tag:theconversation.com,2011:/global/topics/eradication-10468/articlesEradication – The Conversation2023-10-24T04:11:28Ztag:theconversation.com,2011:article/2124492023-10-24T04:11:28Z2023-10-24T04:11:28ZIndonesia needs to triple its funding to control tuberculosis – here’s where to start<figure><img src="https://images.theconversation.com/files/552901/original/file-20231010-24-za7ydt.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Image of a tuberculosis patient.
</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Tuberculosis#/media/File:Depiction_of_a_tuberculosis_patient.png">Myupchar/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Indonesia is still <a href="https://tbindonesia.or.id/wp-content/uploads/2023/02/Factsheet-Country-Profile-Indonesia-2022.pdf">struggling to fight tuberculosis (TB)</a>, with the second-highest number of cases worldwide.</p>
<p>In 2021, one study estimated Indonesia had a staggering incidence rate of TB <a href="https://rdi.or.id/wp-content/uploads/2023/08/Increasing-Financing-for-Tuberculosis-Programs-in-Indonesia.pdf">759 cases per 100,000 people</a> – more than double the World Health Organization’s 2021 estimate <a href="https://data.who.int/indicators/i/C288D13">354 cases per 100,000 Indonesians</a>. That compares with a global average of <a href="https://data.who.int/indicators/i/C288D13">134 per 100,000 people</a>.</p>
<p>Undeterred by the challenges posed by TB, Indonesia has set ambitious targets of reducing TB cases to <a href="https://tbindonesia.or.id/wp-content/uploads/2021/06/NSP-TB-2020-2024-Ind_Final_-BAHASA.pdf">190 per 100,000 individuals</a> by 2024 and to 65 per 100,000 by 2030. </p>
<p>With a staggering number of TB cases and those ambitious targets, the country urgently requires increased funding to combat this potentially deadly but preventable communicable disease. </p>
<p>Currently, insufficient funding is a significant obstacle in Indonesia to fight against TB. <a href="https://www.who.int/publications/digital/global-tuberculosis-report-2021/financing">Sustained adequate funding</a> would ensure the availability of essential resources, diagnostic tools, medications and healthcare services necessary to prevent, diagnose and treat TB effectively. </p>
<h2>Lack of funding risks more people getting sick</h2>
<p>Known as the <a href="https://www.who.int/publications/i/item/9789240013131">TB financing gap</a>, lack of funding can lead to inadequate diagnostic tools and equipment provision, resulting in delayed or inaccurate diagnoses. These delays have grave consequences.</p>
<p>Studies <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7558533/">have shown</a> delayed treatment of TB increases disease transmission, posing a greater risk to individuals and communities.</p>
<p>Worldwide, 1.6 million people died from TB in 2021, making it the <a href="https://www.who.int/news-room/fact-sheets/detail/tuberculosis#:%7E:text=A%20total%20of%201.6%20million,(above%20HIV%20and%20AIDS).">13th leading cause of death</a> – and the second leading infectious killer after COVID-19.</p>
<p>According to Indonesia’s national strategy, the country needs to spend <a href="https://tbindonesia.or.id/wp-content/uploads/2021/06/NSP-TB-2020-2024-Ind_Final_-BAHASA.pdf">Rp47.3 trillion (US$3 billion)</a> from 2020 to 2024 to control TB. However, the budget availability for that period is only around Rp15.7 trillion ($990 million). </p>
<p>Indonesia also lacks access to financing help pay for those extra control measures.</p>
<p>The <a href="https://www.who.int/publications/i/item/9789240013131">WHO Global Tuberculosis Report</a> said Indonesia needs US$429 million for TB prevention, diagnosis and treatment and US$87 million for tuberculosis care – a total of US$516 million. But it has only secured only US$111 million. </p>
<p>In fact, WHO data shows that since 2009, Indonesia has consistently <a href="https://rdi.or.id/wp-content/uploads/2023/08/Increasing-Financing-for-Tuberculosis-Programs-in-Indonesia.pdf">failed to meet the necessary TB financing requirements</a>, financing only 41% of the needed TB programs each year, on average.</p>
<p>This financing gap restricts the availability of essential medications for TB treatment. This issue is particularly concerning, as drug-resistant strains of TB are emerging, further complicating treatment efforts.</p>
<h2>The pandemic hit TB funding</h2>
<p>The COVID-19 pandemic has worsened the TB financing gap in Indonesia. </p>
<p>The government had to change its priorities during the pandemic, reallocating its health budget for COVID-19 treatment and mitigation efforts. </p>
<p>WHO said Indonesia’s TB funding decreased <a href="https://www.who.int/indonesia/news/campaign/tb-day-2022/fact-sheets">around 8.7% between 2019 and 2020</a>. </p>
<p>Upon closer examination,<a href="https://rdi.or.id/wp-content/uploads/2023/08/Increasing-Financing-for-Tuberculosis-Programs-in-Indonesia.pdf">Two significant reasons emerge</a> related to factors contributing to the funding gap. </p>
<p>First, the lack of adequate fund to cover the costs of TB services. This limits the reach and impact of programs. </p>
<p>There is also a tendency among patients to seek diagnosis and treatment at hospitals, rather than local primary healthcare centres and clinics. This leads to a heavier financial burden on the National Health Insurance system, because treatment costs in hospitals are more expensive.</p>
<p>Second, the lack of private sector involvement in diagnosis, reporting and treatment further compounds the problem, hindering progress. </p>
<h2>What should we do now?</h2>
<p>Increasing domestic financing for TB programs is crucial. </p>
<p>The Indonesian government should allocate a higher proportion of the national budget to prevent and control TB, as well as to conduct TB-related research. </p>
<p>Integrating externally-funded TB programs into the National Health Care system would ensure sustainability and align them with the national healthcare framework. </p>
<p>Strengthening the healthcare system is paramount, including bolstering the capacity and infrastructure of local health centres and clinics, training healthcare professionals, and improving diagnostic and treatment services. </p>
<p>Additionally, exploring innovative financing pathways – such as engaging the private sector through public-private partnerships and leveraging international funding mechanisms – could provide the necessary resources to drive progress.</p>
<p>Closing the TB financing gap is essential, not only to improve patients’ health, but to also safeguard the well-being and socioeconomic stability of communities as a whole. </p>
<p>Indonesia must pursue <a href="https://rdi.or.id/wp-content/uploads/2023/08/Increasing-Financing-for-Tuberculosis-Programs-in-Indonesia.pdf">strategic actions to overcome these challenges</a>.</p><img src="https://counter.theconversation.com/content/212449/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Para penulis tidak bekerja, menjadi konsultan, memiliki saham atau menerima dana dari perusahaan atau organisasi mana pun yang akan mengambil untung dari artikel ini, dan telah mengungkapkan bahwa ia tidak memiliki afiliasi di luar afiliasi akademis yang telah disebut di atas.</span></em></p>Indonesia has the world’s second-highest rates of TB – but lack of funding means not enough people are being diagnosed and treated fast enough.Rahmah Aulia Zahra, Children, Social Welfare, and Health Research Officer, Resilience Development Initiative (RDI)Wewin Wira Cornelis Wahid, Program Officer, Resilience Development Initiative (RDI)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1889892022-08-21T20:03:12Z2022-08-21T20:03:12ZThe latest polio cases have put the world on alert. Here’s what this means for Australia and people travelling overseas<figure><img src="https://images.theconversation.com/files/479994/original/file-20220818-459-q63sig.jpg?ixlib=rb-1.1.0&rect=1%2C1%2C997%2C664&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/covid-19-measles-ebola-vaccinated-doctor-2120184491">Shutterstock</a></span></figcaption></figure><p>Until recently, polio had only been detected in a handful of countries, thanks to global eradication efforts.</p>
<p>But this year’s polio alerts in the United States, United Kingdom and Israel are a reminder that as long as poliovirus is found anywhere, it is a potential problem everywhere. </p>
<p>That could include Australia.</p>
<p>Here’s what the latest polio cases mean for Australia – including under-vaccinated communities and people travelling internationally.</p>
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<h2>The US case</h2>
<p>In July this year, a young man in Rockland County, New York, developed paralysis and was diagnosed with polio, the <a href="https://www.statnews.com/2022/07/21/n-y-state-detects-polio-case-first-in-the-u-s-since-2013/">first US case since 2013</a>.</p>
<p>He had never been vaccinated against polio, which is not uncommon among <a href="https://forward.com/news/512089/polio-rockland-county-new-york-vaccine-orthodox-jew/">Orthodox Jewish people</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8549591/">in some countries</a>. Rockland County has the highest percentage of Orthodox Jewish people in the US. Currently, only <a href="https://health.ny.gov/diseases/communicable/polio/county_vaccination_rates.htm">about 60%</a> of children in the county are vaccinated against polio, compared with <a href="https://www.cdc.gov/nchs/fastats/immunize.htm">more than 90%</a> nationally.</p>
<p>As of August 12, poliovirus was <a href="https://www1.nyc.gov/site/doh/about/press/pr2022/nysdoh-and-nycdohm-wastewater-monitoring-finds-polio-urge-to-get-vaccinated.page">still being detected</a> in sewage in New York City and other counties in New York State, indicating the virus is still circulating in the community.</p>
<p>The reason there have been no further cases of paralysis reflects the fact that only around <a href="https://www.who.int/news-room/fact-sheets/detail/poliomyelitis">one in 200 people</a> infected by the virus develops paralysis. </p>
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Read more:
<a href="https://theconversation.com/polio-in-new-york-an-infectious-disease-doctor-explains-this-exceedingly-rare-occurrence-187518">Polio in New York – an infectious disease doctor explains this exceedingly rare occurrence</a>
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<h2>A child in Israel</h2>
<p>One <a href="https://twitter.com/propublica/status/1558140096028737539">indirect link</a> to the New York man may be in Jerusalem where, in March 2022, poliovirus <a href="https://www.who.int/emergencies/disease-outbreak-news/item/2022-DON366">was found</a> in sewage and <a href="https://www.nature.com/articles/s41564-022-01201-0">one case</a> of paralysis occurred in an unvaccinated child.</p>
<p>Vaccination rates among Ultra-Orthodox Jewish people in Israel have been historically low, including <a href="https://apnews.com/article/coronavirus-pandemic-health-middle-east-religion-israel-557e9d18f3f78f4fc141eeddaaefb8eb">low uptake</a> of COVID vaccines.</p>
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<h2>UK ramps up vaccination</h2>
<p>In June this year, the UK government <a href="https://www.gov.uk/government/news/poliovirus-detected-in-sewage-from-north-and-east-london">reported</a> wastewater surveillance in north and east London between February and May had identified poliovirus on consecutive occasions. </p>
<p>This indicated a provisional “silent” outbreak and prompted health officials to instigate catch-up vaccination campaigns. No cases of paralysis have been reported.</p>
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<p>This is reminiscent of an earlier “silent” outbreak of polio in 2013-2014 when, after decades without a case, Israel <a href="https://www.pnas.org/doi/10.1073/pnas.1808798115">detected</a> poliovirus in wastewater samples in many areas, mainly in southern regions.</p>
<p>Stool surveys indicated the outbreak was restricted mainly to children under the age of ten in the Bedouin population of <a href="https://pubmed.ncbi.nlm.nih.gov/27334457/">southern Israel</a>. The virus originated in Pakistan and arrived in Israel via Cairo and then, probably, through Bedouin communities in Egypt and Israel.</p>
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Read more:
<a href="https://theconversation.com/polio-vaccine-boosters-offered-to-london-children-an-expert-explains-whats-going-on-188564">Polio vaccine boosters offered to London children – an expert explains what's going on</a>
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<h2>Hang on, hasn’t polio been eradicated?</h2>
<p>It’s tempting to think polio has been eradicated. </p>
<p>The last case of locally acquired polio in Australia <a href="https://www1.health.gov.au/internet/main/publishing.nsf/Content/cda-pubs-cdi-2002-cdi2602-cdi2602l.htm">was in 1972</a>. Australia was declared polio-free on October 29, 2000, along with the other 36 countries in the Western Pacific Region of the World Health Organization. The last case reported in Australia <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2660702/">was in 2007</a>, when a student contracted the infection in Pakistan.</p>
<p>The <a href="https://polioeradication.org">Global Polio Eradication Initiative</a>, launched in 1988, successfully eliminated wild poliovirus from all but two countries – Pakistan and Afghanistan – where in recent years there have been very few cases. </p>
<p>In <a href="https://polioeradication.org/where-we-work/afghanistan/">Afghanistan</a>, there were four cases last year and one so far this year. In <a href="https://polioeradication.org/where-we-work/pakistan/">Pakistan</a>, there was one case in 2021 and 14 so far this year.</p>
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Read more:
<a href="https://theconversation.com/polio-were-developing-a-safer-vaccine-that-uses-no-genetic-material-from-the-virus-185721">Polio: we're developing a safer vaccine that uses no genetic material from the virus</a>
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<p>The recent cases and wastewater detected polioviruses in the UK, US and Israel are not the wild variety. Instead, they are derived from the oral polio vaccine.</p>
<p>When a child receives a dose of the oral vaccine, they excrete the virus in the stool for several weeks. In very rare cases, the vaccine-derived virus mutates to a form that causes paralysis. This form is called a circulating vaccine-derived poliovirus (cVDPV). This occurs only in populations where polio vaccine coverage is low.</p>
<p>Just recently, cVDPV was reported in the Democratic Republic of the Congo, Mozambique and Yemen, as well as in wastewater in five other countries.</p>
<p>Australia, like all high-income countries, does not use the oral polio vaccine. Instead, children receive <a href="https://immunisationhandbook.health.gov.au/contents/vaccine-preventable-diseases/poliomyelitis">injectable inactivated polio vaccine</a>, which prevents paralysis but does not prevent transmission of the virus. </p>
<p>This is why so-called silent outbreaks can occur in countries that use the injectable vaccine. This is when the virus spreads from child to child but does not cause paralysis.</p>
<h2>What are the implications for Australia?</h2>
<p>Given Australia’s open international borders, there is no reason why someone who has recently received the oral polio vaccine wouldn’t enter the country and excrete the virus.</p>
<p>In Australia, at the age of five, <a href="https://www.health.gov.au/node/38782/childhood-immunisation-coverage/current-coverage-data-tables-for-all-children#five-year-olds">about 95% of children</a> are fully vaccinated against polio. </p>
<p>However, there are places with lower vaccine coverage, such as <a href="https://www.theguardian.com/australia-news/2021/aug/14/when-covid-came-to-the-anti-vax-capital-of-australia">Byron Shire</a> in northern New South Wales, with lower rates of childhood vaccination, including against polio.</p>
<p>This vaccine-hesitant community is vulnerable to the introduction of polio and has had cases of diphtheria, whooping cough, measles and tetanus in recent years.</p>
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<p>Unlike some other Orthodox Jewish communities overseas, there is no evidence this community in Australia is more vaccine hesitant than other Australians.</p>
<h2>How do we look out for cases?</h2>
<p>For years, wastewater monitoring has been routinely implemented in many countries. This acts as an early warning system to identify and rapidly mitigate the spread of many pathogens, <a href="https://theconversation.com/sewage-surveillance-is-the-next-frontier-in-the-fight-against-polio-105012">including poliovirus</a>, hepatitis viruses and, recently, SARS-CoV-2 (the virus that causes COVID).</p>
<p>At wastewater treatment facilities, sewage from an entire region is combined. This allows scientists to <a href="https://www.nature.com/articles/s41564-022-01201-0">detect pathogens</a> at the population level and before anyone presents with symptoms.</p>
<p>In December 2017, Victoria’s environmental testing program <a href="https://www.health.vic.gov.au/media-releases/health-surveillance-system-detects-poliovirus">detected</a> a rare type of poliovirus in pre-treated sewage from the Western Treatment Plant in Melbourne. </p>
<p>No cases of paralytic polio were detected but all Victorians up to the age of 19 were offered three doses of vaccine, free of charge, as part of catch-up arrangements.</p>
<p>Australia’s poliovirus infection outbreak response plan <a href="https://www.health.gov.au/sites/default/files/documents/2022/05/poliovirus-infection-outbreak-response-plan-for-australia.pdf">focuses on</a> clinical surveillance (where health workers report suspected cases to health authorities) and laboratory investigations of people who present with acute paralysis. </p>
<p>While the plan refers to examples of wastewater surveillance overseas, it does not propose a specific strategy in Australia. </p>
<p>Other than Victoria, it is not clear where wastewater polio surveillance is being conducted in Australia.</p>
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<strong>
Read more:
<a href="https://theconversation.com/sewage-surveillance-is-the-next-frontier-in-the-fight-against-polio-105012">Sewage surveillance is the next frontier in the fight against polio</a>
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<h2>What happens next?</h2>
<p>Australia is just as vulnerable to importations of poliovirus – both wild and vaccine-derived – as any other country.</p>
<p>Australia should ensure routine wastewater surveillance for poliovirus is conducted, at least in metropolitan areas.</p>
<p>Community-based vaccination campaigns should be sensitively conducted in vaccine-hesitant communities, such as in Byron Shire, to achieve high coverage.</p>
<p>Education should also be provided through GPs to parents planning to travel to Jerusalem, New York City and Rockland County. They should ensure all travelling family members are fully vaccinated against polio. Visitors to Israel may be able to access a dose of oral polio vaccine in that country for their children (which will prevent them being infected) but this is not available in the US.</p>
<p>Poliovirus enters the body through the mouth, usually from hands contaminated with the stool of an infected person. So parents should also pay special attention to their children’s hand hygiene, particularly if travelling overseas to any of the locations mentioned.</p><img src="https://counter.theconversation.com/content/188989/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Toole receives funding from the National Health and Medical Research council.</span></em></p>Polio cases in the US, UK and Israel remind us that this could also happen in Australia. Here’s what we should watch out for.Michael Toole, Associate Principal Research Fellow, Burnet InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1875182022-07-22T21:53:50Z2022-07-22T21:53:50ZPolio in New York – an infectious disease doctor explains this exceedingly rare occurrence<figure><img src="https://images.theconversation.com/files/475697/original/file-20220722-18-x3p6wo.jpg?ixlib=rb-1.1.0&rect=2%2C0%2C1794%2C1196&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Polio is endemic only in Afghanistan and Pakistan in 2022.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/Polio/221757d74c22419095b557a6d3e4ab75/photo?Query=polio&mediaType=photo&sortBy=arrivaldatetime:desc&dateRange=Anytime&totalCount=1705&currentItemNo=2">Sarah Poser, Meredith Boyter Newlove/CDC via AP</a></span></figcaption></figure><p><em>The first case of polio in the U.S. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5779436/">since 2013</a> was announced by New York state <a href="https://health.ny.gov/press/releases/2022/2022-07-21_polio_rockland_county.htm">health officials on July 21, 2022</a>. The U.S. resident had not been vaccinated.</em></p>
<p><em>Polio was a common cause of paralysis in children before <a href="https://theconversation.com/lessons-from-how-the-polio-vaccine-went-from-the-lab-to-the-public-that-americans-can-learn-from-today-145604">safe and effective vaccines were invented</a> in the mid-20th century. Thanks to global vaccination campaigns, polio is now almost eradicated, with <a href="https://polioeradication.org/polio-today/polio-now/this-week/">only 13 cases of endemic wild poliovirus reported</a> in 2022 to date worldwide.</em></p>
<p><em>The New York patient reportedly contracted a form of polio that can be traced back to the live, but weakened, poliovirus used in the <a href="https://www.cdc.gov/vaccines/vpd/polio/public/index.html">oral polio vaccine</a>. This version of the vaccine has <a href="https://www.cdc.gov/media/pressrel/r990617.htm">not been used in the U.S. since 2000</a>. Health officials said the virus affecting the male patient, who has muscle weakness and paralysis, <a href="https://health.ny.gov/press/releases/2022/2022-07-21_polio_rockland_county.htm">likely originated somewhere overseas</a>, where oral vaccines are still administered.</em></p>
<p><em><a href="https://scholar.google.com/citations?user=6yMIM1MAAAAJ&hl=en&oi=ao">William Petri</a> is an infectious disease specialist and chair of the World Health Organization’s <a href="https://polioeradication.org/tools-and-library/current-research-areas/polio-research-committee/">Polio Research Committee</a>. Here he explains what <a href="https://www.cdc.gov/vaccines/vpd/polio/hcp/vaccine-derived-poliovirus-faq.html">vaccine-derived poliovirus</a> is and why the inactivated polio vaccine administered in the U.S. today can’t cause it.</em></p>
<h2>What are the two kinds of polio vaccine?</h2>
<p>Vaccines introduce a harmless version of a pathogen to your body. The idea is that <a href="https://www.cdc.gov/vaccines/hcp/conversations/understanding-vacc-work.html">they train your immune system</a> to fight off the real germ if you ever encounter it.</p>
<p>The oral polio vaccine, <a href="https://doi.org/10.1126/science.288.5471.1593">originally developed by Albert Sabin</a>, uses a live but weakened poliovirus that one swallows in a sugar cube or droplet. Scientists weaken – or attenuate – the virus so it can no longer cause disease. </p>
<p>The other kind of polio vaccine was <a href="https://doi.org/10.1126/science.288.5471.1593">originally developed by Jonas Salk</a>. It contains inactivated, dead virus. It is administered by an injection.</p>
<p>In the U.S., children receive the inactivated polio vaccine <a href="https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html">at 2, 4 and 6 months of age</a>. It provides nearly complete protection from paralytic polio.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/475699/original/file-20220722-12-3gho47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="adult hands administer a drop of medicine to a boy with open mouth" src="https://images.theconversation.com/files/475699/original/file-20220722-12-3gho47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/475699/original/file-20220722-12-3gho47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/475699/original/file-20220722-12-3gho47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/475699/original/file-20220722-12-3gho47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/475699/original/file-20220722-12-3gho47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/475699/original/file-20220722-12-3gho47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/475699/original/file-20220722-12-3gho47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A boy in Pakistan receives a dose of the oral polio vaccine.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/PakistanPolio/23a6599533e34577b64f4932393fa80a/photo?Query=polio&mediaType=photo&sortBy=arrivaldatetime:desc&dateRange=Anytime&totalCount=1705&currentItemNo=17">AP Photo/Muhammad Sajjad</a></span>
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<h2>How can the live vaccine lead to a case of polio?</h2>
<p>The weakened form of the live virus in the oral vaccine cannot cause disease. However, because the vaccine is given orally, the weakened virus is excreted in the feces and can <a href="https://www.who.int/news-room/questions-and-answers/item/poliomyelitis-vaccine-derived-polio">spread from someone who is vaccinated to their close contacts</a>. If the weakened virus circulates person to person for long enough, it can mutate and regain its ability to cause paralysis.</p>
<p>The <a href="https://www.who.int/news-room/questions-and-answers/item/poliomyelitis-vaccine-derived-polio">mutated virus can then infect people</a> in communities with poor sanitation and low vaccination rates, causing disease and even paralysis. </p>
<p>This is an exceedingly rare occurrence. With more than 10 billion doses of the oral polio vaccine administered since 2000, there have been <a href="https://polioeradication.org/polio-today/polio-now/this-week/circulating-vaccine-derived-poliovirus/">fewer than 800 cases of vaccine-derived polio</a> reported.</p>
<p>Apparently, the current patient in New York was somehow exposed to a mutated poliovirus that had been transmitted after vaccination overseas. Earlier this summer, routine surveillance spotted <a href="https://www.who.int/news/item/22-06-2022-vaccine-derived-poliovirus-type-2-(vdpv2)-detected-in-environmental-samples-in-london--uk">vaccine-derived poliovirus in London’s sewage system</a>, but no cases have been reported there. </p>
<h2>Why use the oral vaccine anywhere if it comes with this risk?</h2>
<p>There’s a positive aspect to the fact that the weakened live virus can circulate in the community once oral vaccine recipients shed it in their feces. Traveling a feces-to-oral route, it can <a href="https://polioeradication.org/polio-today/polio-prevention/the-vaccines/opv/">help induce immunity</a> even in people who weren’t directly vaccinated. The oral polio vaccine is also <a href="https://doi.org/10.1093/infdis/jiu128">cheaper and easier to administer</a> than inactivated polio vaccines.</p>
<p>Most importantly, the live-virus vaccine stops transmission of wild poliovirus in a way that the inactivated-virus vaccine does not. The <a href="https://doi.org/10.1126/science.abb8588">eradication of polio</a> in the Americas, Europe and Africa has been accomplished solely through the use of the live oral vaccine. Once polio has been wiped from a continent, then it is safe to stop using the oral live vaccine and use only the inactivated vaccine, <a href="https://www.cdc.gov/cpr/polioviruscontainment/diseaseandvirus.htm">which does prevent disease in recipients</a> and does not pose the rare risk of vaccine-derived paralytic polio.</p>
<p><a href="https://polioeradication.org/nopv2/">A new and safer oral polio vaccine</a> that has been engineered not to mutate is now <a href="https://doi.org/10.1126/science.abb8588">replacing the earlier live-virus vaccine</a>. Thus, even this extremely rare complication of polio vaccination should soon become a thing of the past.</p>
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<figcaption><span class="caption">WHO: Polio Eradication – Reaching Every Last Child.</span></figcaption>
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<h2>How close is the world to eradicating polio?</h2>
<p>Thanks to <a href="https://polioeradication.org">tremendous global effort</a>, two of the three viruses that cause polio have been eradicated. The world is now on the verge of eradicating the final one, wild poliovirus 1 (WPV1).</p>
<p><a href="https://polioeradication.org/polio-today/polio-now/this-week/">Today endemic polio is found</a> only in Pakistan, with 12 cases of paralytic polio so far in 2022, and Afghanistan, with just one case this year. Africa has two cases, imported from overseas, which are being contained by additional vaccination campaigns.</p>
<p>Once wild poliovirus has been eradicated from the planet, vaccination efforts may be able to switch to the inactivated polio vaccine, eliminating the risk of any future vaccine-derived cases.</p><img src="https://counter.theconversation.com/content/187518/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>William Petri receives research funding from the NIH and the Gates Foundation.</span></em></p>The oral polio vaccine – which is no longer given in the US – relies on a live but weakened virus that can actually be passed from person to person.William Petri, Professor of Medicine, University of VirginiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1507362020-11-26T21:11:21Z2020-11-26T21:11:21ZVictoria may have eliminated COVID-19, but eradication is a distant dream<p>Today Victoria satisfied a common definition of elimination for COVID-19, recording its 28th consecutive day of zero new cases. While there is no international definition of <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30633-2/fulltext">elimination</a>, two average incubation periods without community transmission is widely accepted as local elimination, especially in a geographically isolated country like Australia.</p>
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<p>It’s a remarkable achievement following a severe second wave which peaked at daily new case rates of around 700 in early August. But elimination is not eradication, and we can expect the virus to return at some point, as has happened in several countries that previously boasted minimal or no community transmission. </p>
<p>So how did Victoria get here, and what can it do to keep numbers as low as possible?</p>
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<h2>Elimination is not eradication</h2>
<p>There’s no universal definition of elimination. As applied to other infectious diseases such as polio and measles, it means a prolonged period of zero local transmission in a country or region. For measles, the World Health Organisation (WHO) is very exacting and <a href="https://www.who.int/publications/i/item/framework-for-verifying-elimination-of-measles-and-rubella">demands</a> no community transmission for 36 months.</p>
<p>With more than <a href="https://www.worldometers.info/coronavirus/#countries">500,000 new daily COVID cases</a> being reported globally, preventing new local transmission in Victoria will depend on the state building a virus-proof defence. </p>
<p>Several countries have shown the virus can return after a long period of minimal local transmission. The most pertinent example is <a href="https://theconversation.com/100-days-without-covid-19-how-new-zealand-got-rid-of-a-virus-that-keeps-spreading-across-the-world-143672">New Zealand</a>, which experienced 102 consecutive days of zero community transmission before a cluster cropped up in Auckland on August 11. Israel, South Korea, Vietnam and Hong Kong have also experienced reemergence of the virus following significant periods of minimal community transmission. And this month, we witnessed a cluster in suburban Adelaide that originated in a quarantine hotel, after South Australia had experienced many months of no community transmission. </p>
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Read more:
<a href="https://theconversation.com/of-all-the-places-that-have-seen-off-a-second-coronavirus-wave-only-vietnam-and-hong-kong-have-done-as-well-as-victorians-148520">Of all the places that have seen off a second coronavirus wave, only Vietnam and Hong Kong have done as well as Victorians</a>
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<p>Indeed elimination doesn’t mean the virus is completely gone. For example, Australia eliminated local transmission of polio in 1972. But it wasn’t until 30 years later, in 2002, that the WHO <a href="https://www1.health.gov.au/internet/main/publishing.nsf/Content/cda-pubs-cdi-2002-cdi2602-cdi2602l.htm">declared Australia polio-free</a>. </p>
<p>Almost 20 years after that declaration, we still can’t say we’ve eradicated polio because eradication refers to the global removal of a human pathogen; only <a href="https://www.cdc.gov/smallpox/history/history.html">smallpox has achieved that status</a>. One strain of the polio virus continues to circulate in Afghanistan and Pakistan. In 2007, a 22-year-old student from Pakistan was <a href="https://wwwnc.cdc.gov/eid/article/15/1/08-0791_article">diagnosed with polio</a> at Box Hill Hospital in Melbourne’s East.</p>
<h2>So, how did we get to zero?</h2>
<p>Since the grim height of Victoria’s second wave in July and August, several coordinated interventions have eventually borne fruit. One of the most important was the strengthening of the test-trace-isolate-support system. While details are emerging during the <a href="https://www.smh.com.au/national/victoria/sutton-tells-inquiry-contact-tracers-overwhelmed-as-daily-cases-hit-200-20201123-p56h3q.html">parliamentary inquiry into Victoria’s hotel quarantine system</a>, some of the features of this strengthening are known:</p>
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<li><p>decentralisation through regional hubs and metropolitan public health units</p></li>
<li><p>increased engagement and involvement of communities, through programs aimed at public housing estates and local initiatives <a href="https://www.abc.net.au/news/2020-09-09/gps-altona-north-band-together-covid-19-surge-contact-tracing/12642014">led by GPs</a> and community health centres</p></li>
<li><p>adoption of “upstream” contact tracing, identifying contacts of index cases before they developed symptoms as well as after developing symptoms. In both groups, contacts of contacts were identified. This led to the rapid control of clusters such as those in Kilmore and Shepparton. </p></li>
</ul>
<p>Other important initiatives included the joint federal-state <a href="https://www.health.gov.au/initiatives-and-programs/victorian-aged-care-response-centre">Victorian Aged Care Response Centre</a>, which eventually managed the explosive outbreaks in residential aged care facilities, and more effective infection prevention and control in health-care settings. </p>
<p>And there were the containment measures that kept people from intermingling. Stage 3 restrictions were reimposed on July 8, limiting the reasons people could leave home. A study <a href="https://www.mja.com.au/journal/2020/victorias-response-resurgence-covid-19-has-averted-9000-37000-cases-july-2020">published in early August</a> found these restrictions averted between 9,000 and 37,000 cases. From July 23, masks were mandatory at all times outside the home. On August 2, stage 4 restrictions and a night curfew effectively shut down Melbourne. From then on, the number of new cases steadily declined. </p>
<p>Perhaps the greatest achievement of Victoria’s response was to maintain a strong health focus amid a chorus of criticism, much of it from Canberra or the Sydney-based media, pushing the “economy first” mantra. In fact, <a href="https://ourworldindata.org/covid-health-economy">data show</a> countries that managed to protect the health of their citizens have generally protected their economy more effectively. </p>
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Read more:
<a href="https://theconversation.com/data-from-45-countries-show-containing-covid-vs-saving-the-economy-is-a-false-dichotomy-150533">Data from 45 countries show containing COVID vs saving the economy is a false dichotomy</a>
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<h2>How can we stay where we are?</h2>
<p>The first requirement is an effective quarantine system for returned travellers. With cases surging globally, the proportion of travellers who are infected will increase significantly from the <a href="https://www.abc.net.au/news/2020-10-30/future-of-coronavirus-hotel-quarantine-may-be-less-onerous/12828286">0.7% reported</a> between March and August. This will require arrangements that employ well-trained and adequately paid workers who are regularly monitored by infection control and occupational health and safety experts. The <a href="https://www.abc.net.au/news/2020-11-19/victoria-records-no-coronavirus-cases-and-no-deaths/12898618">advance contact tracing</a>, which will identify the close contacts of staff before they might test positive for the virus, announced by Premier Daniel Andrews would be a useful adjunct as long as confidentiality is assured.</p>
<p>Crucially, experienced teams of contact tracers must be on standby. They need to maintain the rigorous standards developed over the past few months and engage in simulation exercises that test their capacities. They must retain a focus on community trust and avoid the vilification of individuals that <a href="https://www.theage.com.au/national/blaming-and-shaming-breaks-a-cardinal-rule-of-public-health-20201121-p56gpa.html">marred the South Australian response</a>.</p>
<p>What’s more, the state must sustain proven containment measures such as physical distancing, hand hygiene, masks indoors, and getting tested if you have symptoms.</p>
<p>Australia is an almost COVID-free oasis, surrounded by a tsunami of virus. Maintaining this status for the next six months or so, while at the same time opening up, will be a huge challenge. Recent responses in Victoria, NSW and SA suggest we are up to it.</p>
<p>And as the story of the <a href="https://www.abc.net.au/news/2020-11-23/adelaide-coronavirus-heroine-doctor-dharminy-thurairatnam-speaks/12910074">sharp-eyed doctor in Adelaide</a> showed us — when she tested a patient in the emergency room who’d initially felt “weak” but had very few COVID symptoms, alerting authorities to the previously silent spread of the virus — to maintain elimination we’re also going to need a little luck. </p>
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Read more:
<a href="https://theconversation.com/south-australias-6-day-lockdown-shows-we-need-to-take-hotel-quarantine-more-seriously-150368">South Australia's 6-day lockdown shows we need to take hotel quarantine more seriously</a>
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<img src="https://counter.theconversation.com/content/150736/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Toole has received funding from the federal government. He is affiliated with the Burnet Institute which has also received funding from the federal and state governments. </span></em></p>Victoria has achieved a remarkable thing. But the virus has not been eradicated. The question then becomes, how well can the state deal with new outbreaks?Michael Toole, Professor of International Health, Burnet InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1424952020-07-15T20:03:09Z2020-07-15T20:03:09ZEradication, elimination, suppression: let’s understand what they mean before debating Australia’s course<p>The current surge in community transmission of COVID-19 <a href="https://www.dhhs.vic.gov.au/coronavirus-update-victoria-14-july-2020">in Victoria</a> has brought renewed discussion of whether Australia should maintain its current “suppression” strategy, or pursue an “elimination” strategy instead. </p>
<p>But what do these terms actually mean, and what are the differences between the two?</p>
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Read more:
<a href="https://theconversation.com/as-restrictions-ease-here-are-5-crucial-ways-for-australia-to-stay-safely-on-top-of-covid-19-138000">As restrictions ease, here are 5 crucial ways for Australia to stay safely on top of COVID-19</a>
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<h2>In theory</h2>
<p>Disease eradication means a <a href="https://www.cdc.gov/mmwr/preview/mmwrhtml/su48a7.htm">global absence</a> of the pathogen (except in laboratories). We achieved this for <a href="https://www.who.int/csr/disease/smallpox/en/">smallpox</a> in 1980. Diseases suitable for eradication are usually those where humans are the only host, and where there’s an effective vaccine or other prevention strategy. </p>
<p>Disease elimination relates to <a href="https://www.cdc.gov/mmwr/preview/mmwrhtml/su48a7.htm">a country or a region</a>, and is usually defined as the absence of ongoing community (endemic) transmission. </p>
<p>Elimination generally sits in the context of a <a href="https://www.who.int/bulletin/volumes/84/2/editorial10206html/en/">global eradication goal</a>. The World Health Organisation sets a goal for eradication, and countries play their part by first achieving country-wide elimination. </p>
<p>Cases and small outbreaks may still occur once a disease is eliminated — imported through travel — but these don’t lead to sustained community transmission. </p>
<p>Finally, disease <a href="https://apps.who.int/iris/bitstream/handle/10665/260633/PMC2305684.pdf?sequence=1&isAllowed=y">control</a> refers to deliberate efforts to reduce the number of cases to a locally acceptable level, but community transmission may still occur. Australia’s current suppression strategy, though seeking to quash community transmission, can be classified as disease control.</p>
<h2>In practice</h2>
<p>Elimination and suppression strategies employ the same control measures. For COVID-19, these <a href="https://theconversation.com/as-restrictions-ease-here-are-5-crucial-ways-for-australia-to-stay-safely-on-top-of-covid-19-138000">include</a>:</p>
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<li><p>rapid identification and isolation of cases</p></li>
<li><p>timely and comprehensive contact tracing</p></li>
<li><p>testing and quarantining of contacts</p></li>
<li><p>varying degrees of social distancing (lockdown, banning mass gatherings, keeping 1.5m distance from others)</p></li>
<li><p>border controls: restricting entry through <a href="https://academic.oup.com/jtm/article/doi/10.1093/jtm/taaa081/5842100">travel bans</a>, and quarantine of returning international travellers</p></li>
<li><p>face masks to <a href="https://theconversation.com/victorians-and-anyone-else-at-risk-should-now-be-wearing-face-masks-heres-how-to-make-one-141980">reduce transmission</a>. </p></li>
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Read more:
<a href="https://theconversation.com/grattan-on-friday-does-victorias-second-wave-suggest-we-should-debate-an-elimination-strategy-142374">Grattan on Friday: Does Victoria's second wave suggest we should debate an elimination strategy?</a>
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<p>The differences between a suppression strategy and an elimination strategy are the strictness, timing, and duration with which these measures are applied, especially travel restrictions. </p>
<p>For example, under a suppression strategy, physical distancing requirements might be lifted while there’s still a low level of community transmission. But under an elimination strategy, these measures would remain in place until there’s no detectable community transmission.</p>
<h2>What’s realistic for COVID-19?</h2>
<p>First, the prospect of eradicating COVID-19 is likely <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30129-8/fulltext">no longer feasible</a>, even with a vaccine. </p>
<p>People without symptoms may be able to spread COVID-19, which makes it difficult to identify every infectious case (SARS, for example, was only spread by people with symptoms). And if the virus has <a href="https://www.nature.com/articles/d41586-020-01449-8">an animal host</a>, animal reservoirs would also need to be eradicated.</p>
<p>So what about elimination?</p>
<p>For measles, <a href="https://apps.who.int/iris/handle/10665/207664">elimination is defined</a> as the absence of endemic measles transmission for more than 12 months. Countries <a href="https://www.who.int/bulletin/volumes/87/1/07-046375.pdf">must demonstrate</a> low incidence, high quality surveillance and high population immunity. </p>
<p>Imported cases in unvaccinated returning travellers and occasional small outbreaks continue to occur, but a country will lose its elimination status if community spread lasts longer than one year. </p>
<p>The majority of the Australian population are <a href="https://www.who.int/bulletin/volumes/87/1/07-046375.pdf">immune to measles</a>, which lowers the probability of sustained outbreaks. But most Australians remain susceptible to COVID-19.</p>
<p>So future sustained outbreaks, like the current Victorian outbreak, will remain possible until we can vaccinate the population — even under an elimination strategy.</p>
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Read more:
<a href="https://theconversation.com/lockdown-relax-repeat-how-cities-across-the-globe-are-going-back-to-coronavirus-restrictions-142425">Lockdown, relax, repeat: how cities across the globe are going back to coronavirus restrictions</a>
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<p>Like we have with measles, for COVID-19, we need a definition of elimination with specific criteria that can be measured.</p>
<p>Declaring COVID-19 “eliminated” after the absence of community transmission for a few weeks means little during a pandemic, and may lead to complacency in the community. This period should be more like a few months.</p>
<h2>Effective suppression can lead to elimination</h2>
<p>While the federal government continues to advocate for <a href="https://www.theguardian.com/australia-news/2020/jul/15/scott-morrison-says-we-cant-shut-down-australia-to-contain-second-wave-of-covid-19">its suppression strategy</a>, some states have demonstrated absence of community transmission.</p>
<p>International arrivals to these states (and to New Zealand) are <a href="https://www.abs.gov.au/ausstats/abs@.nsf/Latestproducts/3401.0Main%20Features3May%202020?opendocument&tabname=Summary&prodno=3401.0&issue=May%202020&num=&view=">comparatively small</a>, and the virus was always going to be more difficult to contain in cities with substantial international arrivals and high population densities, such as Sydney and Melbourne.</p>
<p>To achieve and sustain national elimination of any infectious disease during a pandemic is ambitious. It requires an epidemiologic definition with measurable criteria, significant resources and almost complete closure of international borders.</p>
<p>But maintaining the right for Australian citizens and residents to return to Australia means the borders are never fully closed, whether under a suppression strategy or elimination strategy.</p>
<p>So ultimately, both strategies are susceptible to outbreaks of COVID-19 in the community as long as the pandemic endures.</p>
<h2>It will always ebb and flow</h2>
<p>An elimination strategy would not necessarily have prevented the current outbreak in Victoria, particularly if social distancing restrictions had already been lifted. </p>
<p>Whether Australia continues with its suppression strategy or opts to switch to a defined elimination strategy, either approach will require continued vigilance. This could include intermittent reinstating of restrictions or targeted containment around hotspots as transmission ebbs and flows.</p>
<p>And whatever name we give to Australia’s approach, neither Victoria or New South Wales have accepted any level of community transmission. Both have gone hard to stop community outbreaks that have arisen, and that’s a good thing. </p>
<p>But long-term maintenance of periods of elimination are unlikely to be possible until we have a vaccine.</p>
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Read more:
<a href="https://theconversation.com/which-face-mask-should-i-wear-142373">Which face mask should I wear?</a>
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<img src="https://counter.theconversation.com/content/142495/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Anita Heywood has received funding from the ARC and NHMRC. In the past five years, she has received funding from GSK for investigator-driven grant funding related to immunisation for international travel. </span></em></p><p class="fine-print"><em><span>C Raina MacIntyre receives funding from NHMRC (Centre for Research Excellence and Principal Research Fellowship) and Medical Research Futures Fund. She has received funding from Seqirus and Sanofi for influenza research in the past five years.</span></em></p>Experts are currently debating whether Australia should pursue its current suppression strategy, or switch to an elimination strategy instead. But how different are the two?Anita Heywood, Associate Professor, UNSW SydneyC Raina MacIntyre, Professor of Global Biosecurity, NHMRC Principal Research Fellow, Head, Biosecurity Program, Kirby Institute, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1410322020-06-30T12:19:30Z2020-06-30T12:19:30ZThe US isn’t in a second wave of coronavirus – the first wave never ended<figure><img src="https://images.theconversation.com/files/344629/original/file-20200629-155345-y2nrtn.jpg?ixlib=rb-1.1.0&rect=5%2C44%2C3482%2C2439&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The U.S. as a whole is facing a huge surge in coronavirus cases, but the differences between states like New York and Florida are striking.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/man-wears-a-face-mask-as-he-check-his-phone-in-times-square-news-photo/1207979953?adppopup=true">Kena Betancur/1207979953 via Getty Images</a></span></figcaption></figure><p>After sustained declines in the number of COVID-19 cases over recent months, restrictions are starting to <a href="https://nymag.com/intelligencer/2020/06/failed-us-reopening-serves-up-a-feast-for-the-coronavirus.html">ease across the United States</a>. Numbers of new cases are falling or stable at low numbers in some states, but they <a href="https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html">are surging in many others</a>. Overall, the U.S. is experiencing a sharp increase in the number of new cases a day, and by late June, had surpassed the peak rate of spread in early April. </p>
<p>When seeing these increasing case numbers, it is reasonable to wonder if this is the <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30845-X/fulltext">dreaded second wave of the coronavirus</a> – a resurgence of rising infections after a reduction in cases.</p>
<p>The U.S. as a whole is not in a second wave because the first wave never really stopped. The virus is simply spreading into new populations or resurging in places that let down their guard too soon.</p>
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<h2>To have a second wave, the first wave needs to end</h2>
<p>A wave of an infection describes a large rise and fall in the number of cases. There isn’t a precise epidemiological definition of when a wave begins or ends. </p>
<p>But with talk of a <a href="https://www.theguardian.com/world/2020/jun/27/new-covid-19-clusters-across-world-spark-fear-of-second-wave">second wave in the news</a>, as an <a href="https://www.american.edu/cas/faculty/mhawkins.cfm">epidemiologist and public health researcher</a>, I think there are two necessary factors that must be met before we can colloquially declare a second wave. </p>
<p>First, the virus would have to be controlled and transmission brought down to a very low level. That would be the end of the first wave. Then, the virus would need to reappear and result in a large increase in cases and hospitalizations. </p>
<p>Many countries in <a href="https://doi.org/10.1038/s41562-020-0908-8">Europe and Asia have successfully ended the first wave</a>. <a href="https://www.theguardian.com/world/2020/jun/08/new-zealand-abandons-covid-19-restrictions-after-nation-declared-no-cases">New Zealand</a> and <a href="https://www.newyorker.com/magazine/2020/06/08/how-iceland-beat-the-coronavirus">Iceland</a> have also made it through their first waves and are now essentially coronavirus-free, with very low levels of community transmission and only a handful of active cases currently. </p>
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<p>In the U.S., cases spiked in March and April and then trended downward due to social distancing guidance and implementation. However, the U.S. never reduced spread to low numbers that were sustained over time. Through May and early June, numbers plateaued at <a href="https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html">approximately 25,000 new cases daily</a>.</p>
<p>We have left that plateau. Since mid-June, cases have been surging upwards. Additionally, the percentage of COVID-19 tests that are returning positive <a href="https://coronavirus.jhu.edu/testing/individual-states/arizona">is climbing steeply</a>, indicating that the increase in new cases is not simply a result of more testing, but the result of an increase in spread. </p>
<p>As of writing this, new deaths per day <a href="https://www.nbcnews.com/health/health-news/coronavirus-deaths-united-states-each-day-2020-n1177936">have not begun to climb</a>, but some hospitals’ intensive care units have <a href="https://www.newsweek.com/texass-largest-hospital-reaches-100-percent-icu-capacity-1513481">recently reached full capacity</a>. In the beginning of the outbreak, deaths often lagged behind confirmed infections. It is likely, as Anthony Fauci, the nation’s top infectious-disease specialist said on June 22, that <a href="https://www.washingtonpost.com/health/coronavirus-deaths-lag-behind-surging-infections-but-may-catch-up-soon/2020/06/24/22263b50-b620-11ea-a510-55bf26485c93_story.html">deaths will soon follow the surge in new cases</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/344632/original/file-20200629-155303-f53zoh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/344632/original/file-20200629-155303-f53zoh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/344632/original/file-20200629-155303-f53zoh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/344632/original/file-20200629-155303-f53zoh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/344632/original/file-20200629-155303-f53zoh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/344632/original/file-20200629-155303-f53zoh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/344632/original/file-20200629-155303-f53zoh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/344632/original/file-20200629-155303-f53zoh.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">After months of strict social distancing rules, New York has reduced its new cases to a fraction of what they were in April and is still being cautious.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/NYC-enters-Phase-2-Reopening-6-26-20/0d49884b9787416b92c0e5607d154fa4/128/0">John Nacion/STAR MAX/IPx 2020/AP Images</a></span>
</figcaption>
</figure>
<h2>Different states, different trends</h2>
<p>Looking at U.S. numbers as a whole hides what is really going on. Different states are in <a href="https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html">vastly different situations right now</a> and when you look at states individually, four major categories emerge.</p>
<ol>
<li><p>Places where the first wave is ending: States in the Northeast and a few scattered elsewhere experienced large initial spikes but were able to mostly contain the virus and substantially brought down new infections. <a href="https://www.nytimes.com/interactive/2020/us/new-york-coronavirus-cases.html">New York</a> is a good example of this. </p></li>
<li><p>Places still in the first wave: Several states in the South and West – see <a href="https://www.nytimes.com/interactive/2020/us/texas-coronavirus-cases.html">Texas</a> and <a href="https://www.nytimes.com/interactive/2020/us/california-coronavirus-cases.html">California</a> – had some cases early on, but are now seeing massive surges with no sign of slowing down. </p></li>
<li><p>Places in between: Many states were hit early in the first wave, managed to slow it down, but are either at a plateau – like <a href="https://www.nytimes.com/interactive/2020/us/north-dakota-coronavirus-cases.html">North Dakota</a> – or are now seeing steep increases – like <a href="https://www.nytimes.com/interactive/2020/us/oklahoma-coronavirus-cases.html">Oklahoma</a>.</p></li>
<li><p>Places experiencing local second waves: Looking only at a state level, <a href="https://www.nytimes.com/interactive/2020/us/hawaii-coronavirus-cases.html">Hawaii</a>, <a href="https://www.nytimes.com/interactive/2020/us/montana-coronavirus-cases.html">Montana</a> and <a href="https://www.nytimes.com/interactive/2020/us/alaska-coronavirus-cases.html">Alaska</a> could be said to be experiencing second waves. Each state experienced relatively small initial outbreaks and was able to reduce spread to single digits of daily new confirmed cases, but are now all seeing spikes again.</p></li>
</ol>
<p>The trends aren’t surprising based on how states have been dealing with reopening. The virus will go wherever there are susceptible people and until the U.S. stops community spread across the entire country, the first wave isn’t over. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/344634/original/file-20200629-155330-davgh7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/344634/original/file-20200629-155330-davgh7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/344634/original/file-20200629-155330-davgh7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/344634/original/file-20200629-155330-davgh7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/344634/original/file-20200629-155330-davgh7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/344634/original/file-20200629-155330-davgh7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/344634/original/file-20200629-155330-davgh7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/344634/original/file-20200629-155330-davgh7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The 1918 flu came back with a vengeance after a mutation and lack of preparedness set the stage for tens of millions of deaths during the second wave.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/image-shows-warehouses-that-were-converted-to-keep-the-news-photo/520830329?adppopup=true">Universal History Archive/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<h2>What could a second wave look like?</h2>
<p>It is possible – though at this point it seems unlikely – that the U.S. could control the virus before a vaccine is developed. If that happens, it would be time to start thinking about a second wave. The question of what it might look like depends in large part on everyone’s actions. </p>
<p>The <a href="https://dx.doi.org/10.1086%2F592454">1918 flu pandemic</a> was characterized by a mild first wave in the winter of 1917-1918 that went away in summer. After restrictions were lifted, people very quickly went back to pre-pandemic life. But a second, deadlier strain came back in fall of 1918 and third in spring of 1919. In total, <a href="https://www.cdc.gov/flu/pandemic-resources/1918-commemoration/1918-pandemic-history.htm">more than 500 million people were infected</a> worldwide and upwards of <a href="https://theconversation.com/compare-the-flu-pandemic-of-1918-and-covid-19-with-caution-the-past-is-not-a-prediction-138895">50 million died</a> over the course of three waves.</p>
<p>It was the combination of a quick return to normal life and a mutation in the flu’s genome that made it more deadly that led to the horrific second and third waves.</p>
<p>Thankfully, the coronavirus appears to be much more <a href="https://doi.org/10.1016/j.meegid.2020.104351">genetically stable</a> than the influenza virus, and thus less likely to mutate into a more deadly variant. That leaves human behavior as the main risk factor. </p>
<p>Until a <a href="https://theconversation.com/what-needs-to-go-right-to-get-a-coronavirus-vaccine-in-12-18-months-136816">vaccine or effective treatment is developed</a>, the tried-and-true public health measures of the last months – <a href="https://theconversation.com/this-simple-model-shows-the-importance-of-wearing-masks-and-social-distancing-140423">social distancing,</a> <a href="https://theconversation.com/masks-help-stop-the-spread-of-coronavirus-the-science-is-simple-and-im-one-of-100-experts-urging-governors-to-require-public-mask-wearing-138507">universal mask wearing</a>, frequent hand-washing and avoiding crowded indoor spaces – are the ways to stop the first wave and thwart a second one. And when there are surges like what is happening now in the U.S., further reopening plans need to be put on hold.</p><img src="https://counter.theconversation.com/content/141032/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Melissa Hawkins receives funding from USDA. </span></em></p>The recent spike in new coronavirus cases in the US is not due to a second wave, but simply the virus moving into new populations or surging in places that opened up too soon.Melissa Hawkins, Professor of Public Health, Director of Public Health Scholars Program, American UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1379912020-05-07T19:54:27Z2020-05-07T19:54:27ZWe may well be able to eliminate coronavirus, but we’ll probably never eradicate it. Here’s the difference<figure><img src="https://images.theconversation.com/files/333283/original/file-20200507-49550-1c69zdn.jpg?ixlib=rb-1.1.0&rect=11%2C5%2C3879%2C2205&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>Compared to many other countries around the world, Australia and New Zealand have done an exceptional job controlling COVID-19. </p>
<p>As of May 7, there were <a href="https://www.health.gov.au/news/health-alerts/novel-coronavirus-2019-ncov-health-alert/coronavirus-covid-19-current-situation-and-case-numbers">794 active cases</a> of COVID-19 in Australia. Only 62 were in hospital.</p>
<p>The situation in New Zealand is similar, with <a href="https://www.health.govt.nz/our-work/diseases-and-conditions/covid-19-novel-coronavirus/covid-19-current-situation/covid-19-current-cases">136 active cases</a>, only two of whom are in hospital.</p>
<p>If we continue on this path, could we eliminate COVID-19 from Australia and New Zealand?</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/yes-were-flattening-the-coronavirus-curve-but-modelling-needs-to-inform-how-we-start-easing-restrictions-135832">Yes, we're flattening the coronavirus curve but modelling needs to inform how we start easing restrictions</a>
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<hr>
<h2>Control –> elimination –> eradication</h2>
<p>In order to answer this question, we first to need to understand what elimination means in the context of disease, and <a href="https://www.cdc.gov/mmwr/preview/mmwrhtml/su48a7.htm">how it differs</a> from control and eradication.</p>
<p><strong>Disease control</strong> is when we see a reduction in disease incidence and prevalence (new cases and current cases) as a result of public health measures. The reduction does not mean to zero cases, but rather to an acceptable level. </p>
<p>Unfortunately, there’s no consensus on what is acceptable. It can differ from disease to disease and from jurisdiction to jurisdiction.</p>
<p>As an example, there were only <a href="https://immunisationhandbook.health.gov.au/vaccine-preventable-diseases/measles">81 cases of measles</a> reported in Australia in 2017. Measles is considered under control in Australia. </p>
<p>Conversely, measles is not regarded as controlled in New Zealand, where there was an outbreak in 2019. From January 1, 2019, to February 21, 2020, New Zealand recorded <a href="https://surv.esr.cri.nz/PDF_surveillance/MeaslesRpt/2020/measlesReport20200224.pdf">2,194 measles cases</a>. </p>
<p>For <strong>disease elimination</strong>, there must be zero new cases of the disease in a defined geographic area. There is no defined time period this needs to be sustained for – it usually depends on the incubation period of the disease (the time between being exposed to the virus and the onset of symptoms).</p>
<p>For example, the South Australian government is looking for 28 days of no new coronavirus cases (twice the <a href="https://theconversation.com/how-long-are-you-infectious-when-you-have-coronavirus-135295">incubation period</a> of COVID-19) before they will consider it eliminated.</p>
<p>Even when a disease has been eliminated, we continue intervention measures such as border controls and surveillance testing to ensure it doesn’t come back. </p>
<p>For example, in Australia, we have successfully eliminated <a href="https://theconversation.com/australia-has-eliminated-rubella-but-that-doesnt-mean-it-cant-come-back-106056">rubella</a> (German measles). But we maintain an immunisation schedule and disease surveillance program.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-zealands-coronavirus-elimination-strategy-has-united-a-nation-can-that-unity-outlast-lockdown-135040">New Zealand's coronavirus elimination strategy has united a nation. Can that unity outlast lockdown?</a>
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</em>
</p>
<hr>
<p>Finally, <strong>disease eradication</strong> is when there is zero incidence worldwide of a disease following deliberate efforts to get rid of it. In this scenario, we no longer need intervention measures.</p>
<p>Only two infectious diseases have been declared eradicated by the World Health Organisation – <a href="https://www.who.int/csr/disease/smallpox/en/">smallpox</a> in 1980 and <a href="https://ourworldindata.org/how-rinderpest-was-eradicated">rinderpest</a> (a disease in cattle caused by the paramyxovirus) in 2011.</p>
<p>Polio is close to eradication with only <a href="http://polioeradication.org/polio-today/polio-now/this-week/">539 cases reported worldwide</a> in 2019. </p>
<p>Guinea worm disease is also close with <a href="https://www.who.int/dracunculiasis/epidemiology/en/">a total of just 19 human cases</a> from January to June 2019 across two African countries.</p>
<h2>What stage are we at with COVID-19?</h2>
<p>In Australia and New Zealand we currently have COVID-19 under control. </p>
<p>Importantly, in Australia, the effective reproduction number (R<sub>eff</sub>) is <a href="https://www.health.gov.au/sites/default/files/documents/2020/04/modelling-the-current-impact-of-covid-19-in-australia.pdf">close to zero</a>. Estimates of R<sub>eff</sub> come from mathematical modelling, which has not been published for New Zealand, but the R<sub>eff</sub> is likely to be close to zero in New Zealand too. </p>
<p>The R<sub>eff</sub> is the average number of people each infected person infects. So a R<sub>eff</sub> of 2 means on average, each person with COVID-19 infects two others. </p>
<p>If the R<sub>eff</sub> is greater than 1 the epidemic continues; if the R<sub>eff</sub> is equal to 1 it becomes endemic (that is, it grumbles along on a permanent basis); and if the R<sub>eff</sub> is lower than 1, the epidemic dies out. </p>
<p>So we could be on the way to elimination.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-sentinel-surveillance-and-how-might-it-help-in-the-fight-against-coronavirus-136845">What is sentinel surveillance and how might it help in the fight against coronavirus?</a>
</strong>
</em>
</p>
<hr>
<p>In both Australia and New Zealand we have found almost all of the imported cases, quarantined them, and undertaken contact tracing. Based on extensive community testing, there also appear to be very few community-acquired cases. </p>
<p>The next step in both countries will be sentinel surveillance, where random testing is carried out in selected groups. Hopefully in time these results will be able to show us COVID-19 has been eliminated.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/333304/original/file-20200507-49565-w0l8im.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/333304/original/file-20200507-49565-w0l8im.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/333304/original/file-20200507-49565-w0l8im.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/333304/original/file-20200507-49565-w0l8im.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/333304/original/file-20200507-49565-w0l8im.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/333304/original/file-20200507-49565-w0l8im.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/333304/original/file-20200507-49565-w0l8im.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">
<figcaption>
<span class="caption">The development of a vaccine can help control and eliminate a disease.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>It’s unlikely COVID-19 will ever be eradicated</h2>
<p>To be eradicated, a disease needs to be both preventable and treatable. At the moment, we neither have anything to prevent COVID-19 (such as a vaccine) nor any proven treatments (such as antivirals). </p>
<p>Even if a vaccine does become available, SARS-CoV-2 (the virus that causes COVID-19) <a href="https://www.sciencedirect.com/science/article/pii/S1567134820301829">easily mutates</a>. So we would be in a situation like we are with influenza, where we need annual vaccinations targeting the circulating strains. </p>
<p>The other factor making COVID-19 very difficult if not impossible to eradicate is the fact many infected people have few or no symptoms, and people could still be infectious <a href="https://www.health.gov.au/sites/default/files/documents/2020/03/coronavirus-covid-19-information-for-clinicians.pdf">even with no symptoms</a>. This makes case detection very difficult. </p>
<p>At least with smallpox, it was easy to see whether someone was infected, as their body was covered in pustules (fluid-containing swellings).</p>
<p>So while we may well be on the path to elimination in Australia and New Zealand, eradication is a different ball game.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-a-trans-tasman-travel-bubble-makes-a-lot-of-sense-for-australia-and-new-zealand-137878">Why a trans-Tasman travel bubble makes a lot of sense for Australia and New Zealand</a>
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</em>
</p>
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<img src="https://counter.theconversation.com/content/137991/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>Australia and New Zealand have well and truly ‘flattened the curve’, and there is now a real chance we could eliminate coronavirus in both countries. But what does elimination actually mean?Adrian Esterman, Professor of Biostatistics, University of South AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1088332019-01-14T13:15:47Z2019-01-14T13:15:47ZWhy does malaria recur? How pieces of the puzzle are slowly being filled in<figure><img src="https://images.theconversation.com/files/253242/original/file-20190110-32154-tqk3cy.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>Some people suffer from repeated attacks of malaria. These can occur weeks to months or longer after contracting the disease. The phenomenon is only too familiar to those who were bitten by mosquitoes carrying the type of malaria-causing organism known as <a href="http://dx.doi.org/10.1016/j.pt.2015.02.003"><em>Plasmodium vivax</em></a>. Whereas the malaria agent in Africa is primarily <em>Plasmodium falciparum</em>, <em>P. vivax</em> is the most widespread of the more than half a dozen malaria parasite species that infect humans globally.</p>
<p>An unresolved issue is why people experience recurrences of <em>P. vivax</em> malaria despite having received treatment for the disease. There’s also still not absolute clarity about where – in which organs and tissues – the parasites that are responsible for persisting infections hide. Because we don’t know this, we can’t determine how to kill them. Without filling in these blanks, we won’t be able to achieve the goal of eradicating malaria parasites everywhere in the world. </p>
<p>For the past four decades, I have intermittently been giving consideration to what makes malaria recur long after people have become infected by <em>P. vivax</em>, and have made some significant conceptual breakthroughs. These, combined with subsequent research by other scientists, have greatly enhanced our understanding of why malaria recurs. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/253245/original/file-20190110-43538-2nzaiu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/253245/original/file-20190110-43538-2nzaiu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/253245/original/file-20190110-43538-2nzaiu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/253245/original/file-20190110-43538-2nzaiu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/253245/original/file-20190110-43538-2nzaiu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/253245/original/file-20190110-43538-2nzaiu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/253245/original/file-20190110-43538-2nzaiu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An Anopheles mosquito.</span>
<span class="attribution"><span class="source">Ashley Burke</span></span>
</figcaption>
</figure>
<p>The most recent advance has been the ultimate acceptance of the theory I first propounded seven years ago. Namely, that the parasite multiplies – undetected – in more organs and <a href="http://dx.doi.org/10.1038/nrmicro3111">tissues</a> in the body than only the liver and bloodstream (which is conventional dogma). </p>
<p>One of the outcomes of this new conclusion is the increasing realisation that drugs might not eliminate malaria parasites with equal <a href="https://doi.org/10.1016/j.pt.2018.08.010">efficacy</a> in all of the parts of the body that they inhabit. This is a possible explanation (there are others too) for why malaria can recur despite treatment. </p>
<p>We still don’t have all the answers. But significant new insights are emerging which have important implications for the treatment of malaria, and eventually its eradication. </p>
<h2>The journey of discovery</h2>
<p>For some time now, it has been assumed that there’s only one source of malarial <a href="https://doi.org/10.1007/978-3-662-43978-4_3495">relapse</a>, namely, a <a href="http://dx.doi.org/10.1016/j.pt.2011.10.005">dormant</a> liver stage of the <em>P. vivax</em> parasite called the <a href="http://dx.doi.org/10.1007/s00436-010-2072-y">“hypnozoite”</a>. This term, which I <a href="http://dx.doi.org/10.1007/s10739-010-9239-3">coined</a> 41 years ago, is derived from the Greek words hypnos (sleep) and zoon (animal). Thus, a “sleeping animal”.</p>
<p>When a hypnozoite wakes up, it multiplies in the liver cell in which it’s living, resulting in the formation of a large number of progeny, called merozoites. After emerging from the liver cell, they invade red blood cells and reproduce inside them. When these cells burst, they release merozoites which then enter other red blood cells, in which the cycle is repeated.</p>
<p>It’s the ongoing proliferation of merozoite stage parasites in the bloodstream that leads to a recurrent bout of symptomatic illness. </p>
<p>Until now, liver cells – and especially blood vessels – have generally been considered to be the only habitats in humans where malaria parasites live and multiply.</p>
<p>But biomedical knowledge has changed. It’s now becoming <a href="https://www.researchgate.net/publication/328702818_Over-attribution_of_Plasmodium_vivax_malarial_recurrences_to_hypnozoite_activation">clearer</a> that recurrences are caused by not only merozoites inside blood vessels, but in fact by merozoites outside blood vessels too. </p>
<p>Seven years ago, I pointed out for the <a href="http://www.samj.org.za/index.php/samj/article/view/5220/3455">first time</a> (on the basis of some complicated initial <a href="http://dx.doi.org/10.1093/infdis/jis393">evidence</a>) that <em>P. vivax</em> recurrences can also be explained if there is a reservoir of merozoites outside the bloodstream.</p>
<p>The concept is simply that the non-bloodstream origin of <em>P. vivax</em> malarial recurrences can be both merozoites that occur outside blood vessels and hypnozoites in the liver (not hypnozoites only). </p>
<p>More recently, I figured out at the University of the Witwatersrand that <a href="https://doi.org/10.1017/S003118201800032X">bone marrow</a> probably serves as a merozoite reservoir for the <em>P. vivax</em> parasite. Other researchers had already suggested the <a href="https://doi.org/10.1017/S003118201800032X">possibility</a>. </p>
<p>Additionally, I have repeatedly rationalised that the same thing might apply to the <a href="https://doi.org/10.1016/j.pt.2018.08.010">spleen</a>, and perhaps other sites too. This was concluded by joining the dots (in other words, theoretically), partly through analysis of published literature, some of it relatively obscure.</p>
<h2>A paradigm shift</h2>
<p>This improved understanding is an important development and has implications for both the treatment of malaria and <a href="http://dx.doi.org/10.1016/j.pt.2017.03.002">elimination</a> of malaria parasites in human populations. This is because there are indications that a drug that kills merozoites in one site in the body will not necessarily kill all merozoites that occur elsewhere.</p>
<p>So not only might the patient not be cured, but parasites may periodically enter the circulating bloodstream and be sucked up by mosquitoes when they feed. This can result in further transmission of malaria when the infected mosquitoes bite other people. </p>
<p>But scientific dogma is often firmly entrenched. It took until last year for the idea that there is a dual origin of non-bloodstream parasites in <em>P. vivax</em> recurrences (both merozoites outside the bloodstream and hypnozoites) to gain <a href="https://doi.org/10.1016/j.pt.2018.08.010">acceptance</a>.</p>
<p>Disbelief – as well as some demonisation in knee-jerk reactions to my unconventional views – is progressively metamorphosing into agreement. This is happening mainly because of new research at Harvard University, the University of Glasgow, and elsewhere. Studies have yielded <a href="https://doi.org/10.1016/j.pt.2018.08.010">results</a> which can be adduced as additional support for my seven-year-old concept.</p>
<p>Consequently, a dramatic – and welcome – shift in attitude is taking place. Malariologists are <a href="https://doi.org/10.1016/j.pt.2018.08.010">beginning</a> to reiterate my concept and repeat supporting evidence for it that I had unearthed and included in bits and pieces in my publications in recent years, as well as presented at international <a href="https://www.researchgate.net/profile/Miles_Markus">conferences</a>.</p>
<h2>What’s next</h2>
<p>More research is being carried out to gain an even deeper understanding of the process of malarial recurrence. It involves studying parasites in cell culture, laboratory <a href="http://dx.doi.org/10.1016/j.pt.2016.02.006">mice</a>, and non-human primates, using sophisticated imaging and other cutting edge techniques. In association with this work, drug-related investigations are being undertaken in order to find out how best to treat patients who have <em>P. vivax</em> malaria.</p><img src="https://counter.theconversation.com/content/108833/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Miles B. Markus received relevant funding from the Bill & Melinda Gates Foundation; the British Council; the Royal Society (U.K.); the Wellcome Trust; and the South African Medical Research Council. A relevant conference travel grant was awarded by the National Research Foundation of South Africa.</span></em></p>Significant new insights are emerging for the treatment of malaria, and eventually its eradication.Miles B. Markus, Honorary Professorial Research Fellow, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/990232018-07-12T07:42:57Z2018-07-12T07:42:57ZEradicating cattle disease M. bovis in New Zealand may be costly, even impossible, but we must try<figure><img src="https://images.theconversation.com/files/227047/original/file-20180711-70045-1i945mt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A phased eradication of M. bovis means that an additional 126,000 cows will need to be culled, at an estimated cost of NZ$886 million.</span> <span class="attribution"><span class="source">from www.shutterstock.com</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>In May this year, the New Zealand government decided that it would attempt to <a href="https://www.beehive.govt.nz/release/plan-eradicate-mycoplasma-bovis">eradicate Mycoplasma bovis</a>, a bacterial disease that affects cattle.</p>
<p>A phased eradication means that an additional 126,000 livestock will need to be culled, at an estimated cost of NZ$886 million. </p>
<p>Here’s what we know, what we don’t know and what’s at stake. </p>
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Read more:
<a href="https://theconversation.com/australian-agricultures-biggest-threat-needs-a-global-approach-16512">Australian agriculture’s biggest threat needs a global approach</a>
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<h2>How do we know this is a new incursion?</h2>
<p>M. bovis causes mastitis and arthritis in adult cattle and pneumonia in calves. It is found around the world, but <a href="https://www.mpi.govt.nz/protection-and-response/mycoplasma-bovis/resources-for-mycoplasma-bovis/documents-guidance-and-fact-sheets/">New Zealand was one of the last disease-free countries</a> until the detection of infected cows on a dairy farm in July 2017. </p>
<p>We can’t be sure that M. bovis didn’t arrive in New Zealand before the current outbreak, but the Ministry of Primary Industries has tested for the disease over the years and not found it. This has involved checking animals with symptoms similar to those caused by M. bovis as well as large-scale test of bulk tank milk in 2007. </p>
<p>In addition, all countries with M. bovis – including Australia, where less than 4% of dairy herds are affected – have had outbreaks of <a href="https://www.dairyaustralia.com.au/news-listing/mycoplasma-bovis-in-australia?id=B38A06C53C0746FAA8D53272476658C7">untreatable mastitis and arthritis</a> due to M. bovis. No such outbreaks were recorded in New Zealand until July 2017. </p>
<p>In Australia, the disease was <a href="https://www.sciencedirect.com/science/article/pii/S0378113516304631?via%3Dihub%20https://www.sciencedirect.com/science/article/pii/S002203021730721X?via%3Dihub">first reported in the 1970s</a>, but it was not until 2006 that it was seen in the main dairying areas of New South Wales and Victoria where it caused outbreaks of mastitis. It is difficult to prove a negative and we certainly don’t have enough data to show it was definitively <em>not</em> in New Zealand before 2015. But the history of the disease in Australia shows that it can be detected even if it is rare. </p>
<p>Furthermore, the evidence so far from the investigation of the outbreak has been that all the infected farms can be traced back to cattle movements. If the disease had been here before, then tracing would likely have identified clusters of farms with no connections.</p>
<h2>Is eradication feasible?</h2>
<p>We do not currently know how the disease came into New Zealand. The only likely route, via imports of infected cattle, has been ruled out because live cattle imports ceased before 2015. In any case, live cattle imports have only come from Australia and the strain of bacteria in New Zealand is not the Australian one. Semen, embryos and illegal imports of veterinary products such as vaccines remain the most likely source, but all of these are very low risk. Although M. bovis can survive in these products, the chance of them being infected and that infection spreading to cattle is very low.</p>
<p>Without knowing where the disease came from, we cannot prevent it happening again. However, the risk of semen or embryos bringing in disease hasn’t changed in the last 20 years, so if it did indeed arrive via this route, it was simply bad luck. </p>
<p>So even if – after eradication – we did nothing to change the way semen, embryos or vaccine imports are regulated, it is possible that New Zealand would still remain free of M. bovis.</p>
<h2>How can we get rid of M. bovis?</h2>
<p>Authorities will use a systematic process of testing to identify infected herds. The biggest component will be testing the bulk tank milk of all dairy herds in the country. Tracing from infected herds will help to identify more infected herds and more traces. This is effectively a continuation of the current process with the aim of eliminating the disease.</p>
<p>The key problem with eradication is that currently the whole herd needs to be culled if one animal is infected because infection can only be detected at the herd level. This comes with significant cost and negative impact on affected farmers.</p>
<p>However, culling entire herds doesn’t necessarily influence the chances of a successful eradication process. The main issue is that we currently do not know exactly how many infected cattle or infected farms there are. It is going to take time to identify all the infected farms and it is possible that the number is much higher than the models suggest. This could make eradication impossible. </p>
<p>Tracing animal movements between farms is another key issue, and the lack of <a href="https://www.newsroom.co.nz/2018/05/15/109635/why-nait-failed-and-whats-being-done-to-fix-it">accurate recording</a> is hindering our response to the outbreak. For an eradication to be successful, farmers have to get better at keeping track of where animals are moved.</p>
<p>The decision to eradicate the disease is based on science, but it is not a scientific decision alone. Rightly, it is a political call, with the decisions being taken by the government with support from the industry. Eradication may prove to be impossible, but that does not mean we shouldn’t try. It just means that, unfortunately, the disease had spread far more widely than our current models suggest.</p><img src="https://counter.theconversation.com/content/99023/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Laven does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New Zealand has decided to attempt an eradication of the cattle disease Mycoplasma bovis, which means culling thousands of infected cattle.Richard Laven, Associate Professor Production Animal Health, Massey UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/774602017-05-23T20:23:19Z2017-05-23T20:23:19ZWidespread invasive species control is a risky business<figure><img src="https://images.theconversation.com/files/170482/original/file-20170523-8917-14t8me9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Partula snails were driven to extinction in the wild by introduced predators.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Pulmonata.jpg">Wikimedia Commons</a></span></figcaption></figure><p>In 1977, on the islands of French Polynesia, government authorities released a predatory snail. They hoped this introduction would effectively control another species of invasive snail, previously introduced to supply escargot. </p>
<p>Instead, by the early 1980s, scientists reported alarming declines of native snail populations. Within ten years, 48 native snail species (genus <em>Partula</em>) had been <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.2009.01245.x/full">driven to extinction in the wild</a>. </p>
<p>The extinction of the <em>Partula</em> is notorious partially because these snails were, before going extinct, the study subjects of the first test in nature of <a href="https://books.google.com.au/books/about/Studies_on_the_Variation_Distribution_an.html?id=LScwAAAAYAAJ&redir_esc=y">Darwin’s theory of evolution by natural selection</a>. </p>
<p>In the decades since, attempts to control and eradicate invasive species have become common, generally with <a href="http://www.pnas.org/content/113/15/4033.short">far better results</a>. </p>
<p>However, our paper, published today in <a href="https://www.nature.com/articles/s41559-017-0172">Nature Ecology and Evolution</a>, highlights the importance of scientific evidence and independent assessments when deciding whether to control or eradicate invasive species. </p>
<h2>From islands to continents</h2>
<p>Increasingly, large-scale invasive species control initiatives are being proposed worldwide. As early as 2018, a herpes virus will be released in Australia’s largest river system, targeting invasive <a href="https://www.nytimes.com/2016/06/15/world/what-in-the-world/australias-answer-to-invasive-carp-unprotected-group-sex-for-the-fish.html?_r=0">common carp</a>. As part of its <a href="http://www.environment.gov.au/biodiversity/threatened/publications/strategy-home">Threatened Species Strategy</a>, Australia is also planning to kill two million feral cats. </p>
<p>Across the Tasman Sea, New Zealand has made a bold commitment to remove <a href="https://academic.oup.com/bioscience/article/65/5/520/323246/Predator-Free-New-Zealand-Conservation-Country">three groups of invasive predators</a> entirely by 2050. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/170494/original/file-20170523-8876-1yyy3dn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/170494/original/file-20170523-8876-1yyy3dn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/170494/original/file-20170523-8876-1yyy3dn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=368&fit=crop&dpr=1 600w, https://images.theconversation.com/files/170494/original/file-20170523-8876-1yyy3dn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=368&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/170494/original/file-20170523-8876-1yyy3dn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=368&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/170494/original/file-20170523-8876-1yyy3dn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=462&fit=crop&dpr=1 754w, https://images.theconversation.com/files/170494/original/file-20170523-8876-1yyy3dn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=462&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/170494/original/file-20170523-8876-1yyy3dn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=462&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">New Zealand looks to eradicate three groups of invasive predators: rodents, mustelids, and the common brushtail possum.</span>
<span class="attribution"><span class="source">Geoff Whalan/Flickr</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>It’s not just Australians and Kiwis making ambitious invasive species control proposals: <a href="http://www.nature.com/news/invasive-species-control-bounty-hunters-1.15916">bounties</a> are being paid to catch invasive fish in the United States. The European Union has <a href="http://ec.europa.eu/environment/pdf/13_07_2016_news_en.pdf">blacklisted</a> 37 species of plants and animals within 4 million square kilometres, many of which are well-established and will be targeted by control (not preventative) measures.</p>
<p>Meanwhile, <a href="http://www.pnas.org/content/112/34/10565.full">new gene editing technology</a> has made the continental-scale eradication of invasive species a real possibility, for example by implementing gene drives that <a href="https://theconversation.com/gene-drives-may-cause-a-revolution-but-safeguards-and-public-engagement-are-needed-77012">reduce breeding success</a>. If you haven’t heard of it, <a href="https://en.wikipedia.org/wiki/CRISPR">CRISPR</a> is a startling new biotechnology that makes genetic modification of plants and animals much easier. It offers new potential solutions to some of the world’s worst environmental, agricultural and human health problems.</p>
<p>These schemes will be implemented across large and complex social-ecological systems, and some options – like releasing a virus or genetically engineered species – may be irreversible. </p>
<h2>Managing risk</h2>
<p>While these projects may yield great benefits, we must be aware of the potential risk of unexpected and undesirable outcomes.</p>
<p>A prime example is the project to remove invasive carp from a million square kilometres of Australia’s rivers. Some scientists have <a href="https://www.nature.com/articles/s41559-017-0087">expressed concern</a> about the potential for the virus to jump species, and the effects of having hundreds of tonnes of dead fish fouling waterways and sapping oxygen from the water. The CSIRO and those planning the release of the virus suggest it is safe and effective.</p>
<p>Despite extensive media reporting giving the impression that the plan is approved to go ahead, the <a href="http://frdc.com.au/carp/Pages/default.aspx">National Carp Control Plan</a> has yet to publish a risk assessment, and is planning to deliver a report in 2018.</p>
<p>Removing well-established invasive species can create unforeseen consequences. These species can play <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.2010.01646.x/full">significant roles</a> in food webs, provide shelter for native animals, support ecosystem services, and their sudden death can disrupt ecological processes that are important to native species.</p>
<p>For example, a large amount of time and effort was spent in removing the non-native tamarix (or “salt cedar”) in the southwestern United States, because of the belief it was harming the water table.</p>
<p>Yet, subsequent <a href="https://books.google.com.au/books?hl=en&lr=&id=e3V9I44S2toC&oi=fnd&pg=PP1&dq=tamarisk+and+fly+catcher&ots=AuysM3w-s7&sig=4bgn9CTwqhWDXd5XotEYC0YQE6o#v=onepage&q=tamarisk%20and%20fly%20catcher&f=false">research</a> has indicated that the negative effects of tamarix have been exaggerated. In some areas, the plant is actually used by large numbers of endangered flycatchers to nest and fledge their young. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/170478/original/file-20170523-8883-1cjatd8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/170478/original/file-20170523-8883-1cjatd8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/170478/original/file-20170523-8883-1cjatd8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/170478/original/file-20170523-8883-1cjatd8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/170478/original/file-20170523-8883-1cjatd8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/170478/original/file-20170523-8883-1cjatd8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/170478/original/file-20170523-8883-1cjatd8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A corn bunting perches on a blooming tamarix.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/corn-bunting-emberiza-calandra-on-blooming-184173191?src=93OTqNrvy0Nco4AFiJ8cnQ-1-8">Georgios Alexandris/shutterstock</a></span>
</figcaption>
</figure>
<h2>A science-based solution</h2>
<p>In our <a href="https://www.nature.com/articles/s41559-017-0172">paper</a>, we highlight a series of considerations that should be addressed before plunging into large-scale invasive species control. </p>
<p>Fundamentally, there must be a demonstrable ecological and social benefit from control or eradication, above and beyond the purely ideological. At first this might seem facile, but invasive species control initiatives are often highly politicised, with science taking a back seat. Given scarce funding for conservation, it is crucial that resources are not squandered on programmes that may not deliver - or could cause environmental damage. </p>
<p>We must avoid assuming that attempting to control invasive species will, by default, solve our environmental problems. This means addressing the full range of human pressures which negatively affect biodiversity. We must also consider how removing an influential invasive species could benefit other invasive species, harm native species through increased predation and competition, or alter ecological processes or habitat. </p>
<p>Comprehensive risk-benefit assessment of invasive species control programs allow decision-makers to proactively avoid, manage or accept these risks. </p>
<p>For example, tonnes of decomposing carp post-virus may cause short-term water quality issues, or the death of native species. Ultimately, however, these risks could be acceptable <em>if</em> the virus is effective, and allows native species a window of opportunity to recover.</p>
<p>Large-scale invasive species control demands careful investigation of the risks and rewards. We hope our paper can provide policy-makers with better guidelines for science-based decision-making.</p><img src="https://counter.theconversation.com/content/77460/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>R. Keller Kopf has applied for funding from the Fisheries Research and Development Corporation to assess the: Ecological, Social and Socio-Economic Risks of Releasing Koi Herpes Virus to Control Common Carp in Australia.</span></em></p><p class="fine-print"><em><span>Dale Nimmo receives funding from the Australian Research Council, the Australian Academy of Science, the Hermon Slade Foundation, the Department of Parks and Wildlife, and the Department of Land, Water and Planning. </span></em></p><p class="fine-print"><em><span>Paul Humphries receives funding from the MDBA Environmental Water Knowledge and Research Program and has received funding from the MDBA Native Fish Strategy. He is a collaborator on an application for funding from the Fisheries Research and Development Corporation in relation to the Koi Herpes Virus to Control Common Carp in Australia.. </span></em></p>Before we decide to eradicate or control an invasive species, like carp, we need plenty of scientific evidence and independent assessments first.R. Keller Kopf, Research fellow, Charles Sturt UniversityDale Nimmo, ARC DECRA Fellow, Charles Sturt UniversityPaul Humphries, Senior lecturer in Ecology, Charles Sturt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/494872015-11-12T11:00:48Z2015-11-12T11:00:48ZCould a smartphone app help stop the next polio outbreak in Pakistan?<p>Between 1988 and 2013, the number of cases of polio worldwide plummeted from 350,000 <a href="http://www.vox.com/2014/5/7/5688112/why-polio-is-on-the-rise-again">to 406</a>. The number of countries in which the disease was endemic also went down, from 125 to three. The world seemed on the verge of eradicating the disease once and for all.</p>
<p>In 2014, polio surged again to <a href="http://www.who.int/features/qa/07/en">359 cases</a>, with <a href="http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6419a5.htm">85% of the new cases</a> appearing in Pakistan. According to the World Health Organization, people with the disease were crossing the border into Afghanistan, and strains of the virus that originated in Pakistan were found in Egyptian sewers.</p>
<p>Neighboring India <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3734678/">eliminated the disease in 2011</a>, after switching to a more effective vaccine and ramping up vaccination efforts. Compared to Pakistan, India clearly had greater capacity to respond, and it didn’t face as much political unrest or a border with Afghanistan. Still, many other countries with weak central governments had eliminated the disease. So why not Pakistan?</p>
<p>The reason Pakistan was having so much trouble didn’t come down to having enough doses of the vaccines or health workers to administer them – the country did. A key problem was that information about who was getting vaccinated wasn’t getting collected, and that the incentives health workers got didn’t actually motivate them to perform more vaccinations.</p>
<p>Our group of researchers wanted to find a way of making sure that more detailed information about vaccinations was collected and to develop better incentives for health workers. The solution we found (and which we detail in a <a href="https://www.dropbox.com/s/d6efb1uws8emmam/ACJKS_polio_preliminary.pdf?dl=0">draft paper</a>) is cheap and portable: smartphones.</p>
<h2>What happened in Pakistan?</h2>
<p>Because Pakistan lacks data on which citizens needed to be vaccinated, the government aims to achieve complete vaccination coverage by <a href="https://www.dropbox.com/s/d6efb1uws8emmam/ACJKS_polio_preliminary.pdf?dl=0">going door-by-door</a>. To do this, the government assigns four or five roving teams of health workers to vaccinate each neighborhood. These drives happen about once a month and usually last for at least two days.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/100987/original/image-20151105-16277-euh0ct.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/100987/original/image-20151105-16277-euh0ct.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=882&fit=crop&dpr=1 600w, https://images.theconversation.com/files/100987/original/image-20151105-16277-euh0ct.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=882&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/100987/original/image-20151105-16277-euh0ct.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=882&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/100987/original/image-20151105-16277-euh0ct.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1109&fit=crop&dpr=1 754w, https://images.theconversation.com/files/100987/original/image-20151105-16277-euh0ct.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1109&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/100987/original/image-20151105-16277-euh0ct.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1109&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An example of a map used by health workers for vaccination campaigns.</span>
<span class="attribution"><span class="source">Michael Callen</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Health workers on these vaccination drives don’t face an easy task, especially in a city of six million like Lahore. </p>
<p>Information about who has been vaccinated or where teams have gone isn’t centralized. Rather, teams use paper maps and forms to figure out where to go and to record their efforts. To show what houses have been visited, health workers use chalk to write on the walls of houses. The only information recorded centrally is a team’s daily total number of vaccinations.</p>
<p>The government paid workers for the door-to-door drive with one-size-fits-all incentives – 100 rupees (about US$1) per day regardless of who or how many they vaccinated. The incentives, in other words, weren’t based on performance. </p>
<p>Combine all of these factors, and the result was that some children were immunized several times and others, in small pockets isolated by geography or violence, were not vaccinated at all.</p>
<h2>Better incentives can help, but they need the right data to work</h2>
<p>In rich and poor countries, pay-for-performance systems that use incentives have proven particularly effective in health care. </p>
<p>In a pay-for-perfomance system, a worker’s pay is higher when they perform better. Implementing performance pay necessarily requires high-quality, detailed data on performance, which is hard or impossible to use when it is recorded on paper or chalked on the sides of houses. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/100989/original/image-20151105-16239-kjj20o.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/100989/original/image-20151105-16239-kjj20o.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=443&fit=crop&dpr=1 600w, https://images.theconversation.com/files/100989/original/image-20151105-16239-kjj20o.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=443&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/100989/original/image-20151105-16239-kjj20o.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=443&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/100989/original/image-20151105-16239-kjj20o.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=557&fit=crop&dpr=1 754w, https://images.theconversation.com/files/100989/original/image-20151105-16239-kjj20o.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=557&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/100989/original/image-20151105-16239-kjj20o.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=557&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An example of forms used by health workers to track vaccinations.</span>
<span class="attribution"><span class="source">Michael Callen</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>In a pilot project funded by the UK Department for International Development, our group has been working with Lahore’s municipal government to <a href="https://www.dropbox.com/s/u06ay4esj8sugyf/ACJKS_Polio_NEUDC.pdf?dl=0">develop a tool</a> to help track information better and to find out what incentives provide the best motivation for health workers.</p>
<p>We distributed <a href="http://www.nber.org/papers/w21180.pdf">cheap smartphones</a> to the health workers so they could send geo-coded information about their activities to a centralized dashboard. After they visited each home, they would send back data about how many children they had vaccinated, the time that the vaccination visit occurred, and the address it occurred at as coded by GPS location. </p>
<p>We also changed the incentive for workers. Instead of a bonus that workers got regardless of how many vaccinations they did or households they visited, we introduced an incentive system that offered a bigger bonus for better performance.</p>
<p>Each worker needed to visit 300 households in the first two days of the campaign, but they could set a goal in advance for how many houses they wanted to visit on each of these days. This allowed workers some flexibility over when they performed their vaccinations. The app also recorded each time they visited a household to perform a vaccination in real time. </p>
<p>Meeting the target meant a health worker would get her bonus. Meanwhile, data about actual vaccinations were aggregated, visualized and sent to an online portal for policymakers to use.</p>
<p>By recording personal goals for first two days of the campaign, workers indicated how much they preferred to delay visits from the first day to the second day. Some workers set high targets for the first day, and other workers pushed more vaccinations off to the second day. We were able to use this information to design incentives that were used in the second round of the campaign. </p>
<p>For instance, workers that tended to delay vaccinations to the second day got an incentive scheme where vaccinations performed on the second day didn’t count as much toward their goal of 300 as vaccinations performed on the first day. This helped provide more incentive for these workers to do more on the first day.</p>
<h2>Better data mean better incentives, which means more vaccinations</h2>
<p>We piloted the system among 505 workers, divided into different treatments and control groups in a randomized trial. Our preliminary findings, based on data from the mobile phones, shows that the bonus did improve performance: incentivized workers completed 15% to 17% more vaccinations than workers who are just being monitored and not positively rewarded. </p>
<p>The individually tailored incentive structure achieved its intended goal of causing workers to even out their effort over the two days. </p>
<p>Preliminary results further suggest that individually tailoring can also be used to increase the total number of vaccinations, though this would require a different set of incentives than those we evaluated. And in the few cases where parents didn’t allow their children to be vaccinated, the online dashboard allowed policymakers to identify those households for follow-up. </p>
<p>In upcoming vaccination drives, we will use these data to understand why certain pockets remain unvaccinated, and formulate a pay gradient that will push workers to fill in those gaps. </p>
<h2>Mapping individual performance</h2>
<p>Obviously people are individuals, and workers respond to incentives in very different ways. We can map out individual decision-making tendencies to target incentives – even exploit those differences for the public’s gain.</p>
<p>Our results suggest that this system can bridge the pay-for-performance information gap very quickly. Indeed, Pakistan’s government is scaling up the technology under the banner of Punjab Information Technology Board (PITB) and aims to implement the program well beyond Lahore. </p>
<p>These tools are simple – just smartphones and apps – and could be used in any developing country to collect better data and target workers efforts more effectively.</p><img src="https://counter.theconversation.com/content/49487/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Callen 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>Researchers are piloting a smartphone app to collect better information about who is getting vaccinated and to design better incentives for health workers on vaccination drives.Michael Callen, Assistant Professor of Public Policy, Harvard UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/268462014-05-19T05:09:58Z2014-05-19T05:09:58ZGuinea-worm disease could be next on the list of eradicated afflictions<figure><img src="https://images.theconversation.com/files/48739/original/vb4w3gp4-1400250849.jpg?ixlib=rb-1.1.0&rect=43%2C83%2C1378%2C910&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ouch.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/medicalmuseum/4951113771/">medicalmuseum</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>In 1986 Guinea-worm disease infected 3.5m people. Simple interventions have since ensured that <a href="http://www.who.int/mediacentre/factsheets/fs359/en/">in 2013</a> only 148 cases were recorded. With a final push, this could be the third disease to be eradicated from the planet after smallpox, which needed a <a href="http://www.who.int/features/2010/smallpox/en/">worldwide vaccination campaign</a> led by the World Health Organisation in the 1970s, and Rinderpest, which required a similar effort. </p>
<p>Guinea-worm disease has been around for a long time. The bible mentions this disease as the “plague of fiery serpents”. Although it doesn’t cause death, it is <a href="https://theconversation.com/six-human-parasites-you-definitely-dont-want-to-host-17332">very painful</a>. The disease is caused by the Guinea worm, a long, thin worm that lives inside your leg or arm. </p>
<p>That sounds bad enough, but it gets worse when the female worm starts to have babies. A painful boil erupts where the female’s body comes near the surface of the skin and out come hundreds of baby worms. When this happens, the traditional treatment is to catch the end of the female worm protruding from the boil and wind it on a matchstick, a little more each day until it is all out. This is important as any left inside will fester.</p>
<p>But this disease is very easy to avoid if you know how. To survive, the baby worms need to get into water – and they have this opportunity when you bathe your leg in water to ease the throbbing, burning pain. If this water is a pond or pool, the tiny worms will get eaten by little bugs. This is not a problem unless the pool is also the main source of drinking water – sooner or later the little bug, along with its cargo of guinea worms, will end up being drunk by someone and that is when the infection starts again. The baby worm soon grows into an adult, finds a mate and raises a family.</p>
<p>To break the cycle, people need to avoid drinking water with bugs. A proper supply of piped water is ideal, but sadly not yet available to everyone in the world. Next best is to filter the water – a simple, low-tech and cheap method within reach of the poorest people.</p>
<p>The other important thing is to stop people who are infected from releasing the baby worms into the supply of drinking water. These are the two simple measures that have been implemented over the past 20 years as part of the <a href="http://www.cartercenter.org/health/guinea_worm/index.html">Guinea worm eradication programme</a>, led by fromer US president Jimmy Carter.</p>
<p>At the heart of the program is education, to provide local communities in rural Africa with the knowledge and tools to avoid this awful scourge. A special net cloth suitable for filtering the drinking water is also provided. The source of the drinking water can be treated with a chemical, which destroys not only the bugs infected with Guinea worm, but also other harmful pests such as mosquitoes that breed in stagnant water. </p>
<p>The other arm of the program is to prevent drinking water being contaminated by infected people in the first place. This is achieved by organising villagers’ tasks so that people infected with mature worms are kept away from all water sources until they are clear of the worm. They do this by ensuring that infected people don’t collect water, instead a healthy neighbour does it for them.</p>
<p>Through these simple measures, Guinea-worm disease is well on the way to eradication, maybe by the end of 2015. And this will have been achieved by low-tech solutions and community action, rather than expensive drugs or vaccines.</p><img src="https://counter.theconversation.com/content/26846/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wendy Gibson 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>In 1986 Guinea-worm disease infected 3.5m people. Simple interventions have since ensured that in 2013 only 148 cases were recorded. With a final push, this could be the third disease to be eradicated…Wendy Gibson, Professor of Protozoology, University of BristolLicensed as Creative Commons – attribution, no derivatives.