost.com/health/2020/07/19/coronavirus-us-failure/">mismanaged</a> <a href="https://time.com/5850680/u-s-response-covid-19-worse-than-chinas/">response</a> and the <a href="https://www.washingtonpost.com/opinions/2020/07/13/trumps-performance-covid-19-looks-especially-bad-compared-with-rest-world/">lack of leadership</a> from the Trump White House. </p>
<p>Others have pointed to our culture of <a href="https://www.nytimes.com/2020/08/06/us/united-states-failure-coronavirus.html">individualism</a>, the <a href="https://www.nytimes.com/2020/03/15/us/united-states-coronavirus-response.html">decentralized</a> nature of our public health, and our <a href="https://www.pewresearch.org/politics/2020/06/25/republicans-democrats-move-even-further-apart-in-coronavirus-concerns/">polarized politics</a>.</p>
<p>All valid explanations, but there’s another reason, much older, for the failed response: our approach to fighting infectious disease, inherited from the 19th century, has become overly focused on keeping disease out of the country through border controls. </p>
<p>As <a href="https://scholar.google.com/citations?user=gGtuqqIAAAAJ&hl=en">a professor of medical sociology,</a> I’ve studied the response to infectious disease and public health policy. In my new book, “<a href="https://www.umasspress.com/9781625345073/diseased-states/">Diseased States</a>,” I examine how the early experience of outbreaks in Britain and the United States shaped their current disease control systems. I believe that America’s preoccupation with border controls has hurt our nation’s ability to manage the devastation produced by a domestically occurring outbreak of disease. </p>
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<img alt="On the streets of New Orleans, the dying victims of the 1878 yellow fever epidemic." src="https://images.theconversation.com/files/354719/original/file-20200825-16-1ll05vl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/354719/original/file-20200825-16-1ll05vl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=545&fit=crop&dpr=1 600w, https://images.theconversation.com/files/354719/original/file-20200825-16-1ll05vl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=545&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/354719/original/file-20200825-16-1ll05vl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=545&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/354719/original/file-20200825-16-1ll05vl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=685&fit=crop&dpr=1 754w, https://images.theconversation.com/files/354719/original/file-20200825-16-1ll05vl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=685&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/354719/original/file-20200825-16-1ll05vl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=685&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">An 1878 illustration: men dying on the streets of New Orleans during the yellow fever epidemic.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/men-prey-in-the-grips-of-yellow-fever-in-jackson-square-news-photo/931882760?adppopup=true">DEA/Biblioteca Ambrosiana via Getty Images</a></span>
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<h2>Germ theory and the military</h2>
<p>Though outbreaks of yellow fever, smallpox, and cholera occurred throughout the 19th century, the federal government didn’t take the fight against infectious disease seriously until the <a href="https://www.pbs.org/wgbh/americanexperience/features/fever-1878-epidemic/">yellow fever outbreak</a> of 1878. During that same year, President Rutherford B. Hayes signed the <a href="https://doi.org/10.1177/003335491112600117">National Quarantine Act</a>, the first federal disease control legislation. </p>
<p>By the early 20th century, a distinctly American approach to disease control had evolved: “<a href="https://ajph.aphapublications.org/doi/10.2105/AJPH.2009.163956">New Public Health</a>.” It was markedly different from the older European concept of public health, which emphasized sanitation and social conditions. Instead, U.S. health officials were fascinated by the newly popular “germ theory,” which theorized that microorganisms, too small to be seen by the naked eye, caused disease. The U.S. became focused on isolating the infectious. The typhoid carrier <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3959940/">Mary Mallon</a>, known as “Typhoid Mary,” was isolated on New York’s Brother Island for 23 years of her life. </p>
<p>Originally, the military managed disease control. After the yellow fever outbreak, the U.S. <a href="https://careers.publichealth.iu.edu/blog/2018/10/12/a-brief-history-of-the-public-health-service/">Marine Hospital Service</a> (MHS) was charged with operating maritime quarantine stations countrywide. In 1912, the MHS became the U.S. Public Health Service; to this day, that includes the Public Health Service Commissioned Corps led by the surgeon general. Even the Centers for Disease Control and Prevention started as a military organization during World War II, as the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1381908/">Malaria Control in War Areas</a> program. Connecting the military to disease control promoted the notion that an attack of infectious disease was like an <a href="https://books.google.com/books/about/Pestilential_foreign_invasion.html?id=87k9nCGbArsC">invasion</a> of a foreign enemy. </p>
<p>Germ theory and military management put the U.S. system of disease control down a path in which it prioritized border controls and quarantine throughout the 20th century. During the 1918 influenza pandemic, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2862336/">New York City</a> held all incoming ships at quarantine stations and forcibly removed sick passengers into isolation to a local hospital. Other states followed suit. In Minnesota, the city of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2862333/">Minneapolis</a> isolated all flu patients in a special ward of the city hospital and then denied them visitors. During the 1980s, the <a href="https://books.google.com/books/about/Disease_and_Democracy.html?id=0acwDwAAQBAJ&source=kp_book_description">Immigration and Naturalization Service</a> denied HIV-positive persons from entering the country and tested over three million potential immigrants for HIV. </p>
<p>Defending the nation from the external threat of disease generally meant stopping the potentially infectious from ever entering the country and isolating those who were able to gain entry.</p>
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<figcaption><span class="caption">Kaci Hickox was forced to quarantine for 21 days in a after she returned from Africa.</span></figcaption>
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<h2>Our mistakes</h2>
<p>This continues to be our predominant strategy in the 21st century. One of President Trump’s first coronavirus actions was to enforce a travel ban on <a href="https://www.washingtonpost.com/politics/2020/04/07/trumps-claim-that-he-imposed-first-china-ban/">China</a> and then to limit travel from <a href="https://www.bbc.com/news/world-us-canada-51883728">Europe</a>. </p>
<p>His actions were nothing new. In 2014, during the Ebola outbreak, <a href="https://www.latimes.com/local/lanow/la-me-ln-california-orders-ebola-quarantine-protocols-20141029-story.html">California</a>, <a href="https://www.nytimes.com/2014/10/25/nyregion/new-york-ebola-case-craig-spencer.html">New York</a> and <a href="https://www.nhpr.org/post/new-york-new-jersey-will-quarantine-all-travelers-ebola-contact#stream/0">New Jersey</a> created laws to forcibly quarantine health care workers returning from west Africa. New Jersey put this into practice when it isolated U.S. nurse Kaci Hickox after she returned from Sierra Leone, where she was treating Ebola patients.</p>
<p>In 2007, responding to pandemic influenza, the Department of Homeland Security and the CDC developed a “<a href="https://www.cdc.gov/quarantine/do-not-board-faq.html">do not board</a>” list to stop potentially infected people from traveling to the U.S. </p>
<p>When such actions stop outbreaks from occurring, they are obviously sound public policy. But when a global outbreak is so large that it’s impossible to keep out, then border controls and quarantine are no longer useful. </p>
<p>This is what has happened with the coronavirus. With today’s globalization, international travel, and an <a href="https://doi.org/10.1098/rsif.2014.0950">increasing</a> number of pandemics, attempting to keep infectious disease from ever entering the country looks more and more like a futile effort. </p>
<p>[<em>Research into coronavirus and other news from science</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-corona-research">Subscribe to The Conversation’s new science newsletter</a>.]</p>
<p>Moreover, the U.S. preoccupation with border controls means we did not invest as much as we should have in limiting the internal spread of COVID-19. Unlike <a href="https://www.npr.org/sections/goatsandsoda/2020/05/23/861577367/messaging-from-leaders-who-have-tamed-their-countrys-coronavirus-outbreaks">countries</a> that mounted an effective response, the U.S. has lagged behind in <a href="https://fortune.com/2020/08/04/why-covid-19-testing-takes-so-long-coronavirus-test-results-labs-delays-us-how-long/">testing</a>, <a href="https://www.scientificamerican.com/article/contact-tracing-a-key-way-to-slow-covid-19-is-badly-underused-by-the-u-s/">contact tracing</a>, and the development of a robust <a href="https://www.wsj.com/articles/coronavirus-latest-news-06-29-2020-11593420521">health care system</a> able to handle a surge of infected patients. The longstanding focus on stopping an outbreak from ever occurring left us more vulnerable when it inevitably did. </p>
<p>For decades, the U.S. has been underfunding public health. When “swine flu” struck the country in 2009, the CDC said <a href="https://latimesblogs.latimes.com/lanow/2009/11/california-might-miss-swine-flu-vaccination-goal-because-of-medicine-shortage.html">159 million</a> doses of flu shots were needed to cover “high risk” groups, particularly health care workers and pregnant women. We only produced <a href="https://www.wsj.com/articles/SB125735930128328447">32 million</a> doses. And in a pronouncement that now looks prescient, a Robert Wood Johnson Foundation <a href="https://www.tfah.org/report-details/ready-or-not-2009/">report</a> said if the swine flu outbreak had been any worse, U.S. health departments would have been overwhelmed. By the time Ebola appeared in 2014, the situation was no better. Once again, multiple <a href="https://asprtracie.hhs.gov/technical-resources/resource/3544/report-of-the-independent-panel-on-the-us-department-of-health-and-human-services-hhs-ebola-response">government</a> <a href="https://pubmed.ncbi.nlm.nih.gov/28994617/">reports</a> slammed our response to the outbreak. </p>
<p>Many causes exist for the U.S.’s failed response to this crisis. But part of the problem lies with our past battles with disease. By emphasizing border controls and quarantine, the U.S. has disregarded more practical strategies of disease control. We can’t change the past, but by learning from it, we can develop more effective ways of dealing with future outbreaks.</p><img src="https://counter.theconversation.com/content/145016/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Charles McCoy 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>The US response to the coronavirus was slow and problematic, but it also was rooted in a 19th-century way of viewing public health.Charles McCoy, Assistant Professor of Sociology, SUNY PlattsburghLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1396452020-06-25T12:35:23Z2020-06-25T12:35:23ZHow deforestation helps deadly viruses jump from animals to humans<figure><img src="https://images.theconversation.com/files/343503/original/file-20200623-188911-16eqf9f.jpg?ixlib=rb-1.1.0&rect=0%2C10%2C3104%2C2134&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pangolins have been found with covonaviruses that are genetically similar to the one afflicting humans today.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/zimbabwe-game-reserve-guide-matius-mhambe-holds-marimba-a-news-photo/610214710">Jekesai Njikizana/AFP/Getty Images</a></span></figcaption></figure><p>The coronavirus pandemic, suspected of originating in bats and pangolins, has brought the risk of viruses that jump from wildlife to humans into stark focus.</p>
<p>These leaps often happen at the edges of the world’s tropical forests, where deforestation is increasingly bringing people into contact with animals’ natural habitats. Yellow fever, malaria, Venezuelan equine encephalitis, Ebola – all of these pathogens have spilled over from one species to another at the margins of forests.</p>
<p>As <a href="https://id.medicine.ufl.edu/profile/vittor-amy/">doctors</a> and <a href="http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4167488J6">biologists</a> <a href="http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4727511E6&idiomaExibicao=2">specializing in infectious diseases</a>, we have studied these and other zoonoses as they spread in Africa, Asia and the Americas. We found that <a href="http://doi.org/10.1098/rstb.2016.0125">deforestation has been a common theme</a>.</p>
<p>More than half of the world’s tropical deforestation is driven by four commodities: beef, soy, palm oil and wood products. They replace mature, biodiverse tropical forests with monocrop fields and pastures. As the forest is degraded piecemeal, animals still living in isolated fragments of natural vegetation struggle to exist. When human settlements encroach on these forests, human-wildlife contact can increase, and new opportunistic animals may also migrate in.</p>
<p>The resulting disease spread shows the interconnectedness of natural habitats, the animals that dwell within it, and humans.</p>
<h2>Yellow fever: Monkeys, humans and hungry mosquitoes</h2>
<p>Yellow fever, a viral infection transmitted by mosquitoes, famously halted progress on the Panama Canal in the 1900s and shaped the history of Atlantic coast cities from Philadelphia to Rio de Janeiro. Although a yellow fever vaccine has been available since the 1930s, the disease continues to afflict 200,000 people a year, a third of whom die, mostly in West Africa. </p>
<p>The virus that causes it lives in primates and is spread by mosquitoes that tend to dwell high in the canopy where these primates live.</p>
<p>In the early 1990s, a yellow fever outbreak was <a href="http://doi.org/10.4269/ajtmh.1998.59.644">reported for the first time in the Kerio Valley in Kenya</a>, where deforestation had fragmented the forest. Between 2016 and 2018, <a href="https://www.who.int/csr/don/09-march-2018-yellow-fever-brazil/en/">South America saw its largest number of yellow fever cases in decades</a>, resulting in around 2,000 cases, and hundreds of deaths. The impact was severe in the extremely vulnerable Atlantic forest of Brazil – a biodiversity hotspot that has <a href="https://www.ioes.ucla.edu/wp-content/uploads/Giorgi-F07-fieldreport-FIN.pdf">shrunk to 7%</a> of its original forest cover. </p>
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<img alt="" src="https://images.theconversation.com/files/343340/original/file-20200622-55017-1f4z10r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/343340/original/file-20200622-55017-1f4z10r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/343340/original/file-20200622-55017-1f4z10r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/343340/original/file-20200622-55017-1f4z10r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/343340/original/file-20200622-55017-1f4z10r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/343340/original/file-20200622-55017-1f4z10r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/343340/original/file-20200622-55017-1f4z10r.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">Veterinarians inspect monkeys found dead in Brazil, where primates are suspected of spreading yellow fever.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/veterinarians-examine-dead-monkeys-at-the-municipal-news-photo/916257726">Carl de Souza/AFP via Getty Images</a></span>
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<p>Shrinking habitat has been <a href="https://doi.org/10.1002/ajp.23089">shown to concentrate howler monkeys</a> – one of the main South American yellow fever hosts. A study on primate density in Kenya further demonstrated that forest fragmentation led a greater density of primates, which in turn <a href="http://doi.org/10.1111/j.1365-2656.2008.01481.x">led to pathogens becoming more prevalent</a>. </p>
<p>Deforestation resulted in patches of forest that both concentrated the primate hosts and favored the mosquitoes that could transmit the virus to humans. </p>
<h2>Malaria: Humans can also infect wildlife</h2>
<p>Just as wildlife pathogens can jump to humans, humans can cross-infect wildlife. </p>
<p>Falciparum malaria kills hundreds of thousands of people yearly, especially in Africa. But in the Atlantic tropical forest of Brazil, we have also found a surprisingly high rate of <em>Plasmodium falciparum</em> (the malaria parasite responsible for severe malaria) circulating <a href="http://doi.org/10.1186/s12936-015-0680-9">in the absence of humans</a>. That raises the possibility that this parasite may be infecting <a href="http://www.nhc.ed.ac.uk/index.php?page=493.166.504.508.511">new world monkeys</a>. Elsewhere in the Amazon, monkey species have <a href="http://doi.org/10.1186/1475-2875-12-180">become naturally infected</a>. In both cases, deforestation could have facilitated cross-infection.</p>
<p>We and other scientists have extensively documented the <a href="https://doi.org/10.4269/ajtmh.2006.74.3">associations between deforestation</a> <a href="http://doi.org/10.1073/pnas.1905315116">and malaria</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3757555/">in the Amazon</a>, showing how the malaria-carrying mosquitoes and human malaria cases are <a href="http://doi.org/10.1371/journal.pone.0085725">strongly linked</a> <a href="http://doi.org/10.1590/0074-02760170522">to deforested habitat</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/343339/original/file-20200622-54981-ass960.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/343339/original/file-20200622-54981-ass960.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/343339/original/file-20200622-54981-ass960.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/343339/original/file-20200622-54981-ass960.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/343339/original/file-20200622-54981-ass960.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/343339/original/file-20200622-54981-ass960.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/343339/original/file-20200622-54981-ass960.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">Children in Ethiopia read under mosquito netting, used to protect people from mosquitoes that transmit malaria.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/in-ambowuha-birtukan-demissie-reads-to-her-siblings-before-news-photo/585855656?adppopup=true">Louise Gubb/Corbis via Getty Images</a></span>
</figcaption>
</figure>
<p>Another type of malaria, <em>Plasmodium knowlesi</em>, known to circulate among monkeys, <a href="https://doi.org/10.1016/S0140-6736(04)15836-4">became a concern to human health</a> over a decade ago in Southeast Asia. Several studies have shown that areas sustaining higher rates of forest loss also had <a href="http://doi.org/10.3201/eid2202.150656">higher rates of human infections</a>, and that the mosquito vectors and monkey hosts spanned a wide range of habitats <a href="http://doi.org/10.1186/s13071-016-1527-0">including disturbed forest</a>.</p>
<h2>Venezuelan equine encephalitis: Rodents move in</h2>
<p>Venezuelan equine encephalitis is another mosquito-borne virus that is estimated to cause tens to hundreds of thousands of humans to develop febrile illnesses every year. Severe infections can lead to encephalitis and even death. </p>
<p>In the Darien province of Panama, we found that two rodent species had particularly high rates of infection with Venezuelan equine encephalitis virus, leading us to suspect that <a href="https://doi.org/10.1371/journal.pntd.0004554">these species may be the wildlife hosts</a>. </p>
<p>One of the species, Tome’s spiny rat, has also been <a href="http://doi.org/10.3201/eid1105.041251">implicated in other studies</a>. The other, the short-tailed cane mouse, is also involved in the transmission of zoonotic diseases such as hantavirus and possibly Madariaga virus, an emergent encephalitis virus. </p>
<p>While <a href="http://doi.org/10.1017/S0266467498000509">Tome’s spiny rat</a> is widely found in tropical forests in the Americas, it <a href="https://doi.org/10.1644/1545-1542(2000)081%3C0070:MUBATF%3E2.0.CO;2">readily occupies regrowth and forest fragments</a>. The <a href="https://animaldiversity.org/accounts/Zygodontomys_brevicauda/">short-tailed cane mouse</a> prefers habitat on the edge of forests and abutting cattle pastures. </p>
<p>As deforestation in this region progresses, these two rodents can occupy forest fragments, cattle pastures and the regrowth that arises when fields lie fallow. <a href="http://doi.org/10.1038/s41598-017-07476-2">Mosquitoes also occupy these areas</a> and can bring the virus to humans and livestock.</p>
<h2>Ebola: Disease at the forest’s edge</h2>
<p>Vector-borne diseases are not the only zoonoses sensitive to deforestation. Ebola was first described in 1976, but outbreaks have become more common. The <a href="https://www.cdc.gov/vhf/ebola/history/2014-2016-outbreak/index.html">2014-2016 outbreak</a> killed more than 11,000 people in West Africa and drew attention to diseases that can spread from wildlife to humans. </p>
<p>The natural transmission cycle of the Ebola virus remains elusive. Bats have been implicated, with possible additional ground-dwelling animals maintaining “silent” transmission between human outbreaks. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/343343/original/file-20200622-54985-143xodx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/343343/original/file-20200622-54985-143xodx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=394&fit=crop&dpr=1 600w, https://images.theconversation.com/files/343343/original/file-20200622-54985-143xodx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=394&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/343343/original/file-20200622-54985-143xodx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=394&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/343343/original/file-20200622-54985-143xodx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/343343/original/file-20200622-54985-143xodx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/343343/original/file-20200622-54985-143xodx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Bats, sometimes eaten as food, have been suspected of spreading Ebola.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/ugandan-man-displays-a-bat-he-captured-for-food-december-1-news-photo/1320445">Tyler Hicks/Getty Images</a></span>
</figcaption>
</figure>
<p>While the exact nature of transmission is not yet known, several studies have shown that deforestation and forest fragmentation were <a href="https://doi.org/10.1038/s41598-017-14727-9">associated with outbreaks</a> <a href="https://doi.org/10.1038/srep41613">between 2004 and 2014</a>. In addition to possibly concentrating Ebola wildlife hosts, fragmentation may serve as a <a href="http://doi.org/10.1590/0074-0276140417">corridor for pathogen-carrying animals</a> to spread the virus over large areas, and it may increase human contact with these animals along the forest edge.</p>
<h2>What about the coronavirus?</h2>
<p>While the origin of the SARS-CoV-2 outbreak hasn’t been proved, a <a href="https://doi.org/10.1038/s41591-020-0820-9">genetically similar virus</a> has been detected in <a href="http://doi.org/10.1016/j.cub.2020.03.022">intermediate horseshoe bats and</a> <a href="https://doi.org/10.1038/s41586-020-2169-0">Sunda pangolins</a>.</p>
<p>The range of the Sunda pangolin – which is critically endangered – overlaps with the <a href="https://doi.org/10.1046/j.1365-2699.2000.00381.x">intermediate horseshoe bat</a> in the forests of Southeast Asia, where it lives in mature tree hollows. As forest habitat shrinks, could pangolins also experience increased density and susceptibility to pathogens? </p>
<p>In fact, in small <a href="https://doi.org/10.1002/ece3.4632">urban forest fragments</a> in Malaysia, the Sunda pangolin was detected even though overall mammal diversity was much lower than a comparison tract of contiguous forest. This shows that this animal is able to persist in fragmented forests where it could increase contact with humans or other animals that can harbor potentially zoonotic viruses, such as bats. The Sunda pangolin is poached for its meat, skin and scales and imported illegally from Malaysia and Vietnam into China. A wet market in Wuhan that sells such animals has been <a href="https://doi.org/10.1016/j.meegid.2020.104384">suspected as a source</a> of the current pandemic.</p>
<h2>Preventing zoonotic spillover</h2>
<p>There is still a lot that we don’t know about how viruses jump from wildlife to humans and what might drive that contact. </p>
<p>Forest fragments and their associated landscapes encompassing forest edge, agricultural fields and pastures have been a repeated theme in tropical zoonoses. While many species disappear as forests are cleared, others have been able to adapt. Those that adapt may become more concentrated, increasing the rate of infections. </p>
<p>Given the evidence, it is clear humans need to balance the production of food, forest commodities and other goods with the protection of tropical forests. Conservation of wildlife may keep their pathogens in check, preventing zoonotic spillover, and ultimately benefiting humans, too.</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/139645/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amy Y. Vittor receives funding from the National Institutes of Health. She is affiliated with the group Florida Clinicians for Climate Action as a steering committee member. </span></em></p><p class="fine-print"><em><span>Gabriel Zorello Laporta receives funding from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
grant n. 307432/2019-0) and received funding from the São Paulo Research Foundation (FAPESP grant n. 2014/09774-1). </span></em></p><p class="fine-print"><em><span>Maria Anice Mureb Sallum receives funding from Fundação de Amparo à Pesquisa do Estado de São Paulo, FAPESP # 2014/26229-7, and Conselho Nacional de Pesquisa, CNPq # 301877/2016-5. </span></em></p>Yellow fever, malaria and Ebola all spilled over from animals to humans at the edges of tropical forests. The new coronavirus is the latest zoonosis.Amy Y. Vittor, Assistant Professor of Medicine, University of FloridaGabriel Zorello Laporta, Professor of biology and infectious diseases, Faculdade de Medicina do ABCMaria Anice Mureb Sallum, Professor of Epidemiology, Universidade de São Paulo (USP)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1375022020-04-30T15:56:53Z2020-04-30T15:56:53ZWhy a campaign to champion all vaccines matters now more than ever<figure><img src="https://images.theconversation.com/files/331369/original/file-20200429-51513-9xywtf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Vaccines are some of the most equitable and cost-effective health interventions available.
</span> <span class="attribution"><span class="source"> ranplett/GettyImages</span></span></figcaption></figure><p><a href="https://www.who.int/news-room/campaigns/world-immunization-week/world-immunization-week-2020">World Immunisation Week</a> is celebrated in the last week of April every year. The aim is to recognise efforts to develop new vaccines and increase vaccination coverage worldwide. The World Health Organisation (WHO) also uses the week to galvanise national and international communities to keep pushing for more: greater demand for vaccines, better access, equity and higher coverage.</p>
<p>Vaccines are some of the most equitable and cost-effective health interventions available. As global attention is captured by the COVID-19 pandemic, the campaign to champion all vaccines matters now more than ever.</p>
<h2>Lives saved due to immunisation</h2>
<p>The world before vaccination was a very different place. On the African continent, before a <a href="https://www.afro.who.int/health-topics/yellow-fever">yellow fever</a> vaccine was developed and routinely delivered (as recommended by the WHO in 1988), epidemics occurred every three to 10 years. Up to a quarter of those showing symptoms would get severe disease and among those with severe disease, half would die. Outbreaks still occur in at-risk areas where vaccination services have broken down. But if the vaccine is available, 99% of people who get it are protected within 30 days of the injection and will survive.</p>
<p>Similarly with measles, between 2000 and 2018 the vaccination is estimated to have prevented <a href="https://www.who.int/news-room/fact-sheets/detail/measles">23 million deaths</a> worldwide. In the 1960s, before widespread vaccination, measles epidemics used to occur every two or three years, not only causing millions of deaths, usually in children, but also long-term disabilities. Measles can attack every organ in the body, and even after recovering from the illness, children can be left blind or deaf, with <a href="https://science.sciencemag.org/content/366/6465/599">detrimental effects</a> on their immune systems. </p>
<p>There have been substantial gains in measles prevention. But there were still 140,000 measles <a href="https://www.who.int/news-room/detail/05-12-2019-more-than-140-000-die-from-measles-as-cases-surge-worldwide">deaths</a> worldwide in 2018 due to pockets of unvaccinated children transmitting the disease. In the African region alone, the WHO <a href="https://www.who.int/news-room/detail/05-12-2019-more-than-140-000-die-from-measles-as-cases-surge-worldwide">estimates</a> there were 1.7 million cases of illness and 50,000 deaths in 2018 . </p>
<p>While calling for a COVID-19 vaccine we must remember to ensure that the highly effective vaccines in our existing armoury, like the one for measles, continue to be made available for all who need them. COVID-19 provides a stark reminder of what a world without vaccines would look like.</p>
<h2>Limitations</h2>
<p>If vaccines are so effective, why don’t we have them for all diseases?</p>
<p>HIV and malaria are “hard hitters” on the African continent and have been for decades, so why are there still no vaccines available? </p>
<p>A large part of the challenge boils down to how rapidly these germs can change their identity. Vaccines aim to simulate a natural infection, so that when a true infection comes along, your body can recognise the germ quickly and launch the correct response to disarm it. They are, in that way, one of the most “natural” medical interventions you could think of. Essentially they just prepare your own immune system to react more effectively than it would if coming into contact with the germ for the very first time.</p>
<p>The route to developing an effective vaccine, therefore, depends on the nature of the germ itself, how your natural immune system responds to it and the safety of different possible types of vaccine material. Unfortunately, both malaria and HIV are highly complex organisms that can rapidly change the way they “look” to your immune system. This makes it hard to make a vaccine, as the organism itself is constantly changing and has inbuilt ways to evade recognition by your immune system.</p>
<p>The safety of potential vaccines is also crucial. Research moves sequentially from “test-tubes” to animals and, if it meets all the criteria indicating that it is safe, then the trials move to include a small number of healthy adults. Gradually, the number and diversity of those included in trials is expanded, until enough safety and efficacy data are accrued to pass it through to the next stage of development. </p>
<p>There is a huge amount of ongoing research to identify possible “candidate” vaccines for both HIV and malaria (and COVID-19). A few malaria vaccine candidates have looked promising and there is a large scale implementation trial of the <a href="https://www.malariavaccine.org/malaria-and-vaccines/rtss">RTSS malaria vaccine</a> to demonstrate effectiveness; researchers are <a href="https://www.tandfonline.com/doi/abs/10.1080/14760584.2019.1561289?journalCode=ierv20&">optimistic</a>. Despite testing a large number of HIV vaccine candidates in the past few decades, they have failed to demonstrate efficacy, and the search continues. </p>
<p>But the frustration from decades of failed attempts should not reduce the rigour of the research needed. The vaccine development process has to be long enough to ensure the end product is safe. Continued focus on developing new vaccines is needed, alongside patience and political will to get them to the populations that need them most when they do become available.</p>
<h2>Remaining challenges: access and attitudes</h2>
<p>“Getting vaccines to the populations that need them most” encompasses a range of problems. The WHO <a href="https://www.who.int/news-room/fact-sheets/detail/immunization-coverage">estimates</a> that in 2018, 20 million children remained unvaccinated or under-vaccinated. That is, they had not completed the full course of recommended vaccinations by the time they reached one year of age. That is one in every seven infants worldwide. </p>
<p>This statistic hides considerable complexity. The number varies by vaccine, across countries and within countries.</p>
<p>Leaving a proportion of the population under-vaccinated doesn’t just affect those individuals, it reduces herd protection. Herd protection is the effect achieved by vaccinating most people in the “herd” and therefore reducing transmission of the infection to such an extent that the remainder don’t come into contact with it. This protects vulnerable people who cannot be vaccinated because they are too young or have certain health conditions. </p>
<p>Pockets of under-vaccinated people put themselves and others at risk as they act as reservoirs for transmission of the infection.</p>
<p>Vaccine hesitancy or “anti-vax” sentiment has become a growing issue, to the extent that the WHO considered it one of the <a href="https://www.who.int/news-room/feature-stories/ten-threats-to-global-health-in-2019">top 10 threats to global health in 2019</a>. It is still relatively rare in Africa, but it has arisen recently in populations more sceptical of health authorities and for whom the memories of uncontrolled infection have disappeared. </p>
<p>It must be guarded against, especially in the uncertain times of COVID-19. A global pandemic like this one threatens to reverse the victories that are won every day over vaccine-preventable diseases in low-income settings, including gains towards <a href="https://www.sciencemag.org/news/2020/04/polio-measles-other-diseases-set-surge-covid-19-forces-suspension-vaccination-campaigns">polio eradication</a>. </p>
<p>The pandemic reduces the staff and resources available to continue routine immunisation services as resources are redirected to COVID-19 wards. Uncertainty over whether services are continuing as many workplaces are temporarily shut down, together with reduced transport options, makes it harder for parents to access care. </p>
<p>Fear of contracting the virus in transit or while at the health facility may additionally prevent parents from bringing children to the health centre. If the uptake of vaccines does drop, outbreaks of vaccine preventable diseases such as bacterial meningitis and pneumonia, measles, rotavirus diarrhoea and others will cause even higher rates of death when patients present to a health system that is already straining under the weight of COVID. </p>
<p>Now more than ever, routine vaccination must continue. The WHO has released <a href="https://www.who.int/immunization/news_guidance_immunization_services_during_COVID-19/en/">guidelines</a> on maintaining routine immunisation services during the COVID-19 pandemic. While everyone has their eyes on the coronavirus pandemic, it is vitally important that national immunisation programmes, front line health workers and parents find a way to sustain the routine immunisation system and continue to save millions of children’s lives.</p><img src="https://counter.theconversation.com/content/137502/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Katherine E. Gallagher receives funding from the Bill & Melinda Gates Foundation and the United Kingdom National Institute for Health Research. </span></em></p><p class="fine-print"><em><span>I have received funding for vaccine related research from Gavi, The Vaccine Alliance; the Bill & Melinda Gates Foundation; The Wellcome Trust; The Medical Research Council of the UK; the National Institute of Health Research; PATH Vaccine Solutions.
</span></em></p><p class="fine-print"><em><span>Ifedayo Adetifa receives funding from the following: United Kingdom's Medical Research Council, Department for International Development and National Institute for Health Research, and from Gavi, The Vaccine Alliance. </span></em></p><p class="fine-print"><em><span>John Ojal receives funding from National Institute for Health Research (NIHR) Global Health Research Unit on Mucosal Pathogens using UK aid from the UK Government.</span></em></p><p class="fine-print"><em><span>Shirine Voller is Programme Manager on a project funded by Gavi, the Vaccine Alliance </span></em></p><p class="fine-print"><em><span>Wangeci Kagucia is a co-investigator on a project funded by Gavi, The Vaccine Alliance. </span></em></p>Coronavirus is a stark reminder of what a world without vaccines would look like.Katherine E. Gallagher, Assistant Professor of Epidemiology, London School of Hygiene & Tropical MedicineAnthony Scott, Professor of Vaccine Epidemiology, Director HPRU in Immunisation, London School of Hygiene & Tropical MedicineIfedayo Adetifa, Associate Professor, London School of Hygiene and Tropical Medicine, United Kingdom & Clinical Epidemiologist, KEMRI Wellcome Trust Research ProgrammeJohn Ojal, Research Fellow in Infectious Disease Modelling, NIHR Mucosal Pathogens Research Unit, London School of Hygiene & Tropical MedicineShirine Voller, ED Programme Manager, KEMRI Wellcome Trust Research ProgrammeWangeci Kagucia, Research Fellow, KEMRI Wellcome Trust Research ProgrammeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1342972020-03-23T12:02:35Z2020-03-23T12:02:35ZHow one federal agency took care of its workers during the yellow fever pandemic in the 1790s<figure><img src="https://images.theconversation.com/files/322027/original/file-20200320-22627-htg18q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sen. Mitt Romney, R-Utah, at a Senate GOP lunch meeting on March 20, 2020, to discuss the 'phase 3' coronavirus stimulus bill. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/sen-mitt-romney-speaks-as-he-attends-a-senate-gop-lunch-news-photo/1207849533?adppopup=true">Getty/ Drew Angerer</a></span></figcaption></figure><p><a href="https://blogs.loc.gov/law/2020/03/coronavirus-resource-guide/">U.S. lawmakers are debating strategies</a> to stem the economic impact of the coronavirus. With <a href="https://www.wsj.com/articles/call-it-a-layoff-a-furlough-or-a-cut-shift-americans-are-losing-work-11584550057">businesses across the country cutting back hours or closing</a>, the pandemic has exposed the vulnerability of wage workers. </p>
<p>Congress is responding with <a href="https://www.cnn.com/2020/03/18/politics/coronavirus-congress-relief-senate-house/index.html">unprecedented legislation</a>, which <a href="https://ap.gilderlehrman.org/essays/hundred-days-and-beyond-what-did-new-deal-accomplish">echoes New Deal programs of the 1930s</a>. But the historical echoes extend much farther back, all the way to the first public health crisis in this country.</p>
<h2>Fever pains in the early republic</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/322010/original/file-20200320-22594-1bsyqsg.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/322010/original/file-20200320-22594-1bsyqsg.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/322010/original/file-20200320-22594-1bsyqsg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=997&fit=crop&dpr=1 600w, https://images.theconversation.com/files/322010/original/file-20200320-22594-1bsyqsg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=997&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/322010/original/file-20200320-22594-1bsyqsg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=997&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/322010/original/file-20200320-22594-1bsyqsg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1252&fit=crop&dpr=1 754w, https://images.theconversation.com/files/322010/original/file-20200320-22594-1bsyqsg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1252&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/322010/original/file-20200320-22594-1bsyqsg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1252&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Prominent Philadelphia physician Dr. Benjamin Rush wrote about his approach to treating yellow fever patients during the epidemic.</span>
<span class="attribution"><a class="source" href="https://www.nlm.nih.gov/exhibition/politicsofyellowfever/collection-detail.html?imgid=2&imgName=OB12591-md">The National Library of Medicine</a></span>
</figcaption>
</figure>
<p><a href="https://sju.academia.edu/JuliaMansfield">As a historian of infectious disease</a>, I see familiar patterns emerging in this pandemic that date back to the early republic. In the 1790s, <a href="https://www.cambridge.org/us/academic/subjects/history/regional-history-after-1500/mosquito-empires-ecology-and-war-greater-caribbean-16201914?format=PB&isbn=9780521459105">yellow fever became epidemic in the Caribbean islands</a> and grew into a pandemic that reached the United States, Spain and Italy. <a href="https://www.upenn.edu/pennpress/book/1520.html">It appeared in the U.S. capital, Philadelphia, in 1793</a>, five years after the ratification of the U.S. Constitution. </p>
<p>For the next decade, yellow fever erupted sporadically in Philadelphia and other populous coastal cities and towns. The outbreaks shut down businesses, suspended court sessions, and drove residents to flee. </p>
<p>During the first outbreak of 1793, a flour miller summed up the experience with these words: “I want to be doing something, but the Fever in Philadelphia has thrown us all out of our Geers.” </p>
<p>The pandemic forced Americans to tackle some of the questions that have surfaced in the past week: Would some people risk exposure to the virus in order to earn wages? Should employers allow workers to stay away from their jobs because of the risk of infection? How would families who relied on daily or weekly wages pull through? </p>
<p>Neither state nor federal lawmakers tried to answer these questions in the 1790s. But federal agencies had to respond as employers. The United States Mint, <a href="https://www.usmint.gov/learn/history/overview">which produced the young nation’s coinage</a>, devised the most effective response.</p>
<h2>Protecting workers in a pandemic</h2>
<p>To protect the currency supply, the director of the U.S. Mint in Philadelphia suspended operations during each outbreak of yellow fever. Letters in the Mint’s archive show that he put workers on furlough with a guarantee of half pay for the two to three months that yellow fever lasted. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/322024/original/file-20200320-22618-132t1pb.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/322024/original/file-20200320-22618-132t1pb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/322024/original/file-20200320-22618-132t1pb.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=274&fit=crop&dpr=1 600w, https://images.theconversation.com/files/322024/original/file-20200320-22618-132t1pb.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=274&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/322024/original/file-20200320-22618-132t1pb.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=274&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/322024/original/file-20200320-22618-132t1pb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=344&fit=crop&dpr=1 754w, https://images.theconversation.com/files/322024/original/file-20200320-22618-132t1pb.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=344&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/322024/original/file-20200320-22618-132t1pb.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=344&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 copper penny produced in 1793 by workers at the U.S. Mint in Philadelphia.</span>
<span class="attribution"><a class="source" href="https://www.usmint.gov/learn/history/us-circulating-coins">The U.S. Mint</a></span>
</figcaption>
</figure>
<p>This policy became the Mint’s standard response to yellow fever and was applied six times over eight years.</p>
<p>Most workers received their pay after the outbreak, but highly skilled workers at the rank of officer could obtain their full quarterly pay in advance. Then, as now, the financial pains of a pandemic did not hit all classes equally. </p>
<p>The U.S. Mint’s response to yellow fever struck a balance between workers’ and employers’ needs. Workers put on furlough were guaranteed jobs when the public health crisis was over. Meanwhile, the Mint secured their loyalty by promising back pay, so it was able to resume operations quickly after each outbreak. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/322035/original/file-20200320-22622-1aepddr.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/322035/original/file-20200320-22622-1aepddr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/322035/original/file-20200320-22622-1aepddr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/322035/original/file-20200320-22622-1aepddr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/322035/original/file-20200320-22622-1aepddr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/322035/original/file-20200320-22622-1aepddr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/322035/original/file-20200320-22622-1aepddr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/322035/original/file-20200320-22622-1aepddr.png?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">An artist’s rendition of the first Mint in Philadelphia.</span>
<span class="attribution"><a class="source" href="https://www.usmint.gov/learn/history/overview">The U.S. Mint</a></span>
</figcaption>
</figure>
<p>Today, once again, business leaders and politicians are compelled to respond to a pandemic. State and federal legislators are taking bold steps to counter anxiety with assurances of stability. And they are developing new safety nets for workers made vulnerable by the coronavirus. As lawmakers consider their options, there are lessons to be found in U.S. history about sustaining workers during a public health crisis.</p>
<p>[<em>Get facts about coronavirus and the latest research.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=upper-coronavirus-facts">Sign up for our newsletter.</a>]</p><img src="https://counter.theconversation.com/content/134297/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julia Mansfield 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>Today’s coronavirus pandemic has echoes in the yellow fever pandemic of the 1790s. Then, as now, workers struggled with how to support themselves and their families. One federal agency had the answer.Julia Mansfield, Visiting Assistant Professor of History, St. Joseph's UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1201172019-07-23T14:24:44Z2019-07-23T14:24:44ZAfrica needs specialist capacity to tackle the spread of infectious diseases<figure><img src="https://images.theconversation.com/files/285094/original/file-20190722-11350-3gxzf5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Dr Joseph Sempa of SACEMA presenting at the 2019 Clinic on Meaningful Modelling of Epidemiological Data. </span> <span class="attribution"><span class="source">AIMS-South Africa</span></span></figcaption></figure><p>Over the past ten years, a community of practice has begun to develop in Africa around research that uses models to understand and evaluate population-level health problems and their potential solutions. This type of research – known as Applied Epidemiological Modelling – involves developing and applying analytical tools for problems that can’t be addressed by traditional statistical methods. These tools are particularly useful for combating infectious diseases.</p>
<p>This kind of modelling is a complex, multidisciplinary field that has flourished over the past <a href="https://science.sciencemag.org/content/347/6227/aaa4339">15 to 20 years</a>. But most work has been done by researchers based in Europe and North America – far away from the places where infectious diseases pose the biggest threat. This mismatch can lead to imbalances in the focus of research. For example, published papers may focus more on topics of academic interest or popular appeal than on pressing local health issues. </p>
<p>Models have enormous potential to improve how decisions are made about public health in African countries. For example, they have been used to address important questions such as <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(15)70139-8/fulltext">how to evaluate new vaccines</a> and <a href="https://journals.plos.org/plosmedicine/article/authors?id=10.1371/journal.pmed.1002675">how climate change will affect disease vectors</a>. Models can also incorporate economic costs and be used <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(18)30512-7/fulltext">to inform decisions about investing in public health</a>. </p>
<h2>The problem of capacity</h2>
<p>Learning to address such questions is difficult. Students must develop a deep understanding of health issues as well as sophisticated mathematical skills. They must also learn to communicate about their work to policy makers and the public.</p>
<p>Worldwide, the main approach to developing these skills follows the traditional model of postgraduate education. New researchers learn from long-term association with those who have done key work in the field before them. </p>
<p>There are two problems with this approach. First, it is a slow way to transfer skills, with each expert only able to supervise a few students at a time. Second, it is a very localised process: it builds expertise only where it can already be found.</p>
<p>Meanwhile, diseases such as <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">Ebola</a>, <a href="https://www.who.int/csr/don/17-january-2019-measles-madagascar/en/">measles</a> and <a href="https://www.who.int/csr/don/18-april-2019-yellow-fever-brazil/en/">yellow fever</a> continue to spread in areas of the world that lack the expertise to integrate models and data in a way that is useful to inform policy decisions. This means it is necessary to develop local capacity in these methods.</p>
<h2>Making it work</h2>
<p>The traditional approach to capacity development for mathematical modelling, including epidemiological modelling, involves bringing small groups of specialists from developed countries to teach short courses to groups of African students. These typically last for no more than a week and are usually one-off events, or are repeated with new groups of students. </p>
<p>That approach can be useful for imparting technical skills. But it’s not enough to build local capacity. This is because technical skills are not embedded in a broader context of how to approach applied, interdisciplinary research – including working with collaborators trained in different disciplines and communicating results to policy makers. </p>
<p>On top of this, the short-term nature of the interactions means that mentoring and instructional skills development are not emphasised.</p>
<p>Alternative ways of working have been developed. For the past 10 years workshops run under the <a href="http://www.ici3d.org/">International Clinics in Infectious Disease Dynamics</a> programme have helped develop capacity in Applied Epidemiological Modelling on the continent. </p>
<p>We have built workshops – referred to as Clinics – that are very hands-on. These are focused explicitly on communication and on contextualising models within public health questions. At the same time, they are aimed at developing key technical skills. </p>
<p>They also differ from typical workshops by integrating participants from around the world. But, importantly, all clinics have African faculty members who develop and present material. The aim is to make these workshops a true international endeavour, rather than a one-way transfer of knowledge.</p>
<p>Another emphasis has been on helping African participants build networks across geographic and disciplinary borders. Participants come from a wide range of backgrounds, including mathematics, statistics, public health, and epidemiology. And we have created a pipeline that allows some strong participants to eventually develop into workshop faculty.</p>
<p>The programme has two core components. These emphasise the use of data to inform the construction of clear and concise models appropriate to answer a given question. </p>
<p><strong>Meaningful modelling:</strong> the annual <a href="http://www.ici3d.org/mmed">Clinic on Meaningful Modeling of Epidemiological Data</a> exposes participants to a diverse set of modelling approaches that allow them to engage with real-world questions about infectious disease dynamics. Participants learn to integrate mathematical models with epidemiological data. </p>
<p>The Clinic consists of two tracks. One targets quantitative scientists; the other, public health workers. In the second week participants collaborate on research projects, working in interdisciplinary groups. Six weeks after the clinic, they must submit group reports on their work. This gives them real-world experience working in international, interdisciplinary teams to produce a research product.</p>
<p><strong>Health researchers and population biologists:</strong> Another annual Clinic focuses on <a href="http://ici3d.org/daidd">Dynamic Approaches to Infectious Disease Data</a>. It targets public health researchers and population biologists studying infectious diseases. </p>
<p>Instruction focuses on identification of infectious disease research questions that can be usefully addressed using mechanistic models and construction of models tailored to these questions. Participants develop written research proposals for their systems of interest. They also receive guidance to seek out the resources they need for carrying out their proposed research. </p>
<p>Faculty members are from many fields and at different career stages. This ensures that participants have someone to engage with about their current work or future plans; enhances programme sustainability; and builds local capacity in both training and research. And <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001295">innovative teaching and learning techniques developed for the Clinics</a> have even been adapted for <a href="https://www.sciencedirect.com/science/article/pii/S1755436517300920">training students in other parts of the world</a>.</p>
<p><em>Zinhle E. Mthombothi, a Junior Researcher at SACEMA, and Faikah Bruce, a PhD candidate at University of Cape Town and SACEMA, contributed to this article.</em></p><img src="https://counter.theconversation.com/content/120117/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Juliet Pulliam receives funding from the South African Department of Science and Technology-National Research Foundation Centres of Excellence Programme. She is co-director of the International Clinics on Infectious Disease Dynamics and Data (ICI3D) Programme. The programme has received funding from a number of sources including the NIH, NSF, WHO, and SACEMA (<a href="http://www.ici3d.org/funding/">http://www.ici3d.org/funding/</a>)</span></em></p><p class="fine-print"><em><span>Jonathan Dushoff receives funding from the The Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canadian Institutes of Health Research (CIHR). He is co-director of the International Clinics on Infectious Disease Dynamics and Data (ICI3D) Program and a research associate of the South African Centre for Epidemiological Modelling and Analysis (SACEMA). </span></em></p>Applied Epidemiological Modelling has enormous potential to improve how decisions are made about public health in African countries.Juliet Pulliam, Director: SACEMA, South African Centre for Epidemiological Modelling & Analysis (SACEMA) Jonathan Dushoff, Professor of Biology, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1196722019-07-07T09:03:30Z2019-07-07T09:03:30ZSharing data can help prevent public health emergencies in Africa<figure><img src="https://images.theconversation.com/files/282471/original/file-20190703-126360-6ijqvb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Countries can be better prepared and respond faster to disease outbreaks if public health data is shared more freely.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Global collaboration and sharing data on public health emergencies is important to fight the spread of infectious diseases. If scientists and health workers can openly share their data across regions and organisations, countries can be better prepared and respond faster to disease outbreaks.</p>
<p>This was the case in with the <a href="https://www.ncbi.nlm.nih.gov/pubmed/28405027">2014 Ebola outbreak in West Africa</a>. Close to 100 scientists, clinicians, health workers and data analysts from around the world worked together to help contain the spread of the disease. </p>
<p>But there’s a lack of trust when it comes to sharing data in north-south collaborations. African researchers are suspicious that their northern partners could publish data without acknowledging the input from the less resourced southern institutions where the data was first generated. Until recently, the authorship of key scientific publications, based on collaborative work in Africa, was dominated by scientists from outside Africa. </p>
<p>The Global Research Collaboration for Infectious Disease Preparedness, an international network of major research funding organisations, recently published a <a href="http://www.glopid-r.org/new-release-roadmap-to-data-sharing/">roadmap to data sharing</a>. This may go some way to address the data sharing challenges. Members of the network are expected to encourage their grantees to be inclusive and publish their results in open access journals. The network includes major funders of research in Africa like the European Commission, Bill & Melinda Gates Foundation and Wellcome Trust. </p>
<p>The roadmap provides a guide on how funders can accelerate research data sharing by the scientists they fund. It recommends that research funding institutions make real-time, external data sharing a requirement. And that research needs to be part of a multi-disciplinary disease network to advance public health emergencies responses. </p>
<p>In addition, funding should focus on strengthening institutions’ capacity on a number of fronts. This includes data management, improving data policies, building trust and aligning tools for data sharing.</p>
<p>Allowing researchers to freely access data generated by global academic counterparts is critical for rapidly informing disease control strategies in public health emergencies. </p>
<h2>Why share data</h2>
<p>Mounting appropriate and timely responses to emerging and re-emerging infectious diseases requires global cooperation on data analysis across disciplines. Examples include Ebola, Lassa fever and Yellow fever.</p>
<p>During the <a href="https://www.cdc.gov/vhf/ebola/history/2014-2016-outbreak/index.html">2014 Ebola outbreak in West Africa</a>, field and laboratory data collected in real-time were shared between scientists from different countries. These data revealed how the Ebola virus was evolving and spreading in the region. The information was then used to contain the spread of the virus in Guinea, Liberia and Sierra Leone.</p>
<p>Ninety-six individual investigators, including clinicians and scientists, from 60 institutions in 18 countries worked together. They collected and analysed data by sequencing 1,610 Ebola virus genomes. The data informed policy decisions in West Africa because government ministers from Sierra Leone and Liberia were part of the investigators. </p>
<p>The work done in West Africa shows that global data sharing can work.</p>
<p>This north-south collaboration is the research partnership model that the <a href="https://theconversation.com/how-a-partnership-is-closing-the-door-on-parachute-research-in-africa-102217">European and Developing Countries Clinical Trials Partnership</a> uses on the continent. </p>
<p>This is a partnership between the European Union and national institutions in Europe and sub-Saharan Africa. It was initially created in response to the global health crisis caused by HIV/AIDS, tuberculosis and malaria. Now it includes research and responses to neglected and emerging infections. </p>
<p>It currently supports several institutions that were involved in the West African study. As the regional director for Africa, I promote global collaborations that acknowledge inputs from Africa researchers and institutions. </p>
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<em>
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Read more:
<a href="https://theconversation.com/how-a-partnership-is-closing-the-door-on-parachute-research-in-africa-102217">How a partnership is closing the door on "parachute" research in Africa</a>
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<h2>Collaborations</h2>
<p>Our north-south partnership is also making strides to improve the capacity for collaboration and data sharing. </p>
<p>The global research collaboration includes a number of members such as the African Academy of Sciences, the Academy of Scientific Research and Technology in Egypt and the South African Medical Research Council.</p>
<p>There are several initiatives under way. </p>
<p>For one, the African Academy of Sciences is in the early stages of building a <a href="https://aesa.ac.ke/cari/coalition-for-african-research-and-innovation/">Coalition for African Research and Innovation</a>. This platform will foster collaboration on research and innovation in Africa. It will also address the under investment in scientific talent and research infrastructure.</p>
<p>Another example is the <a href="https://pactr.samrc.ac.za/">Pan African Clinical Trials Registry</a>. This is hosted by the South Africa Medical Research Council. The registry provides access to contacts for researchers as well as trial sites. It also provides information on which organisation or institution funds various research projects. This data can be used to map clinical trial activity in several disease conditions relevant to the continent such as Ebola. </p>
<p>In 2017, for example, two public health emergencies networks and four regional networks of excellence were funded. This was to ensure that African countries are better prepared to prevent, respond to and minimise the impact of infectious disease outbreaks. </p>
<h2>Building partnerships</h2>
<p>Collaboration and data sharing has become a serious focus in the fight against public health emergencies. </p>
<p>Funding agencies, ethics and regulatory bodies in Africa, reviewers and grant recipients have been looking for ways to consolidate a efforts for collaboration and data sharing. </p>
<p>Among the issues that need to be addressed are big data, the way that databases can be managed and the implementation of systemic reviews. This is critical to prevent the next epidemic.</p>
<p>What the Ebola crisis in West Africa has shown us is that wide scale collaboration is helpful and works. The Global Research Collaboration roadmap instils confidence for such inclusiveness.</p><img src="https://counter.theconversation.com/content/119672/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Moses John Bockarie works for EDCTP which is funded by the European Commission. In addition to his honorary appointment at the South African Medical Research Council, he is also a honorary professor in the Department of Medicine, University of Cape Town, South Africa. He previously received funding from the UK Department for International Development</span></em></p>Sharing data openly across regions and organisations can help to accelerate preparedness and responses to public health emergencies.Moses John Bockarie, Honorary Chief Specialist Scientist, South African Medical Research CouncilLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1055502018-12-04T11:33:13Z2018-12-04T11:33:13ZOpening up research labs with modified mosquitoes to the community<figure><img src="https://images.theconversation.com/files/244375/original/file-20181107-74757-1b7ob0j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">View of Taichung City, Taiwan, behind a mosquito net. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/view-mosquito-net-taichung-city-taiwan-662487235?src=eoF5QMrNkj4UaA26ScSy2A-4-8">Alan Picard / Shutterstock.com</a></span></figcaption></figure><p>By bringing people close to disease-spreading insects, might we improve public health?</p>
<p>Because they spread malaria, Zika, West Nile, dengue, yellow fever and other diseases, mosquitoes are <a href="https://www.smithsonianmag.com/innovation/kill-all-mosquitos-180959069/">responsible for more human deaths than any other organism</a>. Some of these diseases flourish in tropical regions like sub-Saharan Africa that are urbanizing rapidly and feeling the effects of climate change. Research indicates that <a href="https://doi.org/10.1016/j.jclepro.2017.12.144">temperature increases</a> lead to mosquitoes breeding more frequently, living longer and biting more often. </p>
<p>Meanwhile, advances in scientific research are leading to new approaches to mosquito control. These include <a href="https://www.newyorker.com/magazine/2012/07/09/the-mosquito-solution">genetic</a> <a href="https://www.scientificamerican.com/article/the-wipeout-gene/">modification</a> of male mosquitoes, leading to sterile offspring. Scientists are also exploring the <a href="http://doi.org/10.1016/j.pt.2015.10.011">use of bacteria such as <em>Wolbachia</em></a> to limit the ability of mosquitoes to spread disease. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/244382/original/file-20181107-74766-n4vd3g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/244382/original/file-20181107-74766-n4vd3g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/244382/original/file-20181107-74766-n4vd3g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/244382/original/file-20181107-74766-n4vd3g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/244382/original/file-20181107-74766-n4vd3g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/244382/original/file-20181107-74766-n4vd3g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/244382/original/file-20181107-74766-n4vd3g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/244382/original/file-20181107-74766-n4vd3g.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">Mosquito research facilities are often cloaked in secrecy which breeds distrust among the public.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/mosquito-testing-center-infected-germs-628430486">Aomboon / Shutterstock.com</a></span>
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<p>But mosquito research faces one enormous challenge: a lack of community engagement around this science leads to the <a href="https://theconversation.com/gene-drives-may-cause-a-revolution-but-safeguards-and-public-engagement-are-needed-77012">public feeling anxiety and mistrust</a>. Negative public opinion has the potential to derail this research and associated efforts, such as release of genetically modified mosquitoes in cities. My colleague John Bauer, assistant dean for the UC San Diego Division of Biological Sciences, noted to me that scientists work in high security buildings that the public are banned from entering and then wonder why they are so misunderstood. </p>
<p>I am a professor of architecture at the University of Oregon and am involved in an effort to re-imagine these mosquito research facilities and make them accessible to the public. In an effort to do so we have convened teams of designers, artists and scientists to rethink the design of mosquito research sites so that they include spaces of community engagement. </p>
<h2>Making genetic research transparent</h2>
<p>I have long worked at the <a href="http://www.worldcat.org/title/ecology-and-the-architectural-imagination/oclc/854611173">intersection of people and the environment</a>. I am now working together with <a href="http://www.michaelsinger.com">artist Michael Singer</a>, <a href="https://www.researchgate.net/profile/Mark_Benedict2">Mark Benedict</a> of the Centers for Disease Control and Prevention’s Entomology Branch, <a href="https://ihi.or.tz/staff/dr-fredros-okumu">Fredros Okumu</a> from Tanzania-based <a href="https://ihi.or.tz">Ifakara Health Institute</a> (IHI), and scholars and scientists from the U.K. and U.S., on the “Protective Atmospheres” project to redesign these facilities. </p>
<p>This has the potential to be a game-changing effort. Our hope is that opening up the facility will lead to greater acceptance of this work and lead to better health outcomes. My collaborators and I are not aware of any similar effort meant to integrate research facilities and the community in order to make science approachable.</p>
<p>This is where effective design comes in. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/245814/original/file-20181115-194513-1vieixh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/245814/original/file-20181115-194513-1vieixh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/245814/original/file-20181115-194513-1vieixh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=285&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245814/original/file-20181115-194513-1vieixh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=285&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245814/original/file-20181115-194513-1vieixh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=285&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245814/original/file-20181115-194513-1vieixh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=358&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245814/original/file-20181115-194513-1vieixh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=358&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245814/original/file-20181115-194513-1vieixh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=358&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An artist rendition of a research facility integrated with the community.</span>
<span class="attribution"><span class="source">Brook Muller</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/245815/original/file-20181115-194513-16c7sg0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/245815/original/file-20181115-194513-16c7sg0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/245815/original/file-20181115-194513-16c7sg0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=160&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245815/original/file-20181115-194513-16c7sg0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=160&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245815/original/file-20181115-194513-16c7sg0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=160&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245815/original/file-20181115-194513-16c7sg0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=201&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245815/original/file-20181115-194513-16c7sg0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=201&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245815/original/file-20181115-194513-16c7sg0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=201&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Integrating labs with open fields may reduce the fear factor surrounding mosquito research.</span>
<span class="attribution"><span class="source">Brook Muller</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>What if “arthropod containment” labs with strict biosecurity standards where scientists work with pathogen-carrying mosquitoes are not located at the “back of house” as is typical now. While ensuring that these standards are met, could labs be brought out of the darkness and placed alongside spaces where visitors to these facilities are allowed to go? </p>
<p>Could people walk through protective enclosures alongside or within “mosquito cities,” large spaces of experimentation that are open-air yet netted and that include trees and other outdoor elements allowing controlled study of mosquito populations in quasi-natural conditions? </p>
<p>Could spaces be included that help people understand how to modify their homes to decrease chances they will get bitten? What about recreational spaces such as the tennis court that Okumu hopes to build at Ifakara as a way to make IHI’s research a part of everyday community life? These are some of the questions we are addressing as part of the Protective Atmospheres project. </p>
<h2>Integrating scientists and the community</h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/245849/original/file-20181115-194497-ciunx.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/245849/original/file-20181115-194497-ciunx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/245849/original/file-20181115-194497-ciunx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245849/original/file-20181115-194497-ciunx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245849/original/file-20181115-194497-ciunx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245849/original/file-20181115-194497-ciunx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=480&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245849/original/file-20181115-194497-ciunx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=480&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245849/original/file-20181115-194497-ciunx.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=480&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mosquito City Vision. The goal is not just to mix communities and lab and research facilities. Muller wants the scientists to engage with the local people over normal recreation and participate in daily life.</span>
<span class="attribution"><span class="source">Brook Muller</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Creating interactive facilities that promote public engagement and understanding while adhering to biosafety regulations requires a two-way conversation. Architects and artists must learn from scientists. As one example, they must understand that keeping mosquitoes alive in captivity is difficult. Or that for <em>Anopheles</em>, a genus of mosquito carrying malaria, the setting sun and low light triggers swarm behavior and mating. For a mosquito city built to study swarming behavior, it’s best to orient it toward the sun, and let the romance begin. </p>
<p>And scientists can learn from architects and artists that buildings can tell stories. A walk through a research facility may also be an educational journey through the scientific process along a continuum from genetic engineering to containment to release. By the time a visitor arrives at a mosquito release site at the journey’s end, it may no longer seems so dangerous. Perhaps at that point, visitors actually participate in the release event.</p>
<p>The Protective Atmospheres project is in its infancy, and yet we are hopeful that it has the potential to transform perceptions. It can make scientific activity transparent and encourage the role of citizenry in biological research. It might also change understandings of mosquitoes themselves – for mosquitoes do not kill, they just host organisms that do. </p>
<p>The end game of course is to build one of these facilities. When we do, we hope that children – and others – line up to visit. Concept shifts to reality when members of the Michael Singer Studio and I travel to the Ifakara Health Institute in early 2019 to begin the development of a master plan for their complex. It will include a tennis court.</p><img src="https://counter.theconversation.com/content/105550/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brook Muller works for the University of Oregon. </span></em></p>Genetically modified mosquitoes breed fear and suspicion, especially since the research happens behind closed doors, away from the public. Now scientists and architects are trying to change that model.Brook Muller, Professor of Architecture and Environment, University of OregonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/947472018-07-03T01:45:46Z2018-07-03T01:45:46ZHumans are to blame for the rise in dangerous viral infections<p>Today, we hear about dangerous viral infections around the world on a regular basis. Social media and internet access may be an obvious explanation for their seeming increase.</p>
<p>But it doesn’t just seem this way. The number of viruses and the infections they cause are truly increasing. Scientific advances, the way humans live today and virus biology all contribute to the rise of viruses.</p>
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<strong>
Read more:
<a href="https://theconversation.com/health-check-when-are-we-most-likely-to-catch-viral-diseases-36555">Health Check: when are we most likely to catch viral diseases?</a>
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<h2>New viruses, all the time</h2>
<p>It seems viral infections are everywhere these days. Starting from January 2018, Nigeria has been experiencing an unusually large outbreak of haemorrhagic fever caused by <a href="http://www.who.int/csr/don/20-april-2018-lassa-fever-nigeria/en/">Lassa virus</a>. There have been more than 400 confirmed infections and 100 deaths to date. </p>
<p>The southern Indian state of Kerala is battling an outbreak of the rare <a href="http://www.who.int/news-room/fact-sheets/detail/nipah-virus">Nipah virus</a>, which causes severe inflammation of the brain and claimed the <a href="https://indianexpress.com/article/india/nipah-death-toll-rises-to-14-in-kerala-two-more-cases-confirmed-5193201/">lives of 14 people</a> in May. </p>
<p>The Brazilian outbreak of viral <a href="http://www.who.int/csr/don/09-march-2018-yellow-fever-brazil/en/">yellow fever</a> that began in late 2017 has moved into highly populated areas near São Paulo and Rio de Janeiro. One-third of the 723 people with confirmed infections have so far died from the illness.</p>
<p>We’re no doubt more aware of such serious diseases after the unprecedented 2014-2016 <a href="https://www.bmj.com/content/352/bmj.i243">Ebola outbreak</a> in West Africa that claimed more than 11,000 lives. And then the 2015-2017 <a href="http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0006007">Zika virus</a> outbreak that closely followed during which 3,500 babies were born with nervous system or eye damage. </p>
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<p>
<em>
<strong>
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>The <a href="http://rstb.royalsocietypublishing.org/content/367/1604/2864">first report</a> of human virus infection was <a href="https://www.wiki.sanitarc.si/1901-walter-reed-proved-finlay-s-theory-yellow-fever-transmitted-aedes-aegypti-mosquito/">yellow fever</a> in the US army at the turn of the 20th century. And now, estimates suggest three to four new species of human viruses are <a href="http://rspb.royalsocietypublishing.org/content/275/1647/2111">found each year</a> and around 250 human virus species are yet to be discovered.</p>
<p>Discovery of a new virus today is complex and requires many steps. Typically, it involves describing its complete genetic code with a combination of intensive molecular sequencing work in the laboratory and computational analyses using enormous reference databases. </p>
<p>Medical epidemiological studies (that look at the distribution of disease) and biological experiments are then needed to understand any virus as a dangerous human pathogen. It may then take some time to link a virus with a particular human disease. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/225269/original/file-20180628-112611-10ee357.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225269/original/file-20180628-112611-10ee357.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/225269/original/file-20180628-112611-10ee357.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225269/original/file-20180628-112611-10ee357.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225269/original/file-20180628-112611-10ee357.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225269/original/file-20180628-112611-10ee357.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225269/original/file-20180628-112611-10ee357.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225269/original/file-20180628-112611-10ee357.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Human parechoviruses were only discovered in the 1950s.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>For instance, <a href="http://www.health.nsw.gov.au/infectious/factsheets/pages/parechovirus.aspx">human parechoviruses</a> (which can cause severe disease in young children) were discovered in the 1950s. But they were <a href="https://www.ncbi.nlm.nih.gov/pubmed/14769896">only identified</a> as a cause of disease in young children in 2004. And relatively <a href="https://wwwnc.cdc.gov/eid/article/21/7/14-1149_article">large Australian epidemics</a> since 2013 have highlighted their link to a serious sepsis-like illness and potential for developmental complications.</p>
<h2>How humans contribute</h2>
<p>Modern humans contribute to the success of dangerous viruses. A virus replicates only when inside the cell of a living being, and spreads most efficiently when there is contact between two individuals. </p>
<p>The United Nations measures current <a href="https://esa.un.org/unpd/wpp/publications/Files/WPP2017_KeyFindings.pdf">world population growth</a> at more than 1% per year. From the virus’ perspective, potential incubators are increasing. The world’s population is also <a href="https://esa.un.org/unpd/wup/publications/Files/WUP2018-KeyFacts.pdf">urbanising</a>, which means people living in closer proximity, which is conducive to spread of a virus. </p>
<p>Domestic and international mass transport permit viruses to move between regional populations.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"997028865934442497"}"></div></p>
<p>Many dangerous virus infections are zoonoses, which are diseases transmitted to humans from other animals. Bats are a common culprit – one theory is that a <a href="https://www.ncbi.nlm.nih.gov/pubmed/29421321">unique low-grade immune system</a> allows them to carry a relatively high number of viruses without developing disease. Epidemics caused by severe acute respiratory syndrome (SARS) coronavirus probably began through bat-human contact. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/why-bats-dont-get-get-sick-from-the-deadly-diseases-they-carry-55012">Why bats don't get get sick from the deadly diseases they carry</a>
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<p>Expanding settlement towards wilderness areas provides more opportunities for viruses to meet people. Domesticated livestock may carry viruses that infect humans, and the growing human population dictates increasing and more compact livestock production. </p>
<p>Influenza virus infects pigs, cattle and poultry as well as humans. The <a href="https://www.cdc.gov/flu/avianflu/h7n9-virus.htm">H7N9 strain</a> that has infected more than 1,500 people in China and resulted in the death of one-third since 2013, first moved to humans from diseased poultry.</p>
<p>When it comes to numbers though, the most <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)61151-9/abstract">important viral transporter</a> is the mosquito. The bite of certain Aedes mosquitoes, for instance, is the primary route for infection with dengue, <a href="https://theconversation.com/explainer-where-did-zika-virus-come-from-and-why-is-it-a-problem-in-brazil-53425">Zika</a> and chikungunya viruses. Queensland is home to these mosquitoes, so outbreaks of dengue <a href="https://www.health.qld.gov.au/__data/assets/pdf_file/0022/444433/dengue-mgt-plan.pdf">occur annually</a>, usually due to an infected traveller arriving from an endemic region. </p>
<p>Research conducted in the Amazon has linked expansion of the mosquito range in endemic areas to <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)61151-9/abstract">deforestation and low re-vegetation</a>. Resistance to the relatively few available insecticides may also contribute to their population growth.</p>
<h2>Why viruses are sneaky</h2>
<p>The basic biology of viruses contributes to their capacity to cause disease. Most human viruses replicate almost instantaneously and in huge numbers. As a result, mutations arise at a high rate in the genetic code of a virus. This allows the virus to adapt quickly to an adverse environment, such as the human immune system or drugs. It may also allow a virus to jump from an animal host to humans.</p>
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<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>
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<p>Some viruses establish a chronic infection, which extends the potential for transmission. After acute illness, Ebola virus hides for many months in parts of the body that generate weak inflammatory responses, such as the <a href="http://www.who.int/reproductivehealth/topics/rtis/ebola-virus-semen/en/">sexual organs</a>, the <a href="https://www.ncbi.nlm.nih.gov/pubmed/28721309">brain and/or the eye</a>.</p>
<p>And although human immunodeficiency virus (HIV) may cause an acute illness, there is usually a long delay between infection and the onset of any disease. Consequently infected people may pass on HIV for years before being aware that they carry the virus.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225271/original/file-20180628-112604-1nqaooe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225271/original/file-20180628-112604-1nqaooe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225271/original/file-20180628-112604-1nqaooe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225271/original/file-20180628-112604-1nqaooe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225271/original/file-20180628-112604-1nqaooe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225271/original/file-20180628-112604-1nqaooe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225271/original/file-20180628-112604-1nqaooe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225271/original/file-20180628-112604-1nqaooe.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">Mosquitoes are responsible for the most viral transmissions.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>There are no specific drugs for most dangerous human viruses. This is in part because viruses are a fast growing and diverse group, with no common drug targets to exploit, as has been possible with antibiotics for bacteria. </p>
<p>But another challenge relates to the viral life cycle, which uses the infected person’s cell machinery. Drugs that target the growth of viruses therefore have effects on the person’s cell, which may result in drug side effects. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/hiv-latency-a-high-stakes-game-of-hide-and-seek-49665">HIV latency: a high-stakes game of hide and seek</a>
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<hr>
<p>Also, the capacity of a virus to adapt implies the potential to develop resistance to a drug. Drug treatment for HIV infection involves a <a href="https://aidsinfo.nih.gov/understanding-hiv-aids/fact-sheets/21/56/drug-resistance#">combination of drugs</a> with different actions to address this problem.</p>
<p>Despite the many challenges associated with dangerous viruses, research continues to yield even more innovative solutions. The <a href="https://www.worldmosquitoprogram.org/">World Mosquito Program</a>, run out of Monash University, is one example. This program is based on the discovery that a safe and natural bacteria, <em>Wolbachia</em>, stops viral growth in the mosquito. Insects in regions endemic with mosquito-borne diseases are being infected with <em>Wolbachia</em> to break the transmission cycle. </p>
<p>Ultimately, the cunning strategies used by dangerous viruses are no match for the wide breadth of human ingenuity.</p><img src="https://counter.theconversation.com/content/94747/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Justine R. Smith receives funding from the National Health & Medical Research Council (NHMRC), the Australian Research Council (ARC) and the Rebecca L. Cooper Medical Research Foundation. She is a Science & Technology Australia Superstar of STEM.</span></em></p><p class="fine-print"><em><span>Jill Carr receives funding from the National Health and Medical Research Council (NHMRC). </span></em></p>It doesn’t just seem like the world is experiencing more viral infections than before – it’s a reality. And the way humans live today helps viruses thrive.Justine R. Smith, Professor of Eye & Vision Health, Flinders UniversityJill Carr, Associate Professor, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/966882018-05-21T10:45:25Z2018-05-21T10:45:25ZTicks and mosquitoes bringing more diseases – what can we do?<figure><img src="https://images.theconversation.com/files/219593/original/file-20180518-42220-1w0agca.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A female deer tick on a piece of straw. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/close-photo-adult-female-deer-tick-342282746?src=G3L6_jMyg7rlKsjzxdYGuQ-1-44">Steve Ellingson/Shutterstock.com</a></span></figcaption></figure><p>Cases of <a href="https://www.cdc.gov/ncezid/dvbd/index.html">vector-borne disease</a> have <a href="https://www.cdc.gov/mmwr/volumes/67/wr/mm6717e1.htm?s_cid=mm6717e1_w">more than doubled</a> in the U.S. since 2004, the Centers for Disease Control and Prevention recently reported, with mosquitoes and ticks bearing most of the blame.</p>
<p>Mosquitoes, long spreaders of malaria and yellow fever, have more recently spread dengue, Zika and Chikungunya viruses, and caused epidemic outbreaks, <a href="https://www.cdc.gov/zika/geo/index.html">mainly in U.S. territories</a>. The insects are also largely responsible for making <a href="https://www.cdc.gov/westnile/index.html">West Nile virus</a> endemic in the continental U.S. </p>
<p>Ticks, which are not insects but <a href="http://ento.psu.edu/extension/factsheets/ticks">parasitic arthropods</a>, actually cause more disease in the U.S. than mosquitoes do, accounting for <a href="https://www.cdc.gov/mmwr/volumes/67/wr/mm6717e1.htm?s_cid=mm6717e1_w">76.51 percent of total U.S. vector-borne disease cases</a>. These include Lyme disease and Rocky Mountain spotted fever and newer diseases as well. </p>
<p>Why the uptick in vector-borne disease, and more importantly, how can we protect ourselves from potentially serious diseases? As researchers of these types of diseases, we have some answers. </p>
<h2>Blood: The high cost of living</h2>
<p>Both mosquitoes and ticks transmit disease-causing pathogens through bites.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/219261/original/file-20180516-155579-es58gg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/219261/original/file-20180516-155579-es58gg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/219261/original/file-20180516-155579-es58gg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/219261/original/file-20180516-155579-es58gg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/219261/original/file-20180516-155579-es58gg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/219261/original/file-20180516-155579-es58gg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/219261/original/file-20180516-155579-es58gg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Shelley Whitehead</span></span>
</figcaption>
</figure>
<p>Only the female mosquito takes a blood meal to make eggs, but almost all life stages of ticks need blood to survive.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/219264/original/file-20180516-155584-1b2e2gz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/219264/original/file-20180516-155584-1b2e2gz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/219264/original/file-20180516-155584-1b2e2gz.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/219264/original/file-20180516-155584-1b2e2gz.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/219264/original/file-20180516-155584-1b2e2gz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/219264/original/file-20180516-155584-1b2e2gz.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/219264/original/file-20180516-155584-1b2e2gz.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"></span>
<span class="attribution"><span class="source">Joyce Sakamoto</span></span>
</figcaption>
</figure>
<p>Although mosquitoes were first demonstrated to have the ability to transmit diseases <a href="https://wwwnc.cdc.gov/eid/article/24/5/pdfs/17-1609.pdf">in 1889</a>, mosquitoes have been transmitting diseases for far longer. Written records as early as 2700 B.C. suggest <a href="https://parasitesandvectors.biomedcentral.com/track/pdf/10.1186/1756-3305-3-5">malaria plagued humans in China</a>.</p>
<p>The first suspected dengue outbreak occurred in the early 1600s, but it took three centuries for the first three mosquito-borne diseases – malaria, dengue and yellow fever – to invade the Americas. Yet, in the past two decades alone, we’ve experienced a wave of <a href="https://www.cdc.gov/zika/reporting/case-counts.html">three more mosquito-borne diseases</a> – <a href="https://link.springer.com/content/pdf/10.1007%2Fs40475-013-0008-1.pdf">West Nile, Chikungunya and Zika viruses</a>. This marked increase in disease spread is due to several factors, including advances in air and water travel and <a href="https://theconversation.com/global-warming-to-expose-more-people-to-zika-spreading-mosquito-aedes-aegypti-58908">warming temperatures</a>. </p>
<h2>The high cost of international travel and trade</h2>
<p>The international tire trade has made <em>Aedes albopictus</em>, the Asian tiger mosquito, a global traveler. This mosquito gains passage on <a href="https://www.npr.org/programs/atc/features/2001/mar/010309.disease.html">cargo ships</a> and gets unlimited access to man-made containers, which it needs for breeding, in the thousands of tires on board these ships. Rainwater collecting in the tires are ideal breeding sites. Even though it is not a major vector of dengue, Chikungunya and Zika viruses, this invasive species is still especially dangerous. It is able to outcompete most other mosquito species that live in similar habitats. </p>
<p>We humans serve as hosts for many vector-borne diseases, and our own movement can aid transmission. We can hop on a plane and be in a different country within hours. Diseases once quarantined to other regions of the globe can now be easily transported within an infected human. Some people don’t even realize they are sick. Researchers have estimated that up to 80 percent of individuals infected with Zika virus are <a href="https://www.nature.com/articles/s41598-017-05013-9.pdf">symptomless</a>. Yet, if the right vector feeds on a symptomless but infected person, transmission can still occur. </p>
<p>Increased <a href="https://academic.oup.com/femsle/article/364/19/fnx186/4107775">climate fluctuations</a>, largely due to human activity, can also affect how vector-borne diseases spread. Warmer climates may allow mosquitoes to survive in areas previously too cold to support them.</p>
<p>Predicting the outcome of warming on overall vector populations can be difficult. If, for example, summer in the deep Southeast becomes too hot and dry for mosquito development, peaks in transmission and mosquito numbers could shift to the fall. Higher temperatures may shorten the time it takes for pathogens to develop within mosquitoes, so mosquitoes may become <a href="http://www.pnas.org/content/pnas/106/33/13844.full.pdf">infectious faster</a> and transmit pathogens sooner. </p>
<h2>Tick-borne diseases</h2>
<p><a href="https://www.cell.com/trends/parasitology/fulltext/S1471-4922(12)00121-3?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1471492212001213%3Fshowall%3Dtrue">Five percent of 900 tick species</a> are known to transmit disease-causing microorganisms. Because <a href="https://doi.org/10.1007/978-94-007-7497-1">38 percent of all tick species</a> have been known to bite humans, researchers will likely find more tick-borne diseases. Since 2004, there have been nine new vector-borne diseases described in the U.S., and seven of these are tick-transmitted, including the two potentially fatal Bourbon and Heartland viruses. </p>
<p>Most, or <a href="https://www.cdc.gov/mmwr/volumes/67/wr/mm6717e1.htm?s_cid=mm6717e1_w">82 percent</a> of tick-borne disease cases, are Lyme disease, which is caused by the bacteria <em>Borrelia burgdorferi</em>, and transmitted by the blacklegged, or deer, tick. <a href="https://doi.org/10.15585/mmwr.mm6717e1">Cases</a> of Lyme, Rocky Mountain spotted fever, babesiosis, anaplasmosis and ehrlichiosis have increased two-and-a-half to six-and-a-half fold.</p>
<p>Tick-borne diseases may be rising due to global travel, animal transport, habitat fragmentation and changing climate. <a href="https://doi.org/10.3390/ijerph15030478">Climate change</a> is correlated with range expansion of several important tick species. Ticks previously limited by cold winters are now becoming established farther north. In response to the arrival of Lyme disease to Canadian soil, the Public Health Agency of Canada responded with a <a href="https://www.canada.ca/en/public-health/services/publications/diseases-conditions/lyme-disease-canada-federal-framework.html">Federal Framework on Lyme Disease</a> focused on disease surveillance, education and awareness, and best practices for control, prevention and treatment of Lyme disease.</p>
<h2>What can you do?</h2>
<p>To lower your risk of transmission from mosquitoes: </p>
<ul>
<li><p>Check backyards for anything that could hold water and empty such vessels. This includes children’s toys, bird baths, empty soda cans and flower pots.</p></li>
<li><p>Use mosquito repellents that are <a href="https://www.epa.gov/insect-repellents">EPA</a> approved. Avoid natural repellents that haven’t been verified for their effectiveness. </p></li>
</ul>
<p>To prevent tick bites: </p>
<p>One sure way to prevent tick bites is to avoid suitable habitats for ticks, but this isn’t always possible. Large-scale habitat control or acaricide (tick-killing) treatment of wildlife, though possible, can be difficult or not cost-effective for homeowners. The best preventative measures are:</p>
<ul>
<li><p>Use CDC-recommended repellents such as DEET or picaridin. </p></li>
<li><p>Shower and do a thorough tick check.</p></li>
</ul>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/219319/original/file-20180517-155573-f3ou6q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/219319/original/file-20180517-155573-f3ou6q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/219319/original/file-20180517-155573-f3ou6q.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/219319/original/file-20180517-155573-f3ou6q.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/219319/original/file-20180517-155573-f3ou6q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/219319/original/file-20180517-155573-f3ou6q.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/219319/original/file-20180517-155573-f3ou6q.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">Tick check.</span>
<span class="attribution"><span class="source">Joyce Sakamoto</span></span>
</figcaption>
</figure>
<p>Tick checks are absolutely crucial. People usually follow this routine after going outdoors, but sometimes forget. And, they often avoid places that ticks love, such as between your legs. Hard-to-reach areas are prime real estate for blood-feeding parasites that don’t want to be dislodged, so make sure to check: the hairline (especially on children), torso, belly button and groin. If necessary, get assistance or a mirror and a bright light. </p>
<p>If you find an embedded tick, <a href="https://www.cdc.gov/ticks/removing_a_tick.html">correctly dislodge it</a> with fine-tipped tweezers, grasping the part closest to the skin and pulling straight up. Do not burn, squeeze, twist or smother the tick, since this may cause it to regurgitate. Gross-out alert: Any pathogens they have in their saliva can then be dumped into the bite site. </p>
<p>After removal, keep the tick for identification; different species transmit different pathogens. Finally, see a doctor after finding an embedded tick or if you think you have been bitten. In addition to getting medical attention, your data will be added to the national list of reported tick-borne diseases. </p>
<p>The CDC has several pages dedicated to vector-borne disease control and prevention. Local state health departments, general practitioners and veterinarians will also have recommendations for prevention, treatment and vector control. Talk to your veterinarian about repellents or agents that will kill mites called <a href="https://www.medicinenet.com/script/main/art.asp?articlekey=25533">acaricides</a> for pets, since some can be toxic to cats.</p><img src="https://counter.theconversation.com/content/96688/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Joyce Sakamoto receives funding from NSF. </span></em></p><p class="fine-print"><em><span>Shelley Whitehead receives funding from NIH NIAID. </span></em></p>The CDC recently announced an uptick in diseases spread by vectors such as mosquitoes and ticks. Here’s why and what you can do to lower your risk.Joyce Sakamoto, Assistant Research Professor of Entomology, Penn StateShelley Whitehead, Doctoral Candidate, Entomology, Penn StateLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/802692017-07-16T19:56:40Z2017-07-16T19:56:40ZMozzies are evolving to beat insecticides – except in Australia<figure><img src="https://images.theconversation.com/files/178024/original/file-20170713-9462-16t5ncj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mosquitoes are the main vectors for dengue and zika. Insecticides are our best weapon against them. </span> <span class="attribution"><span class="source">Anja Jonsson/Flickr</span></span></figcaption></figure><p>Chemical pesticides have been used for many years to control insect populations and remain the most important method of managing diseases carried by pests, including mosquitoes. However, insects have fought back by evolving resistance to many pesticides. <a href="https://www.pesticideresistance.org/">There are now thousands of instances of evolved resistance</a>, which make some chemical classes completely ineffective.</p>
<p>The <em>Aedes</em> mosquito, largely responsible for the spread of viruses like dengue and zika, has globally developed <a href="http://unifeb.edu.br/uploads/arquivos/revista-cientifica/Toxicidade_aguda_de_inseticidas_e_espalhante_usados_no_controle_de_vetores.pdf">resistance to commonly used chemicals, including pyrethroids</a>. Pyrethroids are the most used insecticides in the world, which includes the control of dengue outbreaks and quarantine breaches at air and sea ports.</p>
<p>In Asia and the Americas, pyrethroid resistance in <em>Aedes</em> mosquitoes is now <a href="http://journal.tropika.net/scielo.php?script=sci_arttext&pid=s2078-86062010000100003&lng=en">widespread</a>. In Australia, our mosquitoes have not developed these defences and pyrethroids are still very effective.</p>
<p>The difference lies in our stringent and careful protocols for chemical use. As the global community fights zika and other mosquito-borne diseases, there are lessons to be learned from Australia’s success. </p>
<h2>Developing resistance</h2>
<p>Mosquitoes usually become resistant to pyrethroids through the <a href="http://www.mdpi.com/2075-4450/7/4/60">mutation of a sodium channel gene</a> that controls the movement of ions across cell membranes. Mutations in a single gene are enough to make mosquitoes almost completely resistant to the level of pyrethroids used in insecticides. </p>
<p>The mutations first arises in a population by chance, and are rare. However, they rapidly spread as resistant females breed. The more times a mosquito population is exposed to the same chemical, the more the natural selection process favours their impervious offspring.</p>
<p>Eventually, when many individuals in a population carry the resistance mutation, the chemical becomes ineffective. This can <a href="https://www.mosquitonets.com/blog/the-practice-of-fogging/">happen where insecticide “fogging” is common practice</a>. Overseas, fogging is sometimes undertaken across entire neighbourhoods, several times a month, <a href="http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0004551">despite concerns about its effectiveness</a> as well as <a href="http://www.todayonline.com/voices/widespread-fogging-may-do-more-harm-good">its environmental and health impacts</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/178025/original/file-20170713-10278-1tiyfhp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178025/original/file-20170713-10278-1tiyfhp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=389&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178025/original/file-20170713-10278-1tiyfhp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=389&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178025/original/file-20170713-10278-1tiyfhp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=389&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178025/original/file-20170713-10278-1tiyfhp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=489&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178025/original/file-20170713-10278-1tiyfhp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=489&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178025/original/file-20170713-10278-1tiyfhp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=489&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A pest exterminator carries out insecticide fogging in an apartment block in Singapore.</span>
<span class="attribution"><a class="source" href="http://one.aap.com.au/#/search/mosquitoes?q=%7B%22pageSize%22:25,%22pageNumber%22:2%7D">EPA, Wallace Woon/AAP</a></span>
</figcaption>
</figure>
<p>Once resistance develops, it can spread to non-resistant mosquito populations in other areas. Pest species, including mosquitoes, are often highly mobile because they fly or are carried passively (in vehicles, ships and planes) at any stage of their life cycle. Their mobility means mutations spread quickly, crossing borders and possibly seas. </p>
<h2>We can still control Australian mosquitoes</h2>
<p>Despite this, Australian populations of <em>Aedes</em> mosquitoes remain susceptible to pyrethroids. <em>Aedes aegypti</em> (the yellow fever mosquito) is the main disease-carrying mosquito in Australia. Its population is restricted to urban areas of northern Queensland, where dengue can occur. </p>
<p>Recent research found that <a href="https://academic.oup.com/jme/article-abstract/doi/10.1093/jme/tjx145/3964514/Pyrethroid-Susceptibility-Has-Been-Maintained-in?redirectedFrom=fulltext">all Australian populations of this species are still vulnerable to pyrethroids</a>. None of the hundreds of mosquitoes tested had any mutations in the sodium channel gene, despite the high incidence of such mutations in <a href="https://www.ncbi.nlm.nih.gov/pubmed/26463408">mosquito populations of South-East Asia</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/178027/original/file-20170713-19645-sqvtig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178027/original/file-20170713-19645-sqvtig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178027/original/file-20170713-19645-sqvtig.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178027/original/file-20170713-19645-sqvtig.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178027/original/file-20170713-19645-sqvtig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=507&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178027/original/file-20170713-19645-sqvtig.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=507&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178027/original/file-20170713-19645-sqvtig.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=507&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A female <em>Aedes aegypti</em> mosquito during a feed.</span>
<span class="attribution"><a class="source" href="https://phil.cdc.gov/phil/details.asp?pid=9178">James Gathany, CDC Prof Frank Hadley Collins/Wikimedia</a></span>
</figcaption>
</figure>
<p>We believe these mosquitoes remain vulnerable to pyrethroids because in Australia pressure to select for resistance has been low. </p>
<p>Australia does not carry out routine fogging. If <a href="https://www.health.qld.gov.au/__data/assets/pdf_file/0022/444433/dengue-mgt-plan.pdf">dengue is detected in an area</a>, pyrethoids are used in highly regimented and limited fashion. Spraying is restricted to the insides of premises within selected house blocks, and then only for a short period. </p>
<p>Importantly, water-filled artificial containers, which can serve as a habitat for larvae, are treated with insect growth regulators, which do not select for the pyrethroid resistance mutations. </p>
<h2>Exporting resistance</h2>
<p>With chemical resistance growing around the world, it is more urgent than ever that we co-ordinate action to control and reduce risk of resistance. Unfortunately, no global guidelines exist to minimise the evolution of resistance in mosquitoes. </p>
<p>Adopting <a href="http://www.irac-online.org/about/resistance/management/">pesticide resistance management strategies</a> has proven to be effective against other pests – for example, the <a href="https://www.daf.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/integrated-pest-management/a-z-insect-pest-list/helicoverpa/insecticide-resistance">corn earworm</a> (<em>Helicoverpa armigera</em>). Guidelines include rotating different class of pesticides to deny pests the chance to develop resistance, and investing in non-chemical options such as natural predators of target pests.</p>
<p>Resistance management strategies are particularly critical for new pesticides that have different <a href="http://www.irac-online.org/modes-of-action/">modes of attack</a>, such as preventing juvenile insects from moulting, or attacking various chemical receptors. </p>
<p>To prolong the effectiveness of pesticides, we must develop these strategies before resistance begins to develop. North Queensland may be an example to the rest of the world on the best path forward.</p><img src="https://counter.theconversation.com/content/80269/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ary Hoffmann receives funding from the National Health and Medical Research Council, the Australian Research Council,
the Wellcome Trust, and the Grains Research and Development Corporation. </span></em></p><p class="fine-print"><em><span>Nancy Margaret Endersby-Harshman receives funding from the National Health and Medical Research Council. </span></em></p><p class="fine-print"><em><span>Scott Ritchie receives funding from the National Health and Medical Research Council, US Dept. of Defence, and USAid.</span></em></p>Australian mosquitoes, unlike their Asian and American counterparts, can still be controlled by insecticides like pyrethroids. What lessons are there for managing pesticide resistance in insects?Ary Hoffmann, Professor, School of BioSciences and Bio21 Institute, The University of MelbourneNancy Margaret Endersby-Harshman, Research fellow, The University of MelbourneScott Ritchie, Professorial Research Fellow, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/789462017-06-11T08:39:31Z2017-06-11T08:39:31ZWith an African running the WHO, it’s time for the continent to get hands on<figure><img src="https://images.theconversation.com/files/172901/original/file-20170608-32301-1fwbyg0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Africa is home to many disease outbreaks yet is ill-prepared to deal with them. </span> <span class="attribution"><span class="source">UNMEER/Martine Perret</span></span></figcaption></figure><p>New World Health Organisation (WHO) <a href="https://theconversation.com/the-whos-new-african-leader-could-be-a-shot-in-the-arm-for-poorer-countries-78277">Director-General</a> Dr Tedros Ghebreyesus has already drawn up a list of <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)31847-5/fulltext">things to do</a>. </p>
<p>The former Ethiopian Health Minister wants the organisation to work with governments to build their national capacity for universal health coverage through strong and resilient health systems. Secondly, he wants to strengthen the WHO’s response to threats such as disease outbreaks. And finally he wants to see the WHO harmonise emergency responses across partners while bolstering frontline defences at national and local levels.</p>
<p>The priorities make sense because the African continent is notorious for being ill-prepared to deal with disease outbreaks, yet it’s home to many emerging and re-emerging diseases such as Ebola, Yellow Fever, meningitis and Lassa Fever. </p>
<p>African leaders have a role to play in helping the new Director-General achieve these objectives. And the best way for them to contribute is by dusting off the 2001 <a href="http://www.who.int/healthsystems/publications/abuja_declaration/en/">Abuja Declaration</a> in which AU member states resolved to increase their health budgets to at least 15% of the state’s annual budget.</p>
<p>Over the last 16 years governments have indeed improved their spending on health. For example, Rwanda currently spends <a href="http://www.africanstrategies4health.org/resources/health-care-financing">22.3%</a> and Togo <a href="http://www.africanstrategies4health.org/resources/health-care-financing">15.4%</a> of their annual budgets on health. Nigeria spends<a href="http://www.africanstrategies4health.org/resources/health-care-financing"> 6.7%</a> and Uganda <a href="http://www.africanstrategies4health.org/resources/health-care-financing">10.2%</a>. South Africa’s <a href="https://www.healthpolicyproject.com/pubs/7887/SouthAfrica_HFP.pdf">health expenditure</a> is 14% of its general expenditure. </p>
<p>But most countries still have a long way to go to ensure that allocations to health are consistent and that the money is spent in ways that bolster the chances of Ghebreyesus meeting the objectives he’s mapped out for the WHO. </p>
<h2>No clear consensus</h2>
<p>Countries signed the declaration because they believed that special efforts and increased funding were needed to prevent and control epidemics and improve the general health of its citizens. But 16 years later there’s still no clarity on who has fulfilled the 15% pledge. Different assessments have come up with different results.</p>
<p>For example, in 2010 the African Union Commission tallied each country’s progress, finding that only <a href="http://www.ppdafrica.org/docs/policy/abuja-e.pdf">six of the 55 member states</a> had met the 15% benchmark. These were Botswana, Burkina Faso, Malawi, Niger, Rwanda and Zambia.</p>
<p>But a more comprehensive <a href="http://www.who.int/healthsystems/publications/Abuja10.pdf">report</a> by the WHO in the same year found that only one African country – Tanzania – had reached the target although 26 had increased their spending on health. The report also showed that 11 countries had actually reduced spending on health and nine had neither a noticeable negative or positive trend. </p>
<p>In another report in 2011, <a href="http://www.unaids.org/sites/default/files/media_asset/JC2524_Abuja_report_en_0.pdf">UNAIDS</a> put the number of African countries who had met the target at nine: Ethiopia, Lesotho, Liberia, Madagascar, Malawi, Rwanda, Swaziland and Togo.</p>
<p>What seems to be generally accepted – and confirmed by the <a href="http://apps.who.int/iris/bitstream/10665/249527/1/WHO-HIS-HGF-Tech.Report-16.2-eng.pdf?ua=1">WHO’s 2016 assessment</a> – is that since the turn of the century most African governments have increased the proportion of total public expenditure allocated to health. </p>
<p>The average level of per capita public spending on health nearly doubled from about <a href="http://data.worldbank.org/indicator/SH.XPD.PCAP">US$70 in the early 2000s</a> to more than <a href="http://apps.who.int/iris/bitstream/10665/249527/1/WHO-HIS-HGF-Tech.Report-16.2-eng.pdf">US$160 in 2014</a> </p>
<p>There’s no clear agreement on what the per capita spend should be. Between 1995 and 2014, the per capita expenditure on health across the world rose from<a href="http://data.worldbank.org/indicator/SH.XPD.PCAP"> US$461 to US$1060</a>. Countries in the European Union spend up to US$3612 per capita while North America spends US$ 8990. </p>
<h2>Challenges ahead</h2>
<p>Health financing faces several challenges which can reverse gains made on the continent over the last 16 years. These include governments deciding to reduce spending on health, the wrong allocation of funds, unpredictable and the inconsistent funding as well as bad financial management. </p>
<p>Research shows that out of every US$100 that governments’ budget, only US$16 is allocated to health. And less than US$4 goes to the<a href="http://apps.who.int/iris/bitstream/10665/249527/1/WHO-HIS-HGF-Tech.Report-16.2-eng.pdf?ua=1"> correct health services</a>. </p>
<p>In many instances, there are weak links between health and public financial management. This leads to under spending, which is a serious impediment for health care workers to access the allocated funds.</p>
<p>These challenges have several knock-on effects. They compromise government’s capacity to sustain long-term progress, they hamper effective planning and undermine efforts to provide the same service throughout a country.</p>
<p>The reality is that each African country must provide adequate domestic resources to create environments where health workers can get the job done. This would need leaders on the continent to use these resources in an accountable and transparent way with less dependence on external aid and global support. </p>
<p>This is because donor funding presents its own set of challenges. External aid makes up <a href="http://apps.who.int/iris/bitstream/10665/249527/1/WHO-HIS-HGF-Tech.Report-16.2-eng.pdf">24% of the health spend </a>of governments on the continent. But funding can be unpredictable and subject to the interest of the donor which may not tally with pressing health problems faced by countries. On top of this donor funds can get sucked into the vortex of corruption and misapplication of domestic funds unless there are proper frameworks for accountability and transparency. </p>
<p>The bottom line is that extra spending by African governments needs to be channelled to the three areas outlined by the Director-General. Without this, his ambitious plans for improving health care on the continent won’t be realised.</p><img src="https://counter.theconversation.com/content/78946/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Oyewale Tomori 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>African leaders need to up their health allocations to help the new World Health Organisation Director-General meet his health care targets for the continent.Oyewale Tomori, Fellow, Nigerian Academy of ScienceLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/680252016-11-02T09:17:15Z2016-11-02T09:17:15ZScientists turn one pathogen against another in fight against dengue and Zika<figure><img src="https://images.theconversation.com/files/144110/original/image-20161101-11456-2s4w5m.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://commons.wikimedia.org/wiki/File:Aedes_aegypti.jpg">Muhammad Mahdi Karim</a></span></figcaption></figure><p>Mosquitoes have been described as the most dangerous animals in the world due to their role in spreading diseases such as <a href="http://www.who.int/features/factfiles/malaria/en/">malaria</a>, <a href="http://www.who.int/mediacentre/factsheets/fs117/en/">dengue</a>, <a href="http://www.who.int/mediacentre/factsheets/fs327/en/">chikugunya</a> and <a href="http://www.who.int/mediacentre/factsheets/fs100/en/">yellow fever</a>. Hundreds of millions of people are infected every year, leading to <a href="http://www.who.int/features/factfiles/malaria/en/">many hundreds of thousands of deaths</a>.</p>
<p>One of the biggest concerns this year has been the rapid spread of <a href="http://www.who.int/mediacentre/factsheets/zika/en/">Zika</a>, another virus in the same family as dengue and the yellow fever viruses. There is no vaccine available that is able to protect people from Zika infection at present, and no known cure. So the challenge is to prevent the means of infection: the bite of the mosquito, <em>Aedes aegypti</em>.</p>
<p>Unlike other species of mosquito that transmit the malaria parasite, <em>Aedes</em> mosquitoes bite during the day, which means sleeping under a net offers little protection. Insecticides have been effective but resistance develops rapidly, and public health programmes that target and remove mosquito breeding sites are expected to be difficult to sustain. This has led to a sophisticated new approach that uses one species of parasite to prevent the spread of another.</p>
<h2>Bacteria vs virus</h2>
<p>The parasites in question belong to a group of bacteria called <a href="http://www.eliminatedengue.com/our-research/wolbachia">Wolbachia</a>. These naturally infect a great number of insect species, in which they inhabit tissues including the insect’s ovaries. From here they infect the developing eggs, and so are passed on to the next generation. Although it’s only female insects that can pass the bacteria on to their offspring, the bacteria can reduce the reproductive capability of both male and female hosts. Depending upon the species of Wolbachia, this can lead to sterility, or to swing the sex ratio of offspring in favour of females – which in turn means Wolbachia will spread more rapidly through the insect population through successive generations of infected eggs.</p>
<p>However, Wolbachia infection is not all bad news for insects: there is evidence that Wolbachia also prevents other pathogens from developing in host insects. </p>
<p>For several years, an Australian research group led by <a href="https://www.monash.edu/science/schools/biological-sciences/staff2/oneill">Scott O’Neill</a> has taken advantage of this as a strategy to control the spread of dengue viruses. But in order to use Wolbachia to prevent other pathogens from infecting <em>Aedes</em> mosquitoes, first they had to overcome a big hurdle because <em>Aedes</em> are not naturally infected with Wolbachia. </p>
<p>Using very fine needles, they were able to inject Wolbachia from other insects into newly laid <em>Aedes</em> eggs. The bacteria survived inside the mosquitoes that hatched from the eggs, and began to spread naturally through further generations of their lab mosquito colony. When those mosquitoes infected with Wolbachia were subsequently infected with dengue, the dengue virus was not able to replicate and spread to the mosquito’s salivary glands – and so the mosquitoes could not transmit dengue.</p>
<p><a href="http://www.cell.com/cell/abstract/S0092-8674(09)01500-1?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867409015001%3Fshowall%3Dtrue">Subsequent research</a> has demonstrated that the same technique using Wolbachia also reduces the ability of <em>Aedes</em> mosquitoes to transmit the viruses that cause yellow fever, chikungunya and Zika – and there is some evidence that it can inhibit transmission of the malaria parasite in other mosquito species. The mechanism by which Wolbachia infection does this is not clear, but it’s likely that it involves a change to the mosquito’s immune system.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/144107/original/image-20161101-15814-3cic7w.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/144107/original/image-20161101-15814-3cic7w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/144107/original/image-20161101-15814-3cic7w.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=246&fit=crop&dpr=1 600w, https://images.theconversation.com/files/144107/original/image-20161101-15814-3cic7w.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=246&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/144107/original/image-20161101-15814-3cic7w.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=246&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/144107/original/image-20161101-15814-3cic7w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=309&fit=crop&dpr=1 754w, https://images.theconversation.com/files/144107/original/image-20161101-15814-3cic7w.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=309&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/144107/original/image-20161101-15814-3cic7w.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=309&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Map showing the global distribution of the <em>Aedes aegypti</em> mosquito which spreads dengue and other diseases.</span>
<span class="attribution"><a class="source" href="https://elifesciences.org/content/4/e08347">Moritz UG Kraemer/eLife</a></span>
</figcaption>
</figure>
<h2>Weaponising mosquitoes</h2>
<p>Unlike the viruses, Wolbachia bacteria are too big to pass through the mosquito’s salivary duct when she bites a human, so there’s no chance that Wolbachia-infected mosquitoes can spread Wolbachia to humans – indeed, Wolbachia is not dangerous to humans. Stringent independent risk assessments have concluded that these mosquitoes were of negligible risk to humans or the environment, so trial releases of these mosquitoes have now taken place in Australia. By breeding with wild <em>Aedes</em>, the infected mosquitoes have rapidly spread Wolbachia throughout the population. The <a href="http://www.eliminatedengue.com/program">Eliminate Dengue</a> project has now also released mosquitoes in Indonesia, Vietnam, Colombia and Brazil.</p>
<p>In Brazil, <a href="http://www.eliminatedengue.com/progress/index/article/739">the positive results</a> from two pilot releases of Wolbachia-carrying mosquitoes have led to plans to expand the programme across the Rio de Janeiro and Niterói regions and monitor the effects on mosquito-borne viral infections. Facilities there are capable of producing 10m Wolbachia-infected <em>Aedes</em> eggs for release every week.</p>
<p>In the US, the <a href="http://mosquitomate.com/science-research/">Mosquito Mate</a> project is using a similar technique but instead aims to reduce the number of biting mosquitoes in an area rather than preventing the spread of disease. Using a different species of Wolbachia that causes sterility in the Asian tiger mosquito (<em>Aedes albopictus</em>), the project has released Wolbachia-carrying male mosquitoes which mate with wild females. As no fertile eggs result, the mosquito population declines. However, unlike the Eliminate Dengue strategy, this approach requires continual releases of mosquitoes because this strain of Wolbachia cannot spread naturally within the mosquito population. </p>
<p>Because Wolbachia-carrying mosquitoes are regarded as biopesticides, Mosquito Mate quickly got regulatory approval by the US Environmental Protection Agency. This is in contrast to the experience of firms such as <a href="http://www.oxitec.com/">Oxitec</a> which use genetically modified male mosquitoes that are sterile.</p>
<p>It may take several years to determine whether either of these strategies actually reduces or even eliminates the spread of mosquito-borne viral diseases – but if successful the implications for the millions affected by these diseases worldwide are enormous.</p><img src="https://counter.theconversation.com/content/68025/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hilary Hurd 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>There’s a new weapon against mosquitoes that spreads diseases such as dengue and yellow fever – more mosquitoes.Hilary Hurd, Emeritus Professor of Parasitology, Keele UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/674472016-10-27T00:51:27Z2016-10-27T00:51:27ZPitting mozzies against mozzies to stop the spread of disease<figure><img src="https://images.theconversation.com/files/142973/original/image-20161024-28420-1o2tc0l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cages full of hand reared yellow fever mosquitoes await research (or possibly release)</span> <span class="attribution"><span class="source">Cameron Webb, NSW Health Pathology/University of Sydney</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Mosquitoes and the burden of disease they cause continue to weigh down many communities around the world. Despite their fragile appearance, mosquitoes continue to resist our best efforts to eliminate them. We’ve drained and polluted their wetland homes, and we’ve filled the skies with clouds of insecticides, but still they persist.</p>
<p>There is no reason why mosquito-borne disease won’t continue to spread in the decades ahead. While <a href="https://theconversation.com/is-climate-change-to-blame-for-outbreaks-of-mosquito-borne-disease-39176">climate change, urbanisation and globalisation</a> will all influence future mosquito-borne disease risks, some of our current control products are also losing their potency.</p>
<p>In many ways, our efforts to control mosquitoes have also been our undoing. We constantly underestimate the resilience of mosquitoes. The more insecticides we use to try and kill mosquitoes, the greater the likelihood they will <a href="http://onlinelibrary.wiley.com/doi/10.1111/aen.12186/full">develop resistance to these chemicals</a>. We need to look at alternative ways to control mosquitoes, and a new project pitting mosquitoes against mosquitoes is being trialled in Australia.</p>
<h2>Bugging the mosquito</h2>
<p>While there are thousands of mosquito species worldwide (<a href="http://www.publish.csiro.au/book/6391/">over 300 in Australia alone</a>), the yellow fever mosquito (<em>Aedes aegypti</em>) is of greatest concern when it comes to outbreaks of dengue, chikungunya and Zika viruses. Second on the list is the Asian tiger mosquito (<em>Aedes albopictus</em>), a severe pest that also transmits these viruses. These <a href="https://theconversation.com/new-mosquito-threats-shift-risks-from-our-swamps-to-our-suburbs-56350">two exotic mosquitoes</a> have proven great at invading the world, spreading outwards to live with us in our cities. And they do love biting people.</p>
<p>It is important to remember that only female mosquitoes bite in pursuit of blood. Male mosquitoes do not, feeding only on nectar.</p>
<p>New approaches using an insect-specific bacteria have been developed that can sabotage mosquito populations. This works by either disrupting their reproduction or blocking their ability to transmit pathogens.</p>
<p>Scientists have concentrated their research on a naturally occurring insect bacteria, <a href="http://onlinelibrary.wiley.com/doi/10.1111/aen.12068/full"><em>Wolbachia</em></a>.</p>
<p><em>Wolbachia</em> doesn’t naturally infect all mosquitoes. However, studies have shown female mosquitoes infected in a laboratory with <em>Wolbachia</em> pass the infection through to their eggs. Then when males infected with the bacteria mate with uninfected females, the female’s eggs do not hatch. The reasons for this <a href="https://www.scientificamerican.com/article/fighting-mosquitoes-with-mosquitoes/">are not yet fully understood</a> but is known as “cytoplasmic incompatibility”.</p>
<p>Male <em>Wolbachia</em>-infected mosquitoes reared in the laboratory can be released into the field. As females only mate once, each successful mating results in no eggs hatching in the next generation. Therefore, the mosquito population shrinks over time. </p>
<p>Given these frisky male mosquitoes are better at finding female mosquitoes than we are with our insecticides, this approach could be a winner. It avoids increasing the risks of insecticide resistance and reduces the risks of other species in the area being <a href="https://entomologytoday.org/2015/03/23/wolbachia-bacteria-can-control-mosquitoes-with-fewer-chemicals/">impacted by insecticides</a>.</p>
<h2>How would this beat disease?</h2>
<p>Trials that use males carrying this bacteria to suppress mosquito populations of the Asian tiger mosquito are now occurring in the <a href="http://www.nature.com/news/us-reviews-plan-to-infect-mosquitoes-with-bacteria-to-stop-disease-1.19967">USA</a> and <a href="https://www.theguardian.com/world/2015/may/24/sterile-mosquitoes-released-in-china-to-fight-dengue-fever">China</a>. Singapore recently began its first trials <a href="http://www.nea.gov.sg/public-health/environmental-public-health-research/wolbachia-technology/project-wolbachia-singapore">releasing bacteria-infected male yellow fever mosquitoes</a> throughout their high-rise apartments in an effort to study and remove mosquito populations that have proven tricky to control.</p>
<p>The <a href="http://www.eliminatedengue.com/program">Eliminate Dengue</a> group from Monash University is also using this type of bacteria for population replacement of the yellow fever mosquito. In their novel approach, once the bacteria is established in the population of mosquitoes, dengue, Zika and chikungunya viruses cannot infect the mosquito, making the insect population resistant to transmission. Releases of these mosquitoes have been underway in northern Australia for more than five years, and the <a href="http://www.abc.net.au/news/2016-10-27/zika-eliminate-dengue-project-to-expand-after-qld-success/7969038">results are very promising</a>. There are plans to expand the approach to <a href="https://www.theguardian.com/world/2016/oct/26/mosquitos-infected-wolbachia-bacteria-zika-virus">South America</a>. </p>
<h2>Where to from here?</h2>
<p>These new ways forward seem to offer a choice between using this common bacteria for either population suppression or replacement. The great benefit is that all these approaches use mosquitoes against mosquitoes.</p>
<p>While early successes of laboratory and field trials are already coming in, these small-scale and well-funded research projects may not reflect the reality of what is required in the long-term. How can we “scale up” these approaches to deploy them across the many major urban centres suffering from outbreaks of dengue and other mosquito-borne diseases?</p>
<p>This is where the <a href="https://blog.verily.com/2016/10/introducing-debug-project.html">Debug Project</a> comes in. A newly announced partnership between Verily (formerly <a href="http://bits.blogs.nytimes.com/2015/12/07/alphabets-life-sciences-business-has-a-new-name-verily/">Google Life Sciences</a>) and CSIRO, together with the University of Queensland and James Cook University, sets out to investigate how effective the release of <em>Wolbachia</em>-infected male mosquitoes is for mosquito control. Most importantly, the project will also be developing new technologies for the cost-effective mass rearing of mosquitoes. This is a critical step in being able to apply this approach to major cities impacted by mosquito-borne disease.</p>
<p>The early stages of the project will involve scientists releasing laboratory reared male mosquitoes and following them to see where and how far they fly, and how successfully they can track down and mate with local female mosquitoes. As well as demonstrating that this approach can actually reduce the overall mosquito population, the research will fill many of the gaps in our understanding of male mosquito biology. </p>
<p>The one thing we know is critical to upscaling any of these approaches is strong engagement with the local community. Without community support and participation, these projects are primed for failure. So, how would you feel about scientists releasing millions of “bacteria-infected male mosquitoes” in your neighbourhood? As the swathes of new non-biting males buzz around you and your house searching for females, please – don’t get out the bug spray.</p><img src="https://counter.theconversation.com/content/67447/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, 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>Nigel Beebe works for University and the CSIRO and receives funding from state governments, (WA Health), national (NHMRC), and international (National Institutes of Health, USA and Verily) funding bodies to carry our research on mosquito biology and control.
</span></em></p>Upscaling the success of emerging mosquito control technologies relies on automating the rearing and release of millions of mosquitoes. Australia is to become the testing ground for a novel strategy.Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of SydneyNigel Beebe, Associate professor, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/651632016-09-20T08:12:45Z2016-09-20T08:12:45ZCommon Australian mosquitoes can’t spread Zika<figure><img src="https://images.theconversation.com/files/137304/original/image-20160911-13367-12e344o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The outbreak of Zika virus in Brazil had Australian travellers on alert but transmission is only possible in tropical Queensland.</span> <span class="attribution"><span class="source">Cameron Webb</span>, <span class="license">Author provided</span></span></figcaption></figure><p><a href="http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0004959">New research</a> from Australian scientists shows common local mosquitoes aren’t able to spread Zika virus. This means Australia is unlikely to see a major outbreak of the disease. But a risk remains in northern Queensland.</p>
<p>Since the World Health Organisation’s declaration of a <a href="http://www.who.int/emergencies/zika-virus/en/">Public Health Emergency of International Concern</a> in February, due to the effects of Zika on pregnant women, authorities have been on high alert.</p>
<p>The concern was not just for travellers heading to regions experiencing outbreaks but for the potential for local mosquitoes to spread the disease when those travellers returned home. </p>
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<h2>How do mosquitoes spread viruses?</h2>
<p>Mosquitoes are not like dirty syringes, spreading viruses in droplets of blood from person to person. When a mosquito bites, <a href="https://theconversation.com/are-itchier-insect-bites-more-likely-to-make-us-sick-61422">she injects saliva to assist blood-sucking</a>. Unfortunately, mixed in with that spit can be a virus.</p>
<p>For the saliva to become infected, the mosquito must first bite a person or animal infected with a virus. As the mosquito becomes infected, the virus spreads throughout the body of the mosquito; from the legs to the head. </p>
<p>Inside the head are the mosquito’s salivary glands. When they become infected, they can pass on the virus to the next unsuspecting host. </p>
<p>From acquiring to passing on the virus, the process can take anywhere from a few days to a couple of weeks.</p>
<p>Working out which mosquitoes spread which viruses is critical to developing strategic responses to outbreaks of disease.</p>
<h2>Which mosquitoes currently spread Zika virus?</h2>
<p>Back in Uganda, <a href="http://wwwnc.cdc.gov/eid/article/15/9/09-0442_article">where Zika virus was first discovered</a>, it was spread by African forest-dwelling mosquitoes such as <em>Aedes africanus</em>. </p>
<p>Decades later, when the first substantial outbreak was reported on <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa0805715">Yap Island in the Federated States of Micronesia</a>, it was <em>Aedes hensilii</em>.</p>
<p>The relationship between mosquitoes and Zika virus hasn’t been well studied but there is general consensus that, internationally, the mosquito of greatest concern is likely <em>Aedes aegypti</em>. </p>
<p><em>Aedes aegypti</em> is the cockroach of the mosquito world. It loves water-filled containers around the home and it spreads yellow fever, dengue and chikungunya among others. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/137319/original/image-20160912-3763-sq1es2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/137319/original/image-20160912-3763-sq1es2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/137319/original/image-20160912-3763-sq1es2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/137319/original/image-20160912-3763-sq1es2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/137319/original/image-20160912-3763-sq1es2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/137319/original/image-20160912-3763-sq1es2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/137319/original/image-20160912-3763-sq1es2.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 <em>Aedes aegypti</em> loves to bite.</span>
<span class="attribution"><span class="source">Stephen Doggett</span></span>
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<p>It <a href="http://jme.oxfordjournals.org/content/38/3/411.abstract">loves biting people</a> – <a href="http://jme.oxfordjournals.org/content/30/1/94?ijkey=8fb3f2ab4cf539f1e3bec6808a1a4bab3a63ca7f&keytype2=tf_ipsecsha">lots of people</a>. Wherever <em>Aedes aegypti</em> is found, outbreaks of disease keep popping up.</p>
<p>Of the <a href="http://www.publish.csiro.au/pid/6391.htm">300 or so mosquitoes found in Australia</a>, only <em>Aedes aegypti</em> <a href="http://www.sciencedirect.com/science/article/pii/S1286457910000109">can spread exotic viruses</a> and it was considered the most likely to possibly spread Zika virus locally.</p>
<h2>Testing Aussie mozzies</h2>
<p>Australian mosquitoes have been tested against a range of exotic viruses including <a href="http://jme.oxfordjournals.org/content/36/4/508.abstract">dengue</a>, <a href="http://online.liebertpub.com/doi/abs/10.1089/vbz.2009.0106">chikungunya</a>, <a href="http://online.liebertpub.com/doi/abs/10.1089/vbz.2008.0037">West Nile</a>, <a href="http://jme.oxfordjournals.org/content/35/2/132.abstract">Rift Valley fever</a>, <a href="http://jme.oxfordjournals.org/content/40/1/82.abstract">Japanese encephalitis</a> and <a href="http://www.ajtmh.org/content/85/3/446.short">yellow fever</a> viruses.</p>
<p>But no-one had tested the ability of local mosquitoes to spread Zika virus – until now. </p>
<p>Scientists from Queensland Health, the University of Queensland and James Cook University studied the potential for Australian mosquitoes to spread Zika virus and found <em>Aedes aegypti</em> does indeed pose the greatest risk. The results are published today in the journal <a href="http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0004959">PLoS Neglected Tropical Diseases</a>.</p>
<p>The study tested seven types of mosquito implicated in the spread of disease in Australia, including <em>Aedes notoscriptus</em>, <em>Aedes vigilax</em>, <em>Culex annulirostris</em>, <em>Culex quinquefasciatus</em> and <em>Aedes aegypti</em>. These mosquitoes are frequent biters, are found close to local suburbs and have been shown to transmit other pathogens. </p>
<p>The researchers exposed groups of mosquitoes in the laboratory to blood infected with one of two strains of Zika virus: one originating from a traveller returning to Australia from the Pacific; another derived from the original strain isolated in Uganda.</p>
<p>Once the mosquitoes fed on the blood and virus mixture, they were tested to see if they become infected with the virus and, most importantly, whether the virus was being transmitted in their spit.</p>
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<img alt="" src="https://images.theconversation.com/files/138413/original/image-20160920-11103-10dnymd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/138413/original/image-20160920-11103-10dnymd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138413/original/image-20160920-11103-10dnymd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138413/original/image-20160920-11103-10dnymd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138413/original/image-20160920-11103-10dnymd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138413/original/image-20160920-11103-10dnymd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138413/original/image-20160920-11103-10dnymd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&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">Mosquito-control efforts should remain focused on <em>Aedes aegypti</em>.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-436043980/stock-photo-girl-with-blond-hair-sitting-with-his-back-turned-and-scratching-bitten-red-swollen-neck-skin-from-mosquito-bites-in-the-summer-in-the-forest-close-up-up-of-visible-insect-bites-irri.html?src=ugB6hK17vaGv0tjJn7RqDA-1-51">dimid_86/Shuterstock</a></span>
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<p>The only mosquito found to transmit Zika virus was, unsurprisingly, <em>Aedes aegypti</em>. </p>
<p>However, what was surprising was the relatively low rate of transmission. Fourteen days after taking a Zika virus-infected blood meal, only 67% of infected mosquitoes were found with virus in their saliva. Based on other mosquito-borne viruses, such as <a href="http://jvi.asm.org/content/88/11/6294.short">chikungunya</a>, it would be expected to be much higher. The result, however, echoes the results of <a href="http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0004543">another study from the United States</a>.</p>
<p><em>Aedes aegypti</em> is playing an important role in outbreaks of Zika virus but perhaps it is due to more than just their ability to transmit the virus. They have a propensity to bite humans, and to bite many different people. </p>
<p>Mosquito-control efforts <a href="http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0004993">should therefore remain focused</a> on <em>Aedes aegypti</em>.</p>
<h2>Is Australia safe from Zika?</h2>
<p>These results have important implications for predicting where in Australia we may see an outbreak of Zika virus.</p>
<p><em>Aedes aegypti</em> is generally only found in <a href="https://www.mja.com.au/journal/2009/190/5/dengue-and-climate-change-australia-predictions-future-should-incorporate?inline=true">tropical regions of Queensland</a>. The mosquito isn’t in the major urban area of Southeast Queensland such as Brisbane, Sunshine Coast or Gold Coast. The areas at <a href="https://www.health.qld.gov.au/publications/clinical-practice/guidelines-procedures/diseases-infection/governance/dengue-mgt-plan.pdf">greatest risk</a> are likely to be those around Cairns, Townsville as well as the Torres Strait. There is a moderate risk around Rockhampton and Gladstone. </p>
<p>The absence of <em>Aedes aegypti</em> from any of our major metropolitan regions means the risk of a major outbreak is extremely low. </p>
<p>But there is a risk of a minor disease outbreak where the <em>Aedes aegypti</em> is present. Every year, there are small local outbreaks of dengue in tropical Queensland; there’s a chance we’ll see similar outbreaks of Zika.</p>
<p>The good news is that authorities in tropical Queensland are well-equipped to deal with outbreaks of mosquito-borne disease. They have been <a href="https://www.health.qld.gov.au/publications/clinical-practice/guidelines-procedures/diseases-infection/governance/dengue-mgt-plan.pdf">responding to local outbreaks of dengue</a> for decades and are <a href="https://www.health.qld.gov.au/publications/clinical-practice/guidelines-procedures/diseases-infection/governance/chikungunya-management-plan.pdf">prepared for potential outbreaks of chikungunya</a>. The response to the threat of Zika virus remains essentially the same.</p>
<p>The potential for human to human sexual transmission of Zika virus remains a small but not insignificant risk for all regions of Australia. As <a href="http://apps.who.int/iris/bitstream/10665/204421/1/WHO_ZIKV_MOC_16.1_eng.pdf">international health authorities recommend</a>, travellers returning from countries experiencing outbreaks of Zika virus must use condoms or abstain from sex for six months. </p>
<p>If you’re planning to travel to a Zika-affected area, consult the <a href="http://smartraveller.gov.au/Pages/default.aspx">Smart Traveller website</a> for the most up-to-date information about the best ways to avoid mosquito bites.</p><img src="https://counter.theconversation.com/content/65163/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, 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 Francis van den Hurk works for Queensland Health, which funded the research. </span></em></p>New research shows common local mosquitoes aren’t able to spread Zika. This means Australia is unlikely to see a major outbreak of the disease. But a risk remains in northern Queensland.Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/640752016-08-17T19:01:13Z2016-08-17T19:01:13ZOne of the biggest vaccination drives ever is underway to beat yellow fever<figure><img src="https://images.theconversation.com/files/134476/original/image-20160817-3569-4p9kmp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A boy is vaccinated during an emergency campaign against yellow fever in the Democratic Republic of Congo.</span> <span class="attribution"><span class="source">Reuters/Kenny Katombe</span></span></figcaption></figure><p><em>A <a href="http://www.who.int/mediacentre/factsheets/fs100/en/">yellow fever</a> outbreak in parts of Angola and the Democratic Republic of Congo (DRC) has led to more than 400 deaths since December 2015. The United Nations has embarked on a massive vaccination campaign with the aim of reaching 14 million people. Jacqueline Weyer, senior medical scientist at South Africa’s National Institute of Communicable Diseases, explains the how and the why.</em></p>
<p><strong>What makes this vaccination campaign different or unique?</strong></p>
<p>This is one of the largest vaccination efforts to contain an ongoing outbreak ever undertaken. </p>
<p>The response to the yellow fever outbreak in Angola, which started in December 2015, has already been remarkable. More than 10 million people have been vaccinated in Luanda Province and other affected areas of the country since February. The effect is already evident. No new cases in the area were recorded in July and the first weeks of August. </p>
<p>But the outbreak has spread to the DRC. The current concern is for the evolving situation there as well as to prepare for possible flare ups of the disease in the coming rainy months.</p>
<p>The vaccination campaign has been expanded to increase coverage in Angola in the areas that border the DRC in particular, and then in the DRC’s affected areas. These are regarded as high risk areas for the transmission of the virus.</p>
<p><strong>What does it take logistically to vaccinate 14 million people?</strong></p>
<p>The vaccination programme requires <a href="http://www.cdc.gov/yellowfever/vaccine/">vaccines</a> as well as health care workers to administer them safely. There are also many people working in the background co-ordinating the programmes and logisticians planning the campaigns. This ensures that the right people go to the right places with the right tools.</p>
<p>The World Health Organisation is co-ordinating more than 50 global partners to contribute to the <a href="http://www.who.int/features/2016/yellow-fever-mass-vaccination-campaign/en/">vaccination drive</a> on various levels. It includes 17.3 million syringes, 41,000 health workers and volunteers and 8 000 different vaccination locations. These are often in hard-to-reach rural settings in the DRC’s capital Kinshasa and surrounds and along the Angola-DRC border. </p>
<p><strong>Why is it being done now?</strong></p>
<p>The yellow fever vaccination campaigns started in the Angolan capital Luanda soon after the outbreak was recognised earlier in 2016. Vaccination coverage in Angola has been variable but the intention was to target areas hit hardest by the first outbreak in the capital. </p>
<p>Cases of yellow fever have been reported in the DRC since March. Most were related to people who got the disease in Angola. But there is now <a href="http://www.who.int/emergencies/yellow-fever/mediacentre/qa/en/">mounting evidence</a> that the virus has spread to mosquito populations in certain areas of the country and is being transmitted locally. That’s why the current interventions are being mobilised.</p>
<p>Routine yellow fever vaccination is a part of national immunisation plans in yellow fever endemic countries. The outbreak highlights challenges in these programmes. This includes supplies of the vaccine: it takes a long time to manufacture and supplies are limited.</p>
<p>It also points to the fact that existing programmes need to be strengthened. This is to make sure that populations are protected from yellow fever and from other vaccine preventable disease.</p>
<p>People who get yellow fever may experience fever and general flu-like symptoms such as tiredness and body aches in their joints. They sometimes also complain of nausea, loss of appetite, vomiting and dizziness.</p>
<p>In some cases the infection will have a more serious effect on the body’s organs. This can be fatal. For example, the liver may be severely affected and the person may become jaundiced or yellow in colour. This is where the disease gets its name from. Some people may also start bleeding. This includes blood in their stools or urine, or oozing from needle puncture sites.</p>
<p><strong>Why the slow roll-out in Kinshasa?</strong></p>
<p>This is related to a confluence of different factors. The first yellow fever cases associated with the Angola outbreak was reported in the DRC in March 2016. As case numbers started to increase and epidemiological data became available, it became apparent that the virus was not only being imported from Angola but was also being transmitted locally.</p>
<p>Another challenge has been acquiring adequate volumes of vaccine to vaccinate on a larger scale especially in the face of the massive and sudden uptake of vaccine in Luanda. </p>
<p>The vaccine cannot be rapidly produced and up-scaling of production is problematic and time consuming. Because of this the World Health Organisation has <a href="http://www.who.int/mediacentre/news/statements/2016/yellow-fever-vaccine/en/">recommended</a> a dose sparing approach known as <a href="http://biorxiv.org/content/early/2016/07/25/053421">fractional dosing</a>. This requires the use of one-fifth of a dose of vaccine per vaccination. </p>
<p>The downside is that the fractioned dose allows for shorter term protection against the virus. The advantage is that the current outbreak can be managed and the immediate risk mitigated. But it will be important to provide a catch-up vaccination in the future to ensure long lasting immunity. This will also diminish the risk of future outbreaks. A full dose of the vaccine provides lifelong immunity.</p><img src="https://counter.theconversation.com/content/64075/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jacqueline Weyer 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 massive yellow fever vaccination campaign highlights why existing programmes need to be strengthened.Jacqueline Weyer, Senior Medical Scientist, National Institute for Communicable Diseases, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/606462016-06-19T14:55:13Z2016-06-19T14:55:13ZChikungunya epidemic casts its pall: what you should know<figure><img src="https://images.theconversation.com/files/125522/original/image-20160607-15021-1fv0im2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A patient with symptoms of the Chikungunya virus in a Dominican hospital. Outbreaks have been reported in Africa, Asia, Europe, and the Indian and Pacific Oceans</span> <span class="attribution"><span class="source">Reuters/Ricardo Rojas </span></span></figcaption></figure><p><em>Parts of Northern Kenya have been struck by an epidemic of chikungunya, a mosquito borne viral infection. Half of the population <a href="http://www.ipsnews.net/2016/06/stepping-up-the-fight-to-end-cholera-and-chikungunya-outbreaks-in-mandera-county-kenya/">in one Kenyan county</a> which borders Ethiopia and Somalia has come down with the infection. There’s real risk of travellers spreading it to new areas. Professor Collins Ouma from the <a href="https://www.afidep.org/">African Institute for Development Policy</a> in Nairobi answers some important questions about the outbreak.</em></p>
<p><strong>What is chikungunya? What are its common symptoms?</strong></p>
<p>Chikungunya virus is transmitted to humans through mosquito bites. The most common symptoms of the chikungunya virus infection are fever and joint pain. Other symptoms include headaches, muscle pain, joint swelling or a rash. In addition, other people develop sudden fever, chills, nausea and vomiting. </p>
<p>In Kiswahili, “chikungunya” means “that which contorts or bends up”. This refers to the contorted or stooped posture of patients who are afflicted with the severe joint pain (arthritis). This is one of the disease’s most common features.</p>
<p>Symptoms usually show between three and seven days after someone is bitten by an infected mosquito. There is no vaccine to prevent or medicine to treat the chikungunya virus infection. The only available method of prevention is through shielding from mosquito bites. Travellers visiting countries where there are cases of chikungunya virus should use insect repellent, wear long sleeves and pants and stay in places with air conditioning or that use window and door screens. </p>
<p><strong>Where is it likely to occur and why?</strong></p>
<p>There have been documented outbreaks in Africa, Asia, Europe, and the Indian and Pacific Oceans. There is an anticipated risk that the virus will be imported to new areas by infected travellers. By 2013, local transmission had been identified in 45 countries or territories throughout the Americas with more than 1.7 million suspected cases reported to the <a href="http://www.who.int/denguecontrol/arbo-viral/other_arboviral_chikungunya/en/">Pan American Health Organisation</a> from affected areas.</p>
<p>The mosquito vectors associated with large outbreaks of chikungunya are <a href="http://www.cdc.gov/dengue/resources/30jan2012/comparisondenguevectors.pdf">Aedes aegypti</a>, which is also associated with yellow fever, and <a href="http://www.cdc.gov/dengue/resources/30jan2012/comparisondenguevectors.pdf">Aedes albopictus</a>. Both are associated with dengue fever as well. Aedes aegypti is confined to the tropics and sub-tropics while the Aedes albopictus mainly live in temperate and even in colder regions. In recent times, Aedes albopictus has spread from Asia to areas in Africa, Europe and the Americas.</p>
<p>Typical of mosquito vectors, the Aedes albopictus thrives in a wider range of water-filled breeding sites than Aedes aegypti. This explains the abundance of Aedes albopictus in rural, peri-urban and shady areas. Aedes aegypti is more closely associated with human habitation and uses indoor breeding sites as well as the same artificial outdoor habitats as Aedes albopictus.</p>
<p>In Africa, several other mosquito vectors have also been implicated in disease transmission. There is also accumulating evidence that some animals such as non-primates, rodents, birds and small mammals may act as reservoirs to the <a href="http://www.who.int/mediacentre/factsheets/fs327/en/">disease</a>. </p>
<p><strong>What similarities or differences are there when compared to its now better known cousin <a href="https://theconversation.com/africa/topics/zika-virus">Zika</a>?</strong></p>
<p>Similar to chikungunya, the Zika virus is also primarily transmitted by biting Aedes aegypti female mosquitoes. It also has no preventive vaccines or medications and the only available treatment is supportive care of symptoms.</p>
<p><strong>What is the global response to chikungunya?</strong></p>
<p>The current responses to chikungunya are outlined by the <a href="http://www.who.int/mediacentre/factsheets/fs327/en/">World Health Organisation</a>. The response has several focus areas. These include:</p>
<ul>
<li><p>formulating evidence-based outbreak management plans, </p></li>
<li><p>providing technical support and guidance to manage cases and outbreaks in countries effectively, </p></li>
<li><p>supporting countries to improve their reporting systems, </p></li>
<li><p>providing training on clinical management, diagnosis and vector control at the local and regional level, and </p></li>
<li><p>publishing guidelines and handbooks on case management and vector control for World Health Organisation member states. </p></li>
</ul>
<p>There has been a heightened urgency to encourage affected countries to develop and maintain the capacity to detect and confirm cases, manage patients and implement social communication strategies to reduce the presence of the mosquito vectors. </p>
<p>Integrated vector control has mainly been through methods to reduce the source by eliminating all potential vector breeding places near the domestic or peri-domestic areas. Authorities have used larvicides to eliminate larvae and biological control. This is by, for instance, introducing fish that feed on the larvae in water tanks and other water sources.</p>
<p><strong>Has Kenya been able to meet these guidelines and deal with the epidemic?</strong> </p>
<p>The Kenyan government has responded quickly to prevent the spread of chikungunya. One of its approaches has been to strengthen health systems, especially those associated with a well-functioning surveillance. This ensures responses to disease outbreaks are versatile and resilient. </p>
<p>The government has also emphasised building the capacity of health staff, using community-driven prevention measures. These prepare the local systems for quick response before external support is mobilised. In addition, there are also enhanced public-private partnerships and cross-border collaborations to curb the spread of the virus before it becomes an epidemic. </p>
<p>The government has realised that to effectively control the virus, health institutions must be adequately equipped. They need to detect early signs of unusual disease patterns, track and investigate cases, and must be able to diagnose and confirm outbreaks promptly. </p>
<p>These approaches present an all-inclusive paradigm in health systems development that not only combat chikungunya but also other infectious diseases in Kenya and beyond.</p><img src="https://counter.theconversation.com/content/60646/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Collins Ouma 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>There is no vaccine to prevent or medicine to treat the chikungunya virus infection. The only available method of prevention is through shielding people from mosquito bites.Collins Ouma, Head of Research and Knowledge Translation at the African Institute for Development Policy and Professor, Maseno UniversityLicensed as Creative Commons – attribution, no derivatives.