tag:theconversation.com,2011:/africa/topics/hendra-virus-979/articlesHendra virus – The Conversation2022-11-16T19:02:51Ztag:theconversation.com,2011:article/1946342022-11-16T19:02:51Z2022-11-16T19:02:51ZTo stop new viruses jumping across to humans, we must protect and restore bat habitat. Here’s why<figure><img src="https://images.theconversation.com/files/495554/original/file-20221116-21-drd21f.jpg?ixlib=rb-1.1.0&rect=40%2C28%2C3803%2C2224&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Grey headed flying fox (Pteropus poliocephalus)</span> <span class="attribution"><span class="source">Vivien Jones</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Bats have lived with coronaviruses for millennia. Details are still hazy about how one of these viruses evolved into SARS-CoV-2, which causes COVID in humans. Did it go directly from bats to humans or via another animal species? When? And why? If we can’t answer these questions for this now-infamous virus, we have little hope of preventing the next pandemic.</p>
<p>Some bat species are <a href="https://theconversation.com/bats-are-hosts-to-a-range-of-viruses-but-dont-get-sick-why-139056">hosts for other viruses</a> lethal to humans, from rabies to <a href="https://www.who.int/news-room/fact-sheets/detail/nipah-virus">Nipah</a> to <a href="https://www.who.int/health-topics/hendra-virus-disease#tab=tab_1">Hendra</a>. But their supercharged immune systems allow them to co-exist with these viruses without appearing sick. </p>
<p>So what can we do to prevent these viruses emerging in the first place? We found one surprisingly simple answer in our <a href="https://www.nature.com/articles/s41586-022-05506-2">new research</a> on flying foxes in Australia: protect and restore native bat habitat to boost natural protection.</p>
<p>When we destroy native forests, we force nectar-eating flying foxes into survival mode. They shift from primarily nomadic animals following eucalypt flowering and forming large roosts to less mobile animals living in a large number of small roosts near agricultural land where they may come in contact with horses. </p>
<p>Hendra virus is carried by bats and can spill over to horses. It doesn’t often spread from horses to humans, but when it does, it’s <a href="https://www.health.nsw.gov.au/Infectious/controlguideline/Pages/hendra-case-summary.aspx">extremely dangerous</a>. Two-thirds of Hendra cases in horses have occurred in heavily cleared areas of northern New South Wales and south-east Queensland. That’s not a coincidence. </p>
<p>Now we know how habitat destruction and spillover are linked, we can act. Protecting the eucalyptus species flying foxes rely on will reduce the risk of the virus spreading to horses and then humans. The data we gathered also makes it possible to predict times of heightened Hendra virus risk – up to two years in advance. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/495553/original/file-20221116-17-txxcra.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="grey headed flying fox in flight" src="https://images.theconversation.com/files/495553/original/file-20221116-17-txxcra.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/495553/original/file-20221116-17-txxcra.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/495553/original/file-20221116-17-txxcra.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/495553/original/file-20221116-17-txxcra.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/495553/original/file-20221116-17-txxcra.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/495553/original/file-20221116-17-txxcra.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/495553/original/file-20221116-17-txxcra.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">Grey headed flying foxes prefer to roost in huge groups, feeding on eucalypt nectar. But if there are no eucalypts, they look for food in rural and suburban areas.</span>
<span class="attribution"><span class="source">Vivien Jones</span>, <span class="license">Author provided</span></span>
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<h2>What did we find out?</h2>
<p>Many Australians are fond of flying foxes. Our largest flying mammal is often seen framed against summer night skies in cities. </p>
<p>These nectar-loving bats play a vital ecosystem role in pollinating Australia’s native trees. (Pollination in Australia isn’t limited to bees – flies, moths, birds and bats do it as well). Over winter, they rely on nectar from a few tree species such as forest red gums (<em>Eucalyptus tereticornis</em>) found mostly in southeast Queensland and northeast NSW. Unfortunately, most of this habitat has been cleared for agriculture or towns. </p>
<p>Flying foxes are typically nomadic, flying vast distances across the landscape. When eucalypts burst into flower in specific areas, these bats will descend on the abundant food and congregate in lively roosts, often over 100,000 strong. </p>
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Read more:
<a href="https://theconversation.com/its-wrong-to-blame-bats-for-the-coronavirus-epidemic-134300">It's wrong to blame bats for the coronavirus epidemic</a>
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<p>But Australia is a harsh land. During the severe droughts brought by El Niño, eucalyptus trees may stop producing nectar. To survive, flying foxes must change their behaviour. Gone are the large roosts. Instead, bats spread in many directions, seeking other food sources, like introduced fruits. This response typically only lasts a few weeks. When eucalypt flowering resumes, the bats come back to again feed in native forests. </p>
<p>But what happens if there are not enough forests to come back to? </p>
<p>Between 1996 and 2020, we found large winter roosts of nomadic bats in southeast Queensland became increasingly rare. Instead, flying foxes were forming small roosts in rural areas they would normally have ignored and feeding on introduced plants like privet, camphor laurel and citrus fruit. This has brought them into closer contact with horses.</p>
<p>In related research <a href="https://doi.org/10.1111/ele.14007">published last month</a>, we found the smaller roosts forming in these rural areas also had higher detection rates of Hendra virus – especially in winters after a climate-driven nectar shortage. </p>
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<a href="https://images.theconversation.com/files/495507/original/file-20221115-10481-529eus.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="flying fox" src="https://images.theconversation.com/files/495507/original/file-20221115-10481-529eus.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/495507/original/file-20221115-10481-529eus.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=408&fit=crop&dpr=1 600w, https://images.theconversation.com/files/495507/original/file-20221115-10481-529eus.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=408&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/495507/original/file-20221115-10481-529eus.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=408&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/495507/original/file-20221115-10481-529eus.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=513&fit=crop&dpr=1 754w, https://images.theconversation.com/files/495507/original/file-20221115-10481-529eus.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=513&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/495507/original/file-20221115-10481-529eus.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=513&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Flying foxes are social, intelligent – and play a key role in pollinating native trees.</span>
<span class="attribution"><span class="source">Vivien Jones</span>, <span class="license">Author provided</span></span>
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<h2>An early warning system for Hendra virus</h2>
<p>Our models confirmed strong El Niño events caused nectar shortages for flying foxes, splintering their large nomadic populations into many small populations in urban and agricultural areas. </p>
<p>Importantly, the models showed a strong link between food shortages and clusters of Hendra virus spillovers from these new roosts in the following year. </p>
<p>This means by tracking drought conditions and food shortages for flying foxes, we can get crucial early warning of riskier times for Hendra virus – up to two years in advance. </p>
<p>Biosecurity, veterinary health and human health authorities could use this information to warn horse owners of the risk. Horse owners can then ensure their horses are protected with the vaccine. </p>
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<a href="https://images.theconversation.com/files/495559/original/file-20221116-20-hv7kdm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Flying fox asleep" src="https://images.theconversation.com/files/495559/original/file-20221116-20-hv7kdm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/495559/original/file-20221116-20-hv7kdm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/495559/original/file-20221116-20-hv7kdm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/495559/original/file-20221116-20-hv7kdm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/495559/original/file-20221116-20-hv7kdm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/495559/original/file-20221116-20-hv7kdm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/495559/original/file-20221116-20-hv7kdm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&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">Habitat destruction makes winter flowering and nectar production unreliable, and means congregations of flying foxes in large roosts are increasingly rare.</span>
<span class="attribution"><span class="source">Pat Jones</span>, <span class="license">Author provided</span></span>
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<h2>How can we stop the virus jumping species?</h2>
<p>Conservationists have long pointed out human health depends on a healthy environment. This is a very clear example. We found Hendra virus never jumped from flying foxes to horses when there was abundant winter nectar. </p>
<p>Protecting and restoring bat habitat and replanting key tree species well away from horse paddocks will boost bat health – and keep us safer. </p>
<p>Flying foxes leave roosts in cities or rural areas when there are abundant flowering gums elsewhere. It doesn’t take too long – trees planted today could start drawing bats within a decade. </p>
<p>SARS-CoV-2 won’t be the last bat virus to jump species and upend the world. As experts plan ways to better respond to next pandemic and work on <a href="https://www.nature.com/articles/s41541-021-00284-w">human vaccines</a> built on the <a href="https://www.csiro.au/en/research/animals/livestock/hendra">equine Hendra vaccines</a>, we can help too. </p>
<p>How? By restoring and protecting the natural barriers which for so long kept us safe from bat-borne viruses. It is far better to prevent viruses from spilling over in the first place than to scramble to stop a possible pandemic once it’s begun. </p>
<p>Planting trees can help stop dangerous new viruses reaching us. It really is as simple as that. </p>
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Read more:
<a href="https://theconversation.com/bats-are-hosts-to-a-range-of-viruses-but-dont-get-sick-why-139056">Bats are hosts to a range of viruses but don't get sick – why?</a>
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<img src="https://counter.theconversation.com/content/194634/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alison Peel has received funding from Australian Research Council (DE190100710), the US National Science Foundation (DEB1716698) and the US Defense Advanced Research Projects Agency (D18AC00031). She is a member of the Wildlife Health Australia Bat Health Focus Group and the Human Animal Spillover and Emerging Diseases Scanning (HASEDS) working group.</span></em></p><p class="fine-print"><em><span>Peggy Eby has received funding from the US National Science Foundation (DEB1716698) and the US Defense Advanced Research Projects Agency (D18AC00031). </span></em></p><p class="fine-print"><em><span>Raina Plowright has received funding from the US National Science Foundation (DEB1716698), the US Defense Advanced Research Projects Agency (D18AC00031) and the U.S. National Institute of Food and Agriculture (1015891)</span></em></p>Bats host many viruses dangerous to humans. But it’s only when their habitats are destroyed that we’re at risk.Alison Peel, Senior Research Fellow in Wildlife Disease Ecology, Griffith UniversityPeggy Eby, Adjunct Senior Lecturer, Centre for Ecosystem Science, UNSW SydneyRaina Plowright, Professor, Cornell UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1885772022-08-11T03:25:21Z2022-08-11T03:25:21ZWhat is this new Langya virus? Do we need to be worried?<figure><img src="https://images.theconversation.com/files/478856/original/file-20220812-14242-rlavkp.jpg?ixlib=rb-1.1.0&rect=3%2C12%2C2114%2C1397&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">People could have caught the virus from wild shrews.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com.au/photos/shrew-erhard-nerger?assettype=image&license=rf&alloweduse=availableforalluses&agreements=pa%3A136296&family=creative&phrase=shrew%20Erhard%20Nerger&sort=best">Erhard Nerger/Getty Images</a></span></figcaption></figure><p>A new virus, Langya henipavirus, is <a href="https://www.nejm.org/doi/full/10.1056/NEJMc2202705?query=featured_home">suspected</a> to have caused infections in 35 people in China’s Shandong and Henan provinces over roughly a two-year period to 2021.</p>
<p>It’s related to Hendra and Nipah viruses, which cause disease in humans. However, there’s much we don’t know about the new virus – known as LayV for short – including whether it spreads from human to human.</p>
<p>Here’s what we know so far.</p>
<h2>How sick are people getting?</h2>
<p>Researchers in China first detected this new virus as part of routine surveillance in people with a fever who had reported recent contact with animals. Once the virus was identified, the researchers looked for the virus in other people. </p>
<p>Symptoms reported appeared to be mostly mild – fever, fatigue, cough, loss of appetite, muscle aches, nausea and headache – although we don’t know how long the patients were unwell. </p>
<p>A smaller proportion had potentially more serious complications, including pneumonia, and abnormalities in liver and kidney function. However, the severity of these abnormalities, the need for hospitalisation, and whether any cases were fatal were not reported.</p>
<h2>Where did this virus come from?</h2>
<p>The authors also investigated whether domestic or wild animals may have been the source of the virus. Although they found a small number of goats and dogs that may have been infected with the virus in the past, there was more direct evidence a significant proportion of wild shrews were harbouring the virus. </p>
<p>This suggests humans may have caught the virus from wild shrews.</p>
<h2>Does this virus actually cause this disease?</h2>
<p>The researchers used a modern technique known as <a href="https://www.nature.com/articles/s41576-019-0113-7">metagenomic analysis</a> to find this new virus. Researchers sequence all genetic material then discard the “known” sequences (for example, human DNA) to look for “unknown” sequences that might represent a new virus.</p>
<p>This raises the question about how scientists can tell whether a particular virus causes the disease. </p>
<p>We have traditionally used “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3775492/">Koch’s postulates</a>” to determine whether a particular micro-organism causes disease:</p>
<ul>
<li><p>it must be found in people with the disease and not in well people</p></li>
<li><p>it must be able to be isolated from people with the disease</p></li>
<li><p>the isolate from people with the disease must cause the disease if given to a healthy person (or animal)</p></li>
<li><p>it must be able to be re-isolated from the healthy person after they become ill.</p></li>
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<p>The authors acknowledge this new virus doesn’t yet meet these criteria, and the relevance of these criteria in the modern era has been <a href="https://journals.asm.org/doi/10.1128/CMR.9.1.18">questioned</a>.</p>
<p>However, the authors say they didn’t find any other cause of the illness in 26 people, there was evidence 14 people’s immune systems had responded to the virus, and people who were more unwell had more virus.</p>
<h2>What can we learn from related viruses?</h2>
<p>This new virus appears to be a close cousin of two other viruses that are significant in humans: Nipah virus and Hendra virus. This family of viruses was the inspiration for the fictional MEV-1 virus in the film <a href="https://www.reuters.com/article/idUS57323549020110913">Contagion</a>.</p>
<p>Hendra virus was first <a href="https://onlinelibrary.wiley.com/doi/abs/10.5694/j.1326-5377.1995.tb126050.x">reported</a> in Queensland in 1994, when it caused the deaths of 14 horses and the trainer <a href="https://www.smh.com.au/sport/racing/vics-bravery-no-match-for-bat-virus-20110827-1jfep.html">Vic Rail</a>. </p>
<p>Many outbreaks in horses have been reported in Queensland and northern New South Wales since, and are generally thought to be due to “spillover” infections from flying foxes. </p>
<p>In total, seven human cases of Hendra virus have been <a href="https://www.outbreak.gov.au/for-vets-and-scientists/hendra-virus">reported</a> in Australia (mostly veterinarians working with sick horses), including four deaths.</p>
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Read more:
<a href="https://theconversation.com/explainer-why-is-hendra-virus-so-dangerous-2083">Explainer: Why is Hendra virus so dangerous?</a>
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<p>Nipah virus is more <a href="https://www.who.int/news-room/fact-sheets/detail/nipah-virus">significant</a> globally, with outbreaks frequently reported in Bangladesh. </p>
<p>The severity of infection can range from very mild to fatal encephalitis (inflammation of the brain). </p>
<p>The first outbreak in Malaysia and Singapore was <a href="https://pubmed.ncbi.nlm.nih.gov/10781618/">reported</a> in people who had close contact with pigs. However, it is <a href="https://www.cdc.gov/vhf/nipah/transmission/index.html">thought</a> more recent outbreaks have been due to food contaminated with the urine or saliva of infected bats. </p>
<p>Significantly, Nipah virus appears to be <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6547369/">transmitted</a> from person to person, mostly among household contacts.</p>
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Read more:
<a href="https://theconversation.com/humans-are-to-blame-for-the-rise-in-dangerous-viral-infections-94747">Humans are to blame for the rise in dangerous viral infections</a>
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<h2>What do we need to find out next?</h2>
<p>Little is known about this new virus, and the currently reported cases are likely to be the tip of the iceberg. </p>
<p>At this stage, there is no indication the virus can spread from human to human. </p>
<p>Further work is required to determine how severe the infection can be, how it spreads, and how widespread it might be in China and the region. </p>
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Read more:
<a href="https://theconversation.com/the-next-global-health-pandemic-could-easily-erupt-in-your-backyard-138861">The next global health pandemic could easily erupt in your backyard</a>
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<p><em>Update: this article has been updated to say the cases were detected over roughly a two-year period to 2021. The main image now shows the type of shrew thought to be the animal reservoir of the Langya virus.</em></p><img src="https://counter.theconversation.com/content/188577/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Allen Cheng receives funding from the National Health and Medical Research Council.</span></em></p>The virus is related to Hendra and Nipah viruses. But we don’t know whether it spreads from human to human.Allen Cheng, Professor in Infectious Diseases Epidemiology, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1684732021-09-23T20:05:52Z2021-09-23T20:05:52ZNew preliminary evidence suggests coronavirus jumped from animals to humans multiple times<p>The origin of the SARS-CoV-2 virus, which has caused the COVID-19 pandemic, has been hotly debated.</p>
<p>This debate has caused substantial difficulties in the Australia-China relationship, with a call by Foreign Minister <a href="https://www.abc.net.au/news/2020-04-19/payne-calls-for-inquiry-china-handling-of-coronavirus-covid-19/12162968">Marise Payne for another inquiry into its origin</a> being considered by China as a hostile act.</p>
<p>What’s not in doubt is the <a href="https://www.nature.com/articles/s41591-020-0820-9">closest relatives of the virus are found in bats</a>. How, where and when the virus spilled over into humans is the contentious issue. </p>
<p>One widely supported hypothesis is the spillover occurred in the “wet markets” of Wuhan, where many species of wildlife from across China are held in crowded conditions.</p>
<p>However, there’s no evidence the species of bats in which the closest relatives of SARS-CoV-2 are found were sold through the Wuhan wet markets at any time in the <a href="https://www.nature.com/articles/s41598-021-91470-2">two years before the pandemic</a>. This hypothesis requires the existence of a “bridge host”, another species that becomes infected via spillover from the original bat hosts, and then passes the virus onto humans.</p>
<p>Bridge hosts are well-known in many emerging human diseases. For example, Hendra virus, which my group studies, has flying foxes as its reservoir. Hendra spills over to horses <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2014.2124">with some frequency</a>. Horses then amplify the virus as a bridge host and can infect humans.</p>
<p>Fortunately, this is extremely rare, with only <a href="https://www.health.nsw.gov.au/Infectious/controlguideline/Pages/hendra-case-summary.aspx">seven known cases</a>. Tragically, four of those people died. Hendra has never been known to spread directly from flying foxes to humans.</p>
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Read more:
<a href="https://theconversation.com/i-was-the-australian-doctor-on-the-whos-covid-19-mission-to-china-heres-what-we-found-about-the-origins-of-the-coronavirus-155554">I was the Australian doctor on the WHO's COVID-19 mission to China. Here's what we found about the origins of the coronavirus</a>
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<h2>More evidence a lab leak is very unlikely</h2>
<p>A second, much more <a href="https://theconversation.com/the-covid-19-lab-leak-hypothesis-is-plausible-because-accidents-happen-i-should-know-162430">contentious hypothesis</a> is the origin of the pandemic was the result of a “lab leak”. </p>
<p>Wuhan has one of the most sophisticated virological laboratories in China, and the laboratory does work on bat viruses. The suggestion is the virus may have inadvertently been released into the general community via one of the workers. No direct evidence supports this hypothesis.</p>
<p>A new pre-print study, <a href="https://virological.org/t/evidence-against-the-veracity-of-sars-cov-2-genomes-intermediate-between-lineages-a-and-b/754">released online this month</a>, provides <a href="https://www.nature.com/articles/d41586-021-02519-1">strong evidence</a> to support the “natural spillover” hypothesis, with results that are hard to reconcile with the “lab leak” hypothesis.</p>
<p>The study is yet to be peer reviewed. But it’s based on a detailed examination of the genetic sequences of two early lineages obtained from people infected in late 2019 and early 2020. </p>
<p>For convenience, these two lineages are called A and B. The two lineages differ by just two nucleotides (letters in the genetic code) at two different key sites in the genetic sequence.</p>
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<p>If there was a single lab escape event, the separation into lineages A and B must have happened after the lab escape. We would therefore expect to see a substantial number of intermediate lineages, with the lineage A nucleotide at one site, and the lineage B nucleotide at the other site.</p>
<p>However, if almost all of the genetic sequences obtained from humans are “pure” lineage A or pure lineage B, this suggests there were at least two different spillover events, either directly from bats or via bridge hosts. </p>
<p>And the evolution of the two lineages occurred before humans were infected.</p>
<p>The researchers downloaded all complete genetic sequences for SARS-CoV-2 that had been lodged in a widely used genomic database. Of these sequences, 369 were lineage A, 1,297 were lineage B and just 38 were intermediates. </p>
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Read more:
<a href="https://theconversation.com/why-it-will-soon-be-too-late-to-find-out-where-the-covid-19-virus-originated-166743">Why it will soon be too late to find out where the COVID-19 virus originated</a>
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<p>Genetic sequencing isn’t perfect. Close examination of the 38 intermediates strongly suggested they were more likely to be sequencing errors of pure lineage A or lineage B than to be true intermediates.</p>
<p>The genetic evidence, therefore, suggests very strongly there have been at least two separate spillover events into human populations, one being from lineage A and another being from lineage B.</p>
<h2>Did a human bring SARS-CoV-2 to the wet markets?</h2>
<p>The data don’t tell us there have been only two spillover events — there may have been more. Nor do they tell us whether these spillovers happened directly from bats, or whether some or all happened via an intermediate bridge host.</p>
<p>A Nature news article suggests this evidence <a href="https://www.nature.com/articles/d41586-021-02519-1">points to the spillover having happened via the wildlife trade</a>, but I think this is taking it a step too far. </p>
<p>While some of the wildlife species sold through the Wuhan wet market can indeed become infected with SARS-CoV-2 (for example <a href="https://wwwnc.cdc.gov/eid/article/26/12/20-3733_article">raccoon dogs</a> and <a href="https://www.sciencedirect.com/science/article/pii/S1473309920309129?via%3Dihub">mink</a>), there’s no evidence any sold through the market were infected.</p>
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<p>Many of the earliest human viral sequences (all lineage B) were recovered from the Wuhan seafood market, but wet markets and abattoirs are well-known to be places where the SARS-CoV-2 virus spreads very well from human to human.</p>
<p>So, it may have been a human who brought the virus to the Wuhan seafood market, rather than a species of wildlife.</p>
<p>One thing we do know is this pandemic originated through a human coming in contact with another species infected with the virus.</p>
<p>It’s unknown whether this was a bat or a bridge host, and whether this contact occurred in a wildlife market, or in a bat cave, or somewhere else entirely different.</p>
<p>Nevertheless, as humans encroach more and more on the habitats of wild animals and as wild animals are brought more frequently into close contact with humans, we can expect further spillovers and pandemics to occur.</p>
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<strong>
Read more:
<a href="https://theconversation.com/how-do-viruses-mutate-and-jump-species-and-why-are-spillovers-becoming-more-common-134656">How do viruses mutate and jump species? And why are 'spillovers' becoming more common?</a>
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<img src="https://counter.theconversation.com/content/168473/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hamish McCallum receives funding from the Australian Reserch Council and from the US agencies NSF, NIH and DARPA</span></em></p>It’s more evidence a lab leak is very unlikely.Hamish McCallum, Director, Centre for Planetary Health and Food Security, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1388612020-06-02T04:47:03Z2020-06-02T04:47:03ZThe next global health pandemic could easily erupt in your backyard<figure><img src="https://images.theconversation.com/files/338733/original/file-20200601-78867-6bv9ht.jpeg?ixlib=rb-1.1.0&rect=0%2C346%2C2008%2C1054&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Flickr</span></span></figcaption></figure><p>We know the virus that causes COVID-19 is linked to very similar viruses in bats, possibly passed to humans via an intermediate species <a href="https://advances.sciencemag.org/content/early/2020/05/28/sciadv.abb9153">such as pangolins</a>. The chance of a similar pandemic breaking out in Australia might seem far-fetched. But in fact, we tick all the boxes.</p>
<p><a href="https://www.nature.com/articles/s41467-017-00923-8">Hotspots</a> for emerging infectious diseases exist where human activities collide with a richness of animal species – and hence, high rates of microbial biodiversity. </p>
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Read more:
<a href="https://theconversation.com/most-laws-ignore-human-wildlife-conflict-this-makes-us-vulnerable-to-pandemics-135191">Most laws ignore ‘human-wildlife conflict’. This makes us vulnerable to pandemics</a>
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<p>As <a href="https://www.nature.com/articles/s41467-017-00923-8">research</a> has shown, Australia is such a place. Across the continent, particularly the east coast, natural landscapes have been <a href="https://www.wenfo.org/aer/#gallery-3">severely damaged</a> by human activity such as land clearing and <a href="https://www.theguardian.com/environment/ng-interactive/2018/apr/05/murray-darling-when-the-river-runs-dry">mismanagement of river systems</a>. This has led to forest loss, drying wetlands, biodiversity decline and bushfires.</p>
<p><a href="https://www.discovermagazine.com/health/coronaviruses-often-start-in-animals-heres-how-those-diseases-can-jump-to">All animals</a> harbour viruses and other pathogens. And when <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1247383/?tool=pmcentrez&report=abstract">environmental pressures</a> force animals into contact with humans, the results can be catastrophic. </p>
<h2>A world of disease</h2>
<p>In humans, around <a href="https://environmentlive.unep.org/media/docs/assessments/UNEP_Frontiers_2016_report_emerging_issues_of_environmental_concern.pdf">three-quarters</a> of all emerging infectious diseases are spread by non-humans. A new infectious disease emerges in humans <a href="http://ebrary.ifpri.org/cdm/ref/collection/p15738coll2/id/126825">every four months</a>. </p>
<p>In Africa, <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/mam.12173">the Ebola virus</a> resulted from human contact with fruit bats, and AIDS was caused by a pathogen that jumped from non-human primates <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1247383/?tool=pmcentrez&report=abstract#b61-ehp0112-001092">during road-building</a>. </p>
<p>In the United States, <a href="https://www.mayoclinic.org/diseases-conditions/lyme-disease/symptoms-causes/syc-20374651">Lyme disease</a> is caught from deer ticks. And the brain-damaging <a href="https://academic.oup.com/cid/article/34/Supplement_2/S48/459309">Nipah virus</a> originated in Malaysia after bats infected pigs, which passed the disease to farmers.</p>
<p>In China and elsewhere, the deforestation of pangolin habitat makes them easy targets for <a href="https://theconversation.com/400-000-african-pangolins-are-hunted-for-meat-every-year-why-its-time-to-act-111540">hunters and poachers</a>, who covet the animals for their meat and scales.</p>
<h2>Australia is not immune</h2>
<p>In Australia, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3734451/">a 2013 review</a> found at least 20 human diseases associated with disturbed natural environments between 1973 and 2010. They include:</p>
<p><strong>Hendra virus</strong>: This virulent disease first broke out at a racing stable <a href="https://www.business.qld.gov.au/industries/service-industries-professionals/service-industries/veterinary-surgeons/guidelines-hendra/incident-summary">in Hendra</a>, Brisbane in 1994. It causes catastrophic neurological and respiratory symptoms in horses, and more than 100 died. Seven people have been infected, four of whom died. </p>
<p>The virus is endemic to Australian flying foxes. It spilled over to people via horses who ate pasture containing flying-fox urine. <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0209798">Habitat loss</a> forced flying foxes to move close to humans to find food. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/338734/original/file-20200601-78845-1xjvsnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/338734/original/file-20200601-78845-1xjvsnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=366&fit=crop&dpr=1 600w, https://images.theconversation.com/files/338734/original/file-20200601-78845-1xjvsnd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=366&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/338734/original/file-20200601-78845-1xjvsnd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=366&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/338734/original/file-20200601-78845-1xjvsnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=460&fit=crop&dpr=1 754w, https://images.theconversation.com/files/338734/original/file-20200601-78845-1xjvsnd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=460&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/338734/original/file-20200601-78845-1xjvsnd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=460&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Biosecurity officers taking a swab from a horse during the 2008 Hendra virus outbreak.</span>
<span class="attribution"><span class="source">Dave Hunt/AAP</span></span>
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<p><strong>West Nile virus</strong>: This causes brain inflammation and death in <a href="https://www.who.int/news-room/fact-sheets/detail/west-nile-virus">humans, horses and birds</a>. An endemic strain in Australia is transmitted by mosquitoes from wild birds. In 2011 an outbreak affected <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4982165/">about 900 horses</a> in southeastern Australia of which about <a href="https://www.horsetalk.co.nz/2019/10/30/virulent-west-nile-virus-australia/">ten per cent died</a>. </p>
<p>The virus emerged in Australia unexpectedly, probably due to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4982165/">changed environmental conditions</a> such as climate change and habitat clearing.</p>
<p><strong>Australian bat lyssavirus</strong>: <a href="https://www.ncbi.nlm.nih.gov/pubmed/32311218">this rabies-like virus</a> can be transmitted from bats to humans, causing <a href="http://conditions.health.qld.gov.au/HealthCondition/condition/14/217/10/australian-bat-lyssavirus">serious illness</a> leading to paralysis, delirium, convulsions and death. </p>
<p>A vaccine administered after exposure can prevent the virus from taking hold. But since 1996, three people who did not receive the vaccine after being bitten or scratched by bats died of the virus. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/338737/original/file-20200601-78885-igzpso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/338737/original/file-20200601-78885-igzpso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=570&fit=crop&dpr=1 600w, https://images.theconversation.com/files/338737/original/file-20200601-78885-igzpso.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=570&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/338737/original/file-20200601-78885-igzpso.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=570&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/338737/original/file-20200601-78885-igzpso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=716&fit=crop&dpr=1 754w, https://images.theconversation.com/files/338737/original/file-20200601-78885-igzpso.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=716&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/338737/original/file-20200601-78885-igzpso.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=716&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A severe case of Buruli ulcer, which is on the rise in regional Victoria.</span>
<span class="attribution"><span class="source">Medical Journal of Australia</span></span>
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<p><strong>Buruli ulcer</strong>: <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5749465/?tool=pmcentrez&report=abstract">this disease</a>, also known as Bairnsdale ulcer and Daintree ulcer, is caused by a bacterium that destroys skin cells, small blood vessels and the fat under the skin. It causes long-term deformities. The bacterium, <em>Mycobacterium ulcerans</em>, occurs naturally in mosquitoes, vegetation and some possum droppings.</p>
<p>Australia is the <a href="https://wildlifehealthaustralia.com.au/Portals/0/Documents/FactSheets/Public%20health/Mycobacterium_ulcerans_disease.pdf">only developed country</a> with significant local transmission of Buruli ulcer and the only country to report the disease in wild animals such as possums. The number of people infected in Australia recently increased significantly in Victoria, to <a href="https://wildlifehealthaustralia.com.au/Portals/0/Documents/FactSheets/Public%20health/Mycobacterium_ulcerans_disease.pdf">340 new cases in 2018</a>. </p>
<h2>Australia: a disease-risk hotspot</h2>
<p>A <a href="https://www.nature.com/articles/s41467-017-00923-8">map</a> published in Nature Communications in 2017 showed Australia’s east coast to be a global hotspot for risk of emerging infectious diseases. </p>
<p>Australia continues to lose forest cover at alarming rates and biodiversity is suffering unprecedented decline and disruption. This <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2019.2736">increases the probability</a> of animal-human interaction. </p>
<p><a href="https://www.researchgate.net/publication/229789364_Drought-induced_mosquito_outbreaks_in_Wetlands">Drying wetlands</a> such as in the <a href="https://www.theguardian.com/environment/ng-interactive/2018/apr/05/murray-darling-when-the-river-runs-dry">Murray Darling Basin</a> destroy mosquito competitors such as aquatic animals that eat mosquito larvae. This allows mosquitoes to emerge in large numbers when water returns. This may trigger the emergence of infections such as the debilitating <a href="https://theconversation.com/explainer-the-chikungunya-virus-and-its-risk-to-australia-16968">chikungunya virus</a>.</p>
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Read more:
<a href="https://theconversation.com/australias-drought-could-be-increasing-q-fever-risk-but-there-are-ways-we-can-protect-ourselves-112297">Australia’s drought could be increasing Q fever risk, but there are ways we can protect ourselves</a>
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<p>Environmental damage can also make humans more susceptible to the effects of infectious diseases. For example, bushfires (driven in part by human-caused climate change) trigger smoke plumes that <a href="https://theconversation.com/wildfire-smoke-worsens-coronavirus-risk-putting-firefighters-in-extra-danger-136016">increase</a> the risk of dying from coronavirus. </p>
<p>Such diseases can also be catastrophic for species other than humans. <a href="https://www.sciencedirect.com/science/article/abs/pii/S1754504815001208">Chytrid fungus</a>, the most devastating disease on record to affect vertebrates, was first found in Australia in the 1970s. It had emerged in the early 20th century <a href="https://science.sciencemag.org/content/360/6389/621">on the Korean Peninsula </a>, alongside a commercial trade network in amphibians. It <a href="https://www.sciencedirect.com/science/article/abs/pii/S0006320717304020">continues to cause the extinction</a> of amphibian species worldwide. </p>
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<img alt="" src="https://images.theconversation.com/files/338735/original/file-20200601-78875-15eqxfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/338735/original/file-20200601-78875-15eqxfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/338735/original/file-20200601-78875-15eqxfl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/338735/original/file-20200601-78875-15eqxfl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/338735/original/file-20200601-78875-15eqxfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/338735/original/file-20200601-78875-15eqxfl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/338735/original/file-20200601-78875-15eqxfl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Drying wetlands in the Murray Darling basin increase the risk of disease outbreak.</span>
<span class="attribution"><span class="source">Dean Lewins/AAP</span></span>
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</figure>
<h2>What goes around comes around</h2>
<p>It’s clear human health depends on healthy ecosystems. But this undeniable fact is too often overlooked in policy decisions that allow environmental destruction. </p>
<p>Australia is an environmental and disease-risk hotspot. As a recent <a href="https://www.dea.org.au/wp-content/uploads/2020/05/Open-letter---EPBC-Review-.pdf">open letter</a> from prominent health leaders warned, the failure to conserve our environment dismantles our life-support systems and accelerates catastrophic climate change. </p>
<p>For humans to survive in our rapidly changing world, we must urgently strengthen and link policies of human health, environment and climate reform. </p>
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<strong>
Read more:
<a href="https://theconversation.com/from-the-bushfires-to-coronavirus-our-old-normal-is-gone-forever-so-whats-next-134994">From the bushfires to coronavirus, our old 'normal' is gone forever. So what's next?</a>
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<img src="https://counter.theconversation.com/content/138861/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bill Laurance receives funding from the Australian Research Council and other scientific and philanthropic sources. He is director of the Centre for Tropical Environmental and Sustainability Science at James Cook University, and founder and director of ALERT -- the Alliance of Leading Environmental Researchers & Thinkers.
</span></em></p><p class="fine-print"><em><span>Penny van Oosterzee 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 has been identified as a hotspot for emerging diseases, which occurs when human activities collide with a richness of animal species.Penny van Oosterzee, Adjunct Associate Professor James Cook University and University Fellow Charles Darwin University, James Cook UniversityBill Laurance, Distinguished Research Professor and Australian Laureate, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1342262020-05-12T15:29:36Z2020-05-12T15:29:36ZHuman activities are responsible for viruses crossing over from bats and causing pandemics like coronavirus<figure><img src="https://images.theconversation.com/files/332082/original/file-20200502-42923-1jb2q4v.jpg?ixlib=rb-1.1.0&rect=16%2C0%2C5542%2C3700&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Egyptian pipistrelle bat is one of seven bat species associated with spreading the coronavirus Middle East Respiratory Syndrome.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Viruses are naturally occurring entities. <a href="http://doi.org/10.1126/sciadv.1500527">Viruses have existed on Earth long before humans</a> and <a href="https://doi.org/10.1038/nrmicro2644">vastly outnumber humans</a>. There are <a href="https://doi.org/10.1038/nature19094">more viruses on Earth</a> than there are <a href="https://doi.org/10.1139/gen-2013-0152">stars in the universe</a> or <a href="https://www.tandfonline.com/doi/abs/10.3109/03014460.2013.807878">cells in the human body</a>. </p>
<p>As a cellular microbiologist who has studied <a href="http://dx.doi.org/10.1128/jmbe.v15i1.707">the origin and development of infectious diseases and their prevention</a>, understanding where infectious agents come from is as important, if not more important, to understanding how to combat the rampant spread of diseases within the human population. </p>
<p>Fortunately, only a small fraction — <a href="http://doi.org/10.1098/rstb.2011.0354">about 200</a> — of this vast array of viruses can infect humans. Some of the better-known human viral infections include measles, varicella, polio, human papilloma virus, influenza and rhinoviruses, which are typically responsible for the common cold. </p>
<p>An even smaller number of viruses are responsible for the deadliest human infections that we have experienced. In recent decades these include rabies virus, human immunodeficiency virus (HIV), Ebola virus and now, infamously, coronaviruses. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/327416/original/file-20200413-174608-omeq7p.jpg?ixlib=rb-1.1.0&rect=9%2C0%2C2035%2C2026&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/327416/original/file-20200413-174608-omeq7p.jpg?ixlib=rb-1.1.0&rect=9%2C0%2C2035%2C2026&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/327416/original/file-20200413-174608-omeq7p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/327416/original/file-20200413-174608-omeq7p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/327416/original/file-20200413-174608-omeq7p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/327416/original/file-20200413-174608-omeq7p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/327416/original/file-20200413-174608-omeq7p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/327416/original/file-20200413-174608-omeq7p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A colour-enhanced image of SARS-CoV-2 virus particles, isolated from a patient.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/niaid/49597020648/in/album-72157712914621487/">(National Institute of Allergy and Infectious Diseases Integrated Research Facility)</a></span>
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</figure>
<p>Viruses that circulate in other animals can enter a human population when <a href="https://dx.doi.org/10.1086%2F652860">a variety of human activities</a> allow for consistent and regular interaction with naturally occurring reservoirs. These events involve repeated and routine <a href="http://doi.org/10.1056/NEJMra1108296">interaction of humans with these animal hosts</a>. </p>
<p>Some of these interactions take place through the following <a href="https://www.unenvironment.org/news-and-stories/story/six-nature-facts-related-coronaviruses">human activities</a>: hunting, butchering and farming (husbandry), as well as the global trade of animals and domestication of exotic animals as pets. Population growth, global travel and <a href="https://www.who.int/globalchange/summary/en/index5.html">climate change</a> that cause the disruption of habitats further provide opportunities for cross-species transfer.</p>
<h2>Cross-species transfer</h2>
<p>Many of the viruses that have affected us over the past 20 years have emerged from non-human reservoirs. Reservoirs are the source of viruses and other pathogens and can be located in animal populations or the natural environment. What is of note is that <a href="https://doi.org/10.1038/cddiscovery.2016.48">the original reservoir for many of these viruses are bats</a>. </p>
<p>Bats have been shown to be the <a href="https://dx.doi.org/10.1128%2FCMR.00017-06">natural reservoir</a> of numerous deadly human viruses. The specialized immune systems of bats allow multiple different types of viruses to persist within these hosts. The coexistence of these <a href="https://dx.doi.org/10.1098%2Frspb.2012.2753">viruses within the same host</a> in combination with the molecular makeup of viruses further allows for the emergence of deadly human diseases. Bats aren’t all bad though; they have an <a href="https://theconversation.com/its-wrong-to-blame-bats-for-the-coronavirus-epidemic-134300">important role in our ecosystem</a>. </p>
<h2>Current COVID-19 pandemic</h2>
<p>The current <a href="https://doi.org/10.1016/S0140-6736(03)15329-9">coronavirus pandemic has been traced to a wet market, called the Huanan Seafood Wholesale Market, in Wuhan, China</a>. Within these wet markets, numerous animals are held together in confined spaces and small cages. This setting is inherently stressful and can allow for the exchange and mixing of multiple different bodily fluids. Human handling of these animals allows for <a href="http://doi.org/10.1097/01.qco.0000244043.08264.fc">the viruses contained within these reservoirs to spill over into the human population</a>. This is further facilitated by the long working hours and stress of the handlers themselves, as well as cuts, scratches, bites or other wounds inflicted by the animals on their handlers. </p>
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Read more:
<a href="https://theconversation.com/coronavirus-live-animals-are-stressed-in-wet-markets-and-stressed-animals-are-more-likely-to-carry-diseases-135479">Coronavirus: live animals are stressed in wet markets, and stressed animals are more likely to carry diseases</a>
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<p>A similar confluence of factors was attributed to the 2002 outbreak of SARS, <a href="https://doi.org/10.1007/978-3-540-70962-6_13">which has been attributed to the virus crossing over from bats to civets</a>. The related MERS-CoV was <a href="http://dx.doi.org/10.3201/eid1911.131172">attributed to a bat reservoir in Saudi Arabia</a>.</p>
<h2>Ebola outbreaks</h2>
<p>Outbreaks of Ebola in West Africa (2014-16 and 2018-present) have been attributed <a href="https://dx.doi.org/10.1007%2F82_2017_11">to human interaction with bats</a>. Three subfamilies of fruit bats — <em>Hypsignathus monstrosus</em>, <em>Epomops franqueti</em> and <em>Myonycteris torquata</em> — <a href="https://doi.org/10.1038/438575a">have been identified as natural reservoirs for the Ebola virus</a>. </p>
<p>These bats <a href="https://www.sciencemag.org/news/2017/06/hunting-ebola-among-bats-congo">inhabit caves deep within the Ebola River Valley</a>. Cross-species transmission of the Ebola virus from bats to humans can occur either directly or via intermediary hosts such as non-human primates, horses or pigs. </p>
<p>Global travel allowed for the virus to <a href="https://www.who.int/csr/disease/ebola/en/">spread from Central Africa to West Africa, and subsequently Europe and North America</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/332081/original/file-20200502-42908-1oteam2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/332081/original/file-20200502-42908-1oteam2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/332081/original/file-20200502-42908-1oteam2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=339&fit=crop&dpr=1 600w, https://images.theconversation.com/files/332081/original/file-20200502-42908-1oteam2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=339&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/332081/original/file-20200502-42908-1oteam2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=339&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/332081/original/file-20200502-42908-1oteam2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=427&fit=crop&dpr=1 754w, https://images.theconversation.com/files/332081/original/file-20200502-42908-1oteam2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=427&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/332081/original/file-20200502-42908-1oteam2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=427&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 sign in Makoua, Congo, warns visitors that Ebola is present in the area, and to avoid handling any animals found dead.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<h2>The Hendra virus</h2>
<p>The Hendra virus (HeV) has been a persistent infection of <a href="https://doi.org/10.5694/j.1326-5377.1995.tb126050.x">horses and humans in Australia since 1994</a>. Transmission into the equine population has been attributed to <a href="https://doi.org/10.1016/S1473-3099(12)70158-5">food or water contaminated with bat feces, urine or saliva</a>. HeV originated in black flying foxes, and its transmission to horses and humans results in a severe respiratory disease. </p>
<p>Subsequent transmission from horses to humans involves the close contact of humans with the <a href="https://www.cdc.gov/vhf/hendra/transmission/index.html">bodily fluids of infected horses</a>. Fortunately, <a href="http://doi.org/10.1016/j.coviro.2016.02.004">horse-to-horse, human-to-horse and bat-to-human transmission of hendra virus (HeV) is currently limited</a>. As a result, <a href="https://www.who.int/health-topics/hendra-virus-disease">this viral infection has not lead to widespread infections or fatalities</a>.</p>
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<a href="https://images.theconversation.com/files/327418/original/file-20200413-109081-fryzhj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/327418/original/file-20200413-109081-fryzhj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/327418/original/file-20200413-109081-fryzhj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=447&fit=crop&dpr=1 600w, https://images.theconversation.com/files/327418/original/file-20200413-109081-fryzhj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=447&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/327418/original/file-20200413-109081-fryzhj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=447&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/327418/original/file-20200413-109081-fryzhj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=562&fit=crop&dpr=1 754w, https://images.theconversation.com/files/327418/original/file-20200413-109081-fryzhj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=562&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/327418/original/file-20200413-109081-fryzhj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=562&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">Black flying foxes (<em>Pteropus alecto</em>) roosting in the Redcliffe Botanical Garden in Brisbane, Australia.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/niaid/49597020648/in/album-72157712914621487/">(gailhampshire/flickr)</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<h2>The Nipah virus</h2>
<p>Nipah virus (NiV) infections have been occurring <a href="https://doi.org/10.1007/s00281-002-0106-y">in Bangladesh and Malaysia since 1998</a>. This virus causes respiratory disease and swelling of the brain — encephalitis — in pigs. Human contact with infected pigs results in severe encephalitis, fever and eventually death. This virus also emerged from fruit bats through a spill-over event with the <a href="https://doi.org/10.1007/s11908-006-0036-2">close proximity of living conditions</a> between humans, domesticated animals and the natural reservoir. </p>
<p>Altogether, it is clear that human activities play a role in the emergence or re-emergence of infectious diseases. The role of <a href="http://dx.doi.org/10.1038/cddiscovery.2016.48">bats as natural reservoirs</a> to numerous deadly human diseases is also very clear.</p>
<p>The uncertainty of subsequent outbreaks or pandemics is not related to how or why but rather a question of when.</p><img src="https://counter.theconversation.com/content/134226/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Narveen Jandu 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>Bats have been the reservoir for recent disease outbreaks, including SARS and the current COVID-19 pandemic. But it’s human activity that allows the virus to cross over.Narveen Jandu, School of Public Health & Health Studies, University of WaterlooLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/902312018-02-07T02:52:13Z2018-02-07T02:52:13ZThe Hendra vaccine has no effect on racehorse performance<figure><img src="https://images.theconversation.com/files/205005/original/file-20180206-14107-7g8ulw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A veterinarian about to administer the Hendra virus vaccine. </span> <span class="attribution"><span class="source">Kathrin Schemann</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Vaccination against the deadly Hendra virus in horses does not reduce their racing performance, according to new research published in the <a href="http://onlinelibrary.wiley.com/doi/10.1111/avj.12679/full">Australian Veterinary Journal</a>.</p>
<p>The research was done following concerns by some that the vaccine could impact on the performance of horses.</p>
<p>The new study should ease those concerns, and lead to an increased uptake of the vaccine for horses to protect them – and also protect the people who work with the horses (who are potentially at risk from the virus too).</p>
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Read more:
<a href="https://theconversation.com/why-horse-racing-in-australia-needs-a-social-licence-to-operate-79492">Why horse-racing in Australia needs a social licence to operate</a>
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<h2>A deadly discovery</h2>
<p>The <a href="http://conditions.health.qld.gov.au/HealthCondition/condition/14/217/363/Hendra-Virus-Infection">Hendra virus</a> was <a href="https://www.business.qld.gov.au/industries/service-industries-professionals/service-industries/veterinary-surgeons/guidelines-hendra/incident-summary">first identified in 1994</a> in a large outbreak in a thoroughbred racing stable in the Brisbane suburb of Hendra. In this outbreak, the horse trainer and 13 of his horses died, and the stable-hand became sick. Brisbane racing was cancelled for three weeks.</p>
<p>The Hendra virus spills over sporadically from <a href="https://www.ehp.qld.gov.au/wildlife/livingwith/flyingfoxes/viruses.html">fruit bats to horses</a>. It has caused <a href="http://www.ava.com.au/node/83967">60 outbreaks</a> of disease in Queensland and in northern New South Wales as far south as Kempsey.</p>
<p>To date, 102 horses and four people have died. The <a href="https://www.brisbanetimes.com.au/national/queensland/vet-dead-from-hendra-virus-20090902-f7c0.html">last human death</a> happened in 2009. A record number of 18 outbreaks occurred in 2011.</p>
<p>Four outbreaks occurred in unvaccinated horses in 2017. Three people – including two children – required hospitalisation and preventative emergency <a href="http://www.abc.net.au/news/rural/2015-04-01/human-hendra-drug,-treatment-not-prevention/6365472">post exposure treatment with monoclonal antibodies</a>.</p>
<h2>At last, a vaccine</h2>
<p>A horse vaccine for Hendra was finally developed following years of research <a href="https://theconversation.com/how-we-developed-the-hendra-virus-vaccine-for-horses-10429">involving the CSIRO</a>.</p>
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Read more:
<a href="https://theconversation.com/how-we-developed-the-hendra-virus-vaccine-for-horses-10429">How we developed the Hendra virus vaccine for horses</a>
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<p>On November 1, 2012 the Hendra virus (HeV) EquiVac vaccine for horses was made available under a special “minor or emergency use” <a href="https://apvma.gov.au/node/10926">permit</a> due to the urgent need for its release following the large number of outbreaks in 2011. In May 2015 the vaccine was <a href="https://apvma.gov.au/node/12876">fully registered</a>.</p>
<p>There is no vaccine available for people, but Queensland Health has conducted a <a href="https://vetpracticemag.com.au/hendra-antibody-humans/">successful early phase clinical trial</a> of monoclonal antibody treatment for people exposed to Hendra virus.</p>
<p>The Hendra vaccine for horses is promoted by many authorities, including the <a href="https://www.dpi.nsw.gov.au/animals-and-livestock/horses/health-and-disease/hendra-virus/faqs">New South Wales</a> and <a href="http://statements.qld.gov.au/Statement/2017/4/21/hendra-review-leads-to-stronger-engagement-with-stakeholders">Queensland</a> governments and the <a href="http://www.ava.com.au/hendra-virus">Australian Veterinary Association</a>, as the “single most effective way of reducing the risk of Hendra virus infection”.</p>
<h2>Low uptake of the vaccine</h2>
<p>But despite the vaccine protecting human and horse health, its uptake was low. </p>
<p>Our unpublished data suggest that just 26% of thoroughbred horses racing in southeastern Queensland received vaccinations between November 2012 and December 2016. Overall, only about <a href="http://onlinelibrary.wiley.com/doi/10.1111/avj.12679/full">14% of all Australian horses have been vaccinated</a>.</p>
<p>Some individuals and performance horse associations voiced their concerns about potential performance impacts caused by the vaccine during a <a href="https://www.parliament.qld.gov.au/work-of-committees/committees/AEC/inquiries/past-inquiries/rpt24-09-HendraVirusVacc">2016 Queensland Parliamentary inquiry</a>. For example the <a href="https://www.parliament.qld.gov.au/documents/committees/AEC/2016/rpt24-09-HendraVirusVacc/submissions/115.pdf">Thoroughbred Breeders Queensland Association</a> described anecdotes of alleged poor performance in some racehorses following Hendra vaccination. </p>
<p>In a <a href="https://www.ncbi.nlm.nih.gov/pubmed/28460752">study of 27 horse owners</a>, some also said they were concerned and uncertain about adverse reactions as they had heard about horses’ performance decreasing, horses aborting, becoming sterile, getting severely sick, or even dying due to the vaccine.</p>
<p>Some people also expressed such concerns over vaccination <a href="http://www.abc.net.au/news/rural/2015-01-29/concern-mounts-that-hendra-vaccine-has-health-risk-for-horses/6052344">via social</a> and <a href="http://www.theland.com.au/story/4917453/hendra-vaccine-bypass/">other media</a>.</p>
<p>In contrast, the <a href="http://www.ava.com.au/node/78034">Australian Veterinary Association</a> and a <a href="http://forum.thoroughbredvillage.com.au/hendra-vaccine-the-industry_topic46000.html">well known racehorse trainer</a> said Hendra vaccination did not impact performance of top racehorses. The <a href="https://www.parliament.qld.gov.au/documents/committees/AEC/2016/rpt24-09-HendraVirusVacc/submissions/151.pdf">Queensland Horse Council submission to the inquiry</a> also fully supported the vaccine. </p>
<h2>Let’s look at horse performance</h2>
<p>As a result of lacking objective information about any effect of vaccination on racing performance, the Queensland Racing Integrity Commission funded the University of Sydney’s Equine Infectious Disease Research Group to investigate the issue last year.</p>
<p>The extensive study examined performance data of 1,154 thoroughbreds over 12,066 race starts in the three months before and after receiving Hendra vaccination.</p>
<p>Each horse acted as its own control. Horses were selected if they had raced at one of the six major southeastern Queensland racetracks between July 2012 and December 2016.</p>
<p>The main measure of performance was the Timeform rating. Timeform rating is an internationally comparable measure of a horse’s performance in a race. It considers many factors including how the race was run and where the horse finished.</p>
<p>The study also compared the margin of the horse to the winner and whether a horse won the race, placed first to third or won any prize money.</p>
<h2>The results are in</h2>
<p>None of the analyses found any statistically significant difference in horse performance before and after vaccination.</p>
<p>The large number of horses and race starts studied allowed us to account for many factors that can affect horse performance, such as distance and track conditions. It provides very high confidence that performance is unaffected by vaccination.</p>
<p>It’s hoped the study’s findings will now increase the uptake of the Hendra vaccine. This would lead to a higher number of horses protected from this deadly disease. It would also result in prompter treatment of sick horses and improved horse welfare.</p>
<h2>Other concerns</h2>
<p>But there are <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0180062">other reasons for the poor uptake of the Hendra vaccination</a> that need to be addressed.</p>
<p>Costs can be a factor as each vaccination <a href="https://www.parliament.qld.gov.au/documents/committees/AEC/2016/rpt24-09-HendraVirusVacc/submissions/186.pdf">costs between A$80 and A$120</a> to be administered by a veterinarian. </p>
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Read more:
<a href="https://theconversation.com/why-bats-dont-get-get-sick-from-the-deadly-diseases-they-carry-55012">Why bats don't get get sick from the deadly diseases they carry</a>
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<p>The <a href="http://www.ava.com.au/node/83969">current vaccination protocol</a> requires a horse to have two initial vaccinations administered three to six weeks apart, followed by a booster at six months, followed by annual boosters. </p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/28460752">Other barriers for vaccination uptake</a> include a perceived low infection risk, fear of adverse reactions and opposition to regulations that mandate vaccination.</p>
<p>It is important to remember that Hendra virus disease is also a human health issue. </p>
<p>So the results of our study should remove the barrier to vaccination uptake that was based on misinformation around racing performance impacts. Horse trainers and owners can be confident that Hendra vaccination can prevent infection in horses, themselves and staff without adversely affecting their horse’s performance level.</p><img src="https://counter.theconversation.com/content/90231/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kathrin Schemann received funding from the Queensland Racing Integrity Commission to conduct the study. </span></em></p>New research shows that vaccination against the deadly Hendra virus in horses does not reduce their racing performance.Kathrin Schemann, Fellow in Veterinary Biostatistics and Epidemiology, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/550122016-02-23T03:53:44Z2016-02-23T03:53:44ZWhy bats don’t get get sick from the deadly diseases they carry<figure><img src="https://images.theconversation.com/files/112440/original/image-20160223-25888-uggp6h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Black-headed flying fox (right) among a grey-headed colony.</span> <span class="attribution"><span class="source">CSIRO/Michelle Baker</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Bats are a natural host for more than 100 viruses, some of which are lethal to people. These include Middle Eastern Respiratory Syndrome (<a href="http://www.health.gov.au/mers-coronavirus">MERS</a>), <a href="http://www.health.gov.au/internet/main/publishing.nsf/Content/ohp-ebola.htm">Ebola</a> and <a href="https://www.business.qld.gov.au/industry/agriculture/species/diseases-disorders/animals/hendra-virus">Hendra virus</a>. These viruses are among the most dangerous pathogens to humans and yet an infected bat does not get sick or show signs of disease from these viruses.</p>
<p>The recent Ebola outbreak in West Africa showed the devastating impact such diseases can have on human populations.</p>
<p>As treatments in the form of therapeutics or vaccines rarely exist for emerging diseases, future outbreaks of disease have the potential to result in similar outcomes.</p>
<p>Understanding disease emergence from wildlife and the mechanisms responsible for the control of pathogens in their natural hosts provides a chance to design new treatments for human disease.</p>
<h2>The path to discovery</h2>
<p>Until recently, bats were among the least studied groups of mammals, particularly in regard to their immune responses. </p>
<p>But even <a href="http://onlinelibrary.wiley.com/doi/10.1002/9781118818824.ch14/summary">early studies</a> of virus-infected bats provided clues that there may be differences in the immune responses of bats. It was observed that some bats were capable of clearing viral infection in the absence of an antibody response. </p>
<p>Antibodies are one of the hallmarks of the immune response and allow the host to respond more rapidly to subsequent infection when the same pathogen invades the body. The absence of a detectable antibody response within the bat was striking and drew our attention to the earliest stages of the immune response, called the innate immune system. </p>
<p>The recent sequencing of the <a href="http://science.sciencemag.org/content/339/6118/456.short">first bat genome</a> provided some of the first clues that the innate immune system may be key to the ability of bats to control viral infection. There is intriguing evidence for unique changes in innate immune genes associated with the evolution of flight, and bats are the only mammal capable of sustained flight.</p>
<p>Flight is energetically expensive and results in the production of oxygen radicals. In the research we speculated that bats have made changes to their DNA repair pathways to deal with the toxic oxygen radicals.</p>
<p>A number of innate immune genes intersect with the DNA repair pathways. These genes have also undergone changes, so it appears that the evolution of flight may have had inadvertent consequences for the immune system.</p>
<h2>Bat super immunity</h2>
<p>In humans and other vertebrates, infection with viruses triggers the induction of special proteins called <a href="http://www.britannica.com/science/interferon">interferon</a>. </p>
<p>This is one of the first lines of defence following infection. It starts the induction of a variety of genes, known as interferon-stimulated genes. These genes play specific roles in restricting viral replication in infected and neighbouring cells. </p>
<p>Humans and other mammals have a large family of interferons, including multiple interferon-alpha genes and a single interferon-beta gene. People have 17 type I interferons, including 13 interferon-alpha genes.</p>
<p>Analysis published today of the <a href="http://www.pnas.org/content/early/2016/02/17/1518240113">interferon region</a> of the Australian black flying fox reveals that bats have fewer interferon genes than any other mammal sequenced to date. They have only ten interferon genes, three of which are interferon-alpha genes.</p>
<p>This is surprising given that bats have this unique ability to control viral infections that are lethal in people and yet they can do this with a lower number of interferons. </p>
<p>Although interferons are essential for clearing infection, their expression is also tightly regulated. This is to avoid over-activation of the immune system, which can have negative consequences for the host.</p>
<p>The expression of interferon-alpha and interferon-beta proteins, which account for the majority of the antiviral response generated following viral infection, is normally undetectable in the absence of infection. It is rapidly induced following detection of a pathogen. </p>
<p>Yet we again see a difference in bats. The three interferon-alpha genes are continuously expressed in bat tissues and cells in the absence of any detectable pathogen. Bats appear to use fewer interferon-alpha genes to efficiently perform the functions of as many as 13 interferon-alpha genes in other species. And they have a system that is constantly ready to respond to infection. </p>
<p>Continual activation of the interferon response in other species can lead to over-activation of the immune response. This frequently contributes to the detrimental effects associated with viral infection, including tissue damage. In contrast, bats appear able to tolerate constant interferon activation and are continually primed for viral infection.</p>
<h2>The bat approach in others</h2>
<p>We are familiar with the important role bats play in the ecosystem as pollinators and insect controllers. They are now demonstrating their worth in potentially helping to protect people from infectious diseases.</p>
<p>The ability of bats to tolerate a constant level of interferon expression is poorly understood at the moment. But the identification of the unique expression pattern of interferons in bats is a first step in identifying new ways of controlling viruses in humans and other species.</p>
<p>If we can redirect other species’ immune responses to behave in a similar manner to that of bats, then the high death rate associated with diseases such as Ebola could be a thing of the past.</p>
<hr>
<p><em>Peng Zhou was a co-author of this article. He’s a researcher in pathogen discovery and antiviral immunity, formerly employed at Duke–National University of Singapore Medical School and CSIRO.</em></p><img src="https://counter.theconversation.com/content/55012/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michelle Baker receives funding from the Australian Research Council. </span></em></p>Bats can carry some of the deadliest diseases known to affect humans and yet they don’t seem to get sick. So what can we learn from a bat’s immune system?Michelle Baker, Research scientist, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/442352015-07-03T05:45:50Z2015-07-03T05:45:50ZNorthern development plan shows Australia’s fraught vision of our tropics<figure><img src="https://images.theconversation.com/files/87268/original/image-20150703-30171-1b2zgbo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An historian reading the government White Paper on developing northern Australia will realise we’re actually heading all the way back to the 1890s.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/lawson_matthews/2415335571/">andrew matthews/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><blockquote>
<p>Australia is a big blank map, and the whole people is constantly sitting over it like a committee, trying to work out the ways to fill it in.</p>
</blockquote>
<p>Written as long ago as 1911, the <a href="http://trove.nla.gov.au/work/10819532">words of journalist C.E.W. Bean</a>, later inventor of the Anzac legend, haunted me as I read <a href="https://northernaustralia.dpmc.gov.au/sites/default/files/papers/northern_australia_white_paper.pdf">Our North, Our Future</a>, the federal government’s White Paper on developing northern Australia, released on June 17, 2015. </p>
<p>For more than 100 years, white Australians have rallied to cries of northern development, obsessively figuring out how to fill in the country north of Capricorn lest Asians should come and take it or Aborigines reclaim it. </p>
<p>Indeed, the first medical research organisation, the Australian Institute of Tropical Medicine (AITM), was set up in Townsville in the decade after federation in order to <a href="https://dukeupress.edu/The-Cultivation-of-Whiteness/index-viewby=title&sort=.html">ascertain whether a working white race</a> might be implanted across our tropical territory. Or whether moist heat would sap the vitality and mentality of whites, and tropical germs destroy them.</p>
<p>One of its later directors, Raphael Cilento, a very proud white man and anti-Semite, spent his career in “the struggle to establish a tropical consciousness in Australia” — as he put it in the Queensland school text he wrote with Clem Lack, <a href="http://www.textqueensland.com.au/item/book/1e6ed5d19fc3219033ff9a76eff6a190">Triumph in the Tropics</a>. </p>
<h2>A veritable goldmine</h2>
<p>Consistent with the barrage of tropical boosterism, the current government wants yet again to unlock the potential of the North and settle millions of productive citizens above Capricorn. Only it’s inclined now to bang on about fostering a multi-racial economic powerhouse rather than making the world safe for virile white labourers. </p>
<p>Thus the government is planning, inaptly, to use “Australia Unlimited branding to showcase investor ready projects and specific northern opportunities” — surely unaware that novelist E.J. Brady, who coined the term <a href="http://trove.nla.gov.au/work/8621138?selectedversion=NBD2972726">Australia Unlimited</a>, hoped the Australian tropics would be purely white and free of pesky Aborigines and Chinese.</p>
<p>Indeed, “unlimited for whom?” is always an apposite question in the history of Australian nationalism.</p>
<p>As an historian of medicine, I found the White Paper’s emphasis on tropical health particularly intriguing. A Tropical Health Strategy is a key part of this ambitious plan to develop what may be called <a href="http://www.harpercollins.com.au/9780730408871/capricornia">Capricornia</a> (following the lead of novelist Xavier Herbert). </p>
<p><a href="https://northernaustralia.dpmc.gov.au/sites/default/files/papers/northern_australia_white_paper.pdf">Our North, Our Future</a> suggests two compelling reasons for building expertise in tropical medicine. Investment in research into “tropical” diseases, such as dengue fever, malaria, melioidosis, Australian bat lyssavirus, Hendra virus, Nipah virus, chikungunya, Murray Valley encephalitis, multidrug-resistant tuberculosis and “other emerging pathogens” would, the report says, make Australia “a leading hub for the development of tropical medicine”. </p>
<p>The federal government has <a href="http://trademinister.gov.au/releases/Pages/2015/ar_mr_150510.aspx">allocated A$6.9 million for basic research</a> on such “priority diseases” — many of them dubiously tropical, but obviously worth treating all the same. And found a further A$8.5 million to “commercialise research in new tropical therapeutics and diagnostics”.</p>
<p>Understandably, Louis Schofield, the director of the Australian Institute of Tropical Health and Medicine, a reinvention of the AITM (but note the tactful insertion of health), has welcomed the investment. </p>
<p>“By promoting commercialisation and the creation of science/industry networks,” <a href="http://www.jcu.edu.au/research/JCU_147417.html">Professor Schofield announced</a>, “this funding initiative plays to Australia’s scientific strengths in the future economy of the Pacific Rim.”</p>
<h2>Pharmaceutical cashcow</h2>
<p>The government’s obsession with commercial opportunities in alleviating tropical disease is revealing. Certainly, it fits with technocratic, disease-centred, top-down programs of global health organisations such as the Bill and Melinda Gates Foundation. </p>
<p>“In calling the world’s researchers to develop innovative solutions to ‘the most critical challenges in global health’,” writes <a href="http://www.thelancet.com/pdfs/journals/lancet/PIIS0140673605664793.pdf">public health researcher Anne-Emanuelle Birn in The Lancet</a>, “the Gates Foundation has turned to a narrowly conceived understanding of health as product of technical interventions divorced from economic, social, and political contexts.” </p>
<p>But Australia’s Tropical Health Strategy goes further, hoping to profit from such technical fixes. This reveals a sort of cargo-cult mentality: build the laboratories and commercial medical technologies will pile up, solving the problems of global disease and making us rich as well. </p>
<p>In <a href="https://muse.jhu.edu/journals/hum/summary/v001/1.1.lakoff.html">an influential 2010 article</a>, anthropologist Andrew Lakoff describes “two regimes of global health”: what drives global health, he argues, is either concern with biosecurity, with emerging disease threats, or the humanitarian engagement of organisations like Médecins sans Frontières, which seeks to relieve suffering.</p>
<p>Naively, Lakoff failed to account for the “vision” of money-rubbing Australian politicians who imagine tropical medicine simply as a cash cow — or should that be a cash mosquito?</p>
<h2>Biosecurity fears</h2>
<p>Biosecurity is not forgotten, of course — how could it be in contemporary Australia? Apart from lucrative returns, the other main reason we should invest in tropical medicine, according to the White Paper, is to safeguard the nation from the threat of introduced diseases and pests. </p>
<p>Of course, this is an old saw, dating back to the first AITM: we must be vigilant against foreign bugs and the foreigners who spread them. We are told that “the Asia-Pacific region is a global epicentre for emerging infectious diseases and drug resistance”. </p>
<p>We are reminded that “the North’s proximity to our international neighbours, extensive coastline and sparse population makes it particularly vulnerable to biosecurity threats”. </p>
<p>Almost 100 years ago, Anton Breinl, the first director of the AITM, assured nationalist politicians that there was nothing inherently pathogenic in the tropics for whites. Rather, <a href="https://www.dukeupress.edu/The-Cultivation-of-Whiteness/index-viewby=title.html">they must protect vulnerable Europeans</a> from coloured races on the margins of Australia who had a proclivity for carrying germs especially noxious to white people. This was the medical rationale for immigration restriction.</p>
<p>The authors of this White Paper still seem to assume that disease comes from outside our borders, even if many of their “priority diseases”, such as Hendra, are in fact vernacular phenomena, genuine little Aussie battler viruses. </p>
<p>Now, I’m not denying there are frightening diseases emerging beyond our borders — just that in focusing exclusively on foreign threats we unrealistically limit the epidemiological palette. Evidently, in the biosecurity industry it’s hard to break such disabling xenophobic habits.</p>
<h2>The power of medicine</h2>
<p>If the White Paper is a reliable guide, tropical medicine is more important than ever in northern development. It has a timeworn contribution to make in securing us against disease threats, and an increasing role to play in generating pharmaceutical products and profits. </p>
<p>The authors express a touching confidence in tropical medicine, a faith in its efficacy that would have embarrassed even Breinl and Cilento. Indeed, so effective is modern tropical medicine that we can now allow those supposedly dodgy, previously disease-dealing foreigners within our borders to labour in the tropics. </p>
<p>Thus the White Paper recommends Designated Area Migration Agreements (DAMA) to permit foreign skilled and semi-skilled workers into a few northern zones. It promotes the <a href="https://employment.gov.au/seasonal-worker-programme">Seasonal Worker Programme</a> for labourers from the Pacific Islands and Timor Leste, as well as a new pilot program for workers from Kiribati, Nauru and Tuvalu. </p>
<p>A few pages earlier, these people and the places they come from were stigmatised as biosecurity risks, but presumably our tropical medicine industry can render them secure. Once used to justify keeping Asians and Pacific Islanders out of Australia, tropical medicine will now be employed to bring them in “safely”.</p>
<p>Too often, members of the infamous leftie lynch mob and other vaguely ABC-types protest that prime minister Tony Abbott is taking us back to the 1950s. But any Australian historian reading this White Paper will realise we’re actually heading all the way back to the 1890s, before federation, when unbridled capitalism and various forms of indentured labour were developing our North.</p>
<p>“Whose North?” we should ask, “whose triumph?”</p><img src="https://counter.theconversation.com/content/44235/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Warwick Anderson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The federal government’s recent White Paper on developing northern Australia has disturbing echoes of the 1890s, a time when unbridled capitalism and indentured labour developed the North.Warwick Anderson, Professorial Research Fellow, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/327992014-10-10T03:51:09Z2014-10-10T03:51:09ZWe still don’t know if domestic animals can spread Ebola<p>Spanish authorities have euthanised the dog of Madrid nurse Teresa Romero Ramos, who contracted Ebola. The 12-year-old dog, Excalibur, was not showing symptoms and was not tested for Ebola. But he lived with Romero Ramos when she became ill and was destroyed as a precaution, despite <a href="http://www.nytimes.com/2014/10/09/science/ebola-dog-excalibur-nurse-spain.html?_r=0">widespread protests</a>. </p>
<p>This has raised questions about the role domestic animals might play in the spread of Ebola. But before we get to dogs and cats, we need to start with bats – the natural host of Ebola and a number of other viruses including Hendra virus, <a href="https://theconversation.com/explainer-the-rabies-virus-28654">rabies</a>, <a href="https://theconversation.com/uk/topics/sars">SARS</a> (sudden acute respiratory syndrome) and <a href="https://theconversation.com/explainer-what-is-the-new-coronavirus-14193">MERS</a> (Middle East respiratory syndrom). </p>
<p>African fruit bats were established as the host of Zaire Ebola virus after antibodies were detected in a <a href="http://www.ncbi.nlm.nih.gov/pubmed/16319873">number of species</a>. Though interestingly, bats are not affected by the virus. </p>
<h2>Intermediate hosts in viral transmission</h2>
<p>For many of the viruses carried by bats, there is no evidence of direct bat-to-human transmission. More often than not, an intermediate host – or spillover host – gets infected following contact with infected bat material. </p>
<p>Spillover hosts generally develop severe disease and are capable of shedding the virus in large quantities, which can pass to people who come in close contact with secretions from the infected animals. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/61334/original/chs8wtts-1412902457.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/61334/original/chs8wtts-1412902457.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=789&fit=crop&dpr=1 600w, https://images.theconversation.com/files/61334/original/chs8wtts-1412902457.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=789&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/61334/original/chs8wtts-1412902457.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=789&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/61334/original/chs8wtts-1412902457.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=991&fit=crop&dpr=1 754w, https://images.theconversation.com/files/61334/original/chs8wtts-1412902457.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=991&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/61334/original/chs8wtts-1412902457.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=991&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ebola originated in African fruit bats.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/jomilo75/2182697390">jomilo75/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Intermediate hosts can include horses in the case of <a href="http://www.ncbi.nlm.nih.gov/pubmed/7701348">Hendra virus</a>, pigs for <a href="http://www.ncbi.nlm.nih.gov/pubmed/21632614">Nipah virus</a> and palm civets in the case of <a href="http://www.ncbi.nlm.nih.gov/pubmed/17042030">SARS</a>. </p>
<p>For Ebola, it is believed that contact with wild animals including gorillas, chimpanzees and antelope have <a href="http://www.ncbi.nlm.nih.gov/pubmed/24747773">been the source</a> of human infection. </p>
<p>Although the intermediate host is known for many bat-borne viruses, the role that other domestic animals play in the transmission cycle is largely unknown. </p>
<h2>Are domestic animals a risk?</h2>
<p>During previous Ebola outbreaks, scientists <a href="http://www.ncbi.nlm.nih.gov/pubmed/15757552">have found</a> virus specific antibodies in dogs. But the canines showed no symptoms. It’s still unclear whether dog-to-human transmission is possible, as is the mechanism by which dogs and other domestic animals become infected. </p>
<p>A similar situation occurred in <a href="http://www.abc.net.au/news/2011-07-31/family-devastated-after-euthanasing-hendra-dog/2818214">Australia in 2011</a> when Hendra virus specific antibodies were detected in a dog from a property where Hendra virus-infected horses were located. Again, we know little about the infection dynamics of this virus in dogs. </p>
<p>While cats are <a href="http://www.ncbi.nlm.nih.gov/pubmed/8894019">not resistant</a> to Hendra virus disease, <a href="http://www.ncbi.nlm.nih.gov/pubmed/9972433">natural transmission</a> from infected bats or horses to cats has not been demonstrated. </p>
<p>A complicating factor is that people who recover from infection with Hendra virus can experience a <a href="http://www.ncbi.nlm.nih.gov/pubmed/19473296">subsequent relapse</a> in disease. Whether viruses such as Ebola or Hendra virus can also lie dormant in domestic animals and reactivate at a later time point remains to be investigated.</p>
<h2>Opportunities for transmission</h2>
<p>While research is underway, the mechanisms involved in the transmission of Ebola and other bat-borne viruses to intermediate hosts is currently poorly understood. It seems to occur as a result of contact with bat secretions or partially eaten fruit which the bats chew and drop to the ground. </p>
<p>But the transmission of viruses from bats to other species depends, to a large extent, on opportunity. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/61335/original/wg5rwt4w-1412902671.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/61335/original/wg5rwt4w-1412902671.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/61335/original/wg5rwt4w-1412902671.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/61335/original/wg5rwt4w-1412902671.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/61335/original/wg5rwt4w-1412902671.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/61335/original/wg5rwt4w-1412902671.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/61335/original/wg5rwt4w-1412902671.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">Palm civets can be intermediate hosts of SARS.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/kabacchi/5028701905">Kabacchi/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Bats and viruses have long coexisted but interactions between bats and other species including humans have occurred only relatively recently. Urbanisation and deforestation has resulted in increased encroachment of humans and domestic animals into bat habitats.</p>
<p>Similarly, live animal markets such as those in Southern China, where SARS was detected in palm civets, are associated with close contact between a variety of different species and provide an ideal melting pot for spillover to take place. </p>
<p>Social and cultural practices also play a role in viral transmission including the consumption of “bush meat” from wild animals including non-human primates and bats. </p>
<p>In each of these situations, humans have provided the opportunity for interspecies contacts which would not have otherwise occurred. </p>
<p>Bats have an important place in our ecosystem, and there is so much we can learn from them. To help manage and prevent future outbreaks, we need a more comprehensive, science-based understanding of risks associated with the increased interaction of people and animals with wildlife.</p><img src="https://counter.theconversation.com/content/32799/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michelle Baker receives funding from The Australian Research Council.</span></em></p>Spanish authorities have euthanised the dog of Madrid nurse Teresa Romero Ramos, who contracted Ebola. The 12-year-old dog, Excalibur, was not showing symptoms and was not tested for Ebola. But he lived…Michelle Baker, Research scientist, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/124442013-02-26T03:30:26Z2013-02-26T03:30:26ZFirst Hendra, now bat lyssavirus, so what are zoonotic diseases?<figure><img src="https://images.theconversation.com/files/20628/original/c89h6hps-1361841879.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The global focus on emerging infectious disease has turned to bats since they were identified as the probable source of SARS.</span> <span class="attribution"><span class="source">Toby Mann</span></span></figcaption></figure><p>The last 30 years have seen a rise in emerging infectious diseases in humans, of which more than 70% are zoonotic. Zoonoses are diseases that normally exist in animals but have the potential to transmit to humans. They can be caused by many different infectious agents including bacteria, fungi and viruses.</p>
<p>Zoonotic infections have always been a part of the human disease landscape and most have come from domestic animals. The long lists includes anthrax, tuberculosis, plague, yellow fever and influenza. But with changes in environment, human behaviour and habitat destruction, these biosecurity threats are increasingly emerging from wildlife species. </p>
<p>Although it was established over a century ago that rabies was linked to bats, the research community was surprised to find that the SARS virus – which claimed more than 800 lives and cost more than $80bn globally – emerged from bats to civets and ultimately infected humans in the wet markets of southern China. </p>
<p>The <a href="http://www.who.int/en/">World Health Organization</a> (WHO) and most infectious disease experts agree that the source of the next human pandemic is likely to be zoonotic and wildlife is likely the prime suspect. While much effort has understandably gone into preparations for avian influenza, the next deadly pandemic may be the result of a currently unknown zoonotic agent. </p>
<p>Since the identification of bats as the probable source of the SARS epidemic, the global focus on emerging infectious disease has turned to them to understand and ultimately predict the source of the next human pandemic.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/20626/original/88bq22zd-1361841326.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/20626/original/88bq22zd-1361841326.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/20626/original/88bq22zd-1361841326.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/20626/original/88bq22zd-1361841326.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/20626/original/88bq22zd-1361841326.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=519&fit=crop&dpr=1 754w, https://images.theconversation.com/files/20626/original/88bq22zd-1361841326.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=519&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/20626/original/88bq22zd-1361841326.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=519&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Marburg virus emerged from bats in Africa and Asia.</span>
<span class="attribution"><span class="source">Microbe World/Flickr</span></span>
</figcaption>
</figure>
<p>In the last 20 years, a significant number of highly lethal viral diseases have emerged from bat species across the world. These include Hendra virus and Australian bat lyssavirus in Australia and Nipah virus in Malaysia and Bangladesh, where regular outbreaks reach mortality levels of 100%. Haemorrhagic fever viruses, including the feared and lethal Ebola and Marburg viruses, have also emerged from bats in Africa and Asia. </p>
<p>After crippling the globe in 2003 and 2004, SARS appeared to have vanished until last year when there was a deadly human SARS-like outbreak in Saudi Arabia. It killed six out of 12 infected patients and cases of infection continue to emerge. Known as SARI (severe acute respiratory infection), this infection has now shown the critical capacity to transmit from one person to another and, like its precursor, initial evidence supports its emergence from bats.</p>
<p>Zoonotic diseases in humans can take several different courses. For some, like rabies and West Nile virus, humans are “dead-end” hosts. That is, they transmit (spill over) from their animal reservoir (host) into humans but as there’s no subsequent human-to-human transmission, the disease is restricted from spreading. </p>
<p>Others, such as SARS and avian influenza, spill over to humans, cause disease and are able to transmit from person to person before being eradicated or “burning out” from the human population, leaving no residual infection except in its animal host. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/20625/original/nk3g9pt4-1361841236.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/20625/original/nk3g9pt4-1361841236.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=443&fit=crop&dpr=1 600w, https://images.theconversation.com/files/20625/original/nk3g9pt4-1361841236.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=443&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/20625/original/nk3g9pt4-1361841236.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=443&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/20625/original/nk3g9pt4-1361841236.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=557&fit=crop&dpr=1 754w, https://images.theconversation.com/files/20625/original/nk3g9pt4-1361841236.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=557&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/20625/original/nk3g9pt4-1361841236.jpg?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">Many animals carry viruses that can be transmitted to humans.</span>
<span class="attribution"><span class="source">Penn State</span></span>
</figcaption>
</figure>
<p>The third are diseases such as HIV AIDS, which spilled out of primates decades ago and has persisted in the human population ever since. And measles and mumps, which probably entered the human population thousands of years ago and are somewhat controlled but still circulating. </p>
<p>It’s impossible to completely safeguard against zoonotic diseases but steps can and are being taken to limit the opportunity for spill-over events through monitoring and rapid response when and where they do occur.</p>
<p>Controlling zoonotic diseases and protecting our animals, people and environment from increasing biosecurity threats will not only take a global effort but a multidisciplinary one. It cannot be addressed adequately with traditional human medical strategies where disease is fought in the human population only. </p>
<p>If we are to prepare and respond adequately to the next zoonotic attack, the approach needs to be diverse, taking in medical, veterinary, ecological and environmental factors. The transition will be complex, but necessary if we are to protect the global community from zoonotic disease as best as we can. After all, the stakes are high.</p><img src="https://counter.theconversation.com/content/12444/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The last 30 years have seen a rise in emerging infectious diseases in humans, of which more than 70% are zoonotic. Zoonoses are diseases that normally exist in animals but have the potential to transmit…Linfa Wang, Office of the Chief Executive Science Leader in Virology, CSIROGary Crameri, Virologist, Australian Animal Health Laboratory , CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/104292012-10-31T20:09:04Z2012-10-31T20:09:04ZHow we developed the Hendra virus vaccine for horses<figure><img src="https://images.theconversation.com/files/17099/original/zrzz2zzx-1351641925.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Scientists worked with Hendra virus at the highest level of biosafety within CSIRO’s Australian Animal Health Laboratory.</span> <span class="attribution"><span class="source">CSIRO</span></span></figcaption></figure><p>Today we are launching Equivac® HeV, the world’s first commercially available Hendra vaccine for horses. This breakthrough is the culmination of a scientific journey that dates back to the emergence of <a href="http://www.csiro.au/en/Outcomes/Food-and-Agriculture/Hendra-Virus.aspx">Hendra virus</a> in 1994.</p>
<p>Although the Hendra virus “disappeared” for some ten years (with only one case reported in 1999) after it was discovered in 1994, it has recently been identified every year in Queensland with serious consequences for the health of animals and people.</p>
<p>For my colleagues and I working at <a href="http://www.csiro.au/en/Organisation-Structure/National-Facilities/Australian-Animal-Health-Laboratory.aspx">CSIRO’s Australian Animal Health Laboratory</a> (AAHL), in Geelong, Victoria, and overseas, these outbreaks added urgency to our research on the Hendra virus.</p>
<p>The initial flurry of work following the emergence of the virus led to Australian mainland flying foxes being identified as the natural reservoir host of the virus.</p>
<p>Research waned somewhat towards the late 1990s, when a new virus – <a href="http://www.csiro.au/en/Outcomes/Food-and-Agriculture/Fighting-Nipah-virus.aspx">Nipah</a> – emerged in Peninsular Malaysia. Nipah virus was linked to outbreaks of fever and encephalitis in people, and with respiratory disease in farmed pigs.</p>
<p>Nipah was rapidly identified as being a close relative of the Hendra virus, and there are distinct similarities between the two. They both have the ability to lead to fatal infections in several species of animal, as well as in people. And they infect animal and human cells in a similar way.</p>
<p>Following the terrorist attacks on September 11, 2001, the US Congress dramatically increased the level of funding for research into countermeasures – including vaccines and antiviral drugs - for perceived potential bioterror threats, such as Nipah virus.</p>
<p>In collaboration with researchers of the Uniformed Services University of the Health Sciences, Maryland, we generated, in vitro, one of the Hendra and Nipah virus proteins (sG) that’s essential for infection and showed that antibodies to this protein can block virus replication.</p>
<p>These observations – that the G protein provoked a strong immune response in naturally occurring Hendra and Nipah virus infections, and that development of antibodies to the G protein was associated with virus clearance in infected people and animals – suggested a vaccine based on the G protein antigen may be a feasible scientific goal.</p>
<p>The frequency of Hendra virus incidents after 2005, particularly the Redlands outbreak of 2008 and infections at Cawarral in 2009 in which two people died following contact with infected animals, brought the desirability of a vaccine for horses more urgently into the frame.</p>
<p>All human infections with Hendra virus have occurred following exposure to infected horses and direct contact with their bodily fluids. We believed vaccinating horses would provide an opportunity to break the chain of virus transmission from flying foxes to horses, and then to people.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/17098/original/w8q44y9b-1351641920.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/17098/original/w8q44y9b-1351641920.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=426&fit=crop&dpr=1 600w, https://images.theconversation.com/files/17098/original/w8q44y9b-1351641920.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=426&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/17098/original/w8q44y9b-1351641920.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=426&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/17098/original/w8q44y9b-1351641920.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=535&fit=crop&dpr=1 754w, https://images.theconversation.com/files/17098/original/w8q44y9b-1351641920.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=535&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/17098/original/w8q44y9b-1351641920.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=535&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An artificially coloured electron micrograph of the Hendra virus.</span>
<span class="attribution"><span class="source">CSIRO/Alex Hyatt</span></span>
</figcaption>
</figure>
<p>Another benefit of a horse vaccine is that the horses themselves would be protected from a devastating infection that would otherwise most likely lead to their death.</p>
<p>As part of the ongoing research into countermeasures against biological threats, we’d developed the Hendra virus sG subunit vaccine with our US collaborators and tested it under laboratory conditions. The vaccine was formulated for use with an adjuvant (a substance that enhances the body’s immune response to an antigen) to enhance its efficacy. </p>
<p>Various forms of this preparation were evaluated in laboratory animals, where it was found to protect them from developing disease following exposure to Nipah and Hendra viruses and to prevent virus replication.</p>
<p>But a major hurdle to translation of this promising research into licensing for an equine vaccine was the lack of a commercial partner. This was a problem because the equine market is comparatively small, the infection problem largely confined to one state in Australia, and the public health impact of the disease is relatively insignificant compared to other illnesses.</p>
<p>Then, in 2010, a child received post-exposure treatment against Hendra virus infection after coming in close contact with an infected horse. This was closely followed by Queensland and Federal government funding to support the preliminary testing of the equine Hendra virus vaccine. This, in turn, acted as the catalyst for <a href="https://www.pfizeranimalhealth.com.au/home/default.aspx">Pfizer Animal Health</a> – our commercial partner - to join the research team.</p>
<p>The sG Hendra virus vaccine was soon formulated with a proprietary adjuvant suitable for use in horses. Early studies confirmed the development of immunity in vaccinated horses, prevention of disease following exposure to the virus, as well as the absence of viral shedding. This meant there was no risk of onward transmission to people or other susceptible animals.</p>
<p>In 2011, while this work was being undertaken, Australia witnessed an unprecedented spike in the number of Hendra virus cases in horses, in both Queensland and New South Wales. A total of 18 cases were identified. The first reported case of Hendra virus antibody detection in a dog outside of an experimental setting was also seen that year.</p>
<p><a href="http://www.daff.qld.gov.au/4790_20725.htm">Intergovernmental Hendra Virus Taskforce</a> was formed as a result, and additional funding was provided through the <a href="http://www.daff.qld.gov.au/4790_21026.htm">National Hendra Virus Research Program</a> to ensure that the equine Hendra virus vaccine project was able to progress as rapidly as possible.</p>
<p>Optimising the vaccine presented additional regulatory challenges, as did undertaking efficacy studies in horses at the highest level of laboratory biocontainment. At times, progress seemed frustratingly slow. But in reality, the availability of a vaccine to protect horses from Hendra virus infection and, in turn, prevent the exposure of people to this disease, has been swift. </p>
<p>The Equivac® HeV vaccine is an important step towards breaking the transmission cycle of this disease, and reducing its impact on the horse-owning community. But it’s important to ensure that we continue to protect the health of our animals and people. And to do this, we need to maintain and continue undertaking research and adding to the tools in our armoury of weapons against the deadly Hendra virus.</p><img src="https://counter.theconversation.com/content/10429/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deborah Middleton receives funding from NIH (US) and theAustralian Biosecurity CRC. She also has grants from the Intergovernmental Hendra virus Taskforce (Commonwealth, Qld State, NSW State) and the Commonwealth/Qld State governments.</span></em></p>Today we are launching Equivac® HeV, the world’s first commercially available Hendra vaccine for horses. This breakthrough is the culmination of a scientific journey that dates back to the emergence of…Deborah Middleton, Senior Veterinary Pathologist, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/65042012-04-23T05:09:51Z2012-04-23T05:09:51ZDealing with the threat of deadly viruses from Asia<figure><img src="https://images.theconversation.com/files/9797/original/qwpwvynp-1334884130.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Viruses passed from animals to humans pose a risk in Asia and Australia.</span> <span class="attribution"><span class="source">EPA/John Footy</span></span></figcaption></figure><p><strong><a href="https://theconversation.com/australia-in-the-asian-century-6391">AUSTRALIA IN THE ASIAN CENTURY</a> – A series examining Australia’s role in the rapidly transforming Asian region. Delivered in partnership with the Australian government.</strong></p>
<p><strong>Here, Professor Martyn Jeggo looks at how we might tackle deadly viruses emerging from Asia.</strong></p>
<p>Unlike most Hollywood disaster movies, last year’s <a href="http://www.imdb.com/title/tt1598778/">Contagion</a>, based on the scenario of a deadly virus originating in Asia sweeping the world, is not too far from the truth. </p>
<p>The movie’s fictitious virus is based on the <a href="http://www.who.int/mediacentre/factsheets/fs262/en/">Nipah virus</a>, which spreads from bats to pigs to humans. First discovered in Malyasia in 1998, Nipah has killed more than 100 people and led to the culling of more than a million pigs. There were 12 separate outbreaks last year alone.</p>
<p>Nipah is closely related to the <a href="https://theconversation.com/topics/hendra-virus">Hendra virus</a>, which was first isolated in Queensland in 1994 after it spread from bats, killing 14 horses and a horse trainer. More horses died in cases in Queensland and New South Wales last year and this time the virus was also detected in a dog. Nipah and Hendra have a mortality rate of 40% to 100%.</p>
<p>The threat of currently unknown virus-borne illness spreading across the world in the future is very much in the realm of possibility.</p>
<h2>The threat of zoonotic viruses</h2>
<p>Viruses are uniquely dangerous because of their ability to mutate and become deadly for existing and new hosts - a characteristic that makes them so much worse than a bacteria, mycoplasma or parasite. </p>
<p>Zoonotic viruses spread from animals to humans and are highly unpredictable. The range of who they can infect (host range) and their speed of transmission makes them a great and real threat. </p>
<p>Three-quarters of emerging viruses in humans have their origins in animals and many originate in South-East Asia. Why should this be? The growing need to feed an increasing population has led to more and more intensive farming practices, leading to close contact between farm workers and masses of animals.</p>
<p>The growing need to feed an increasing population has led to more and more intensive farming practices, leading to close contact between farm workers and masses of animals. Thousands, if not millions, of animals such as pigs and poultry are contained in relatively small areas, enabling viruses to infect large numbers of animals at a single site, and potentially mutate and become more virulent.</p>
<p>The 2003 SARS epidemic is the perfect example of a previously unknown virus causing chaos worldwide as it spread from China to Hong Kong and Canada. </p>
<p>A SARS-like virus was dormant in bats for some time before a chance mutation occurred. This change didn’t take place in a bat but in another host. The civet cat, which was almost certainly infected from bats, is commonly eaten by Chinese people and that’s how SARS was able to infect humans. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/9803/original/c54yzhjr-1334887798.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/9803/original/c54yzhjr-1334887798.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=389&fit=crop&dpr=1 600w, https://images.theconversation.com/files/9803/original/c54yzhjr-1334887798.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=389&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/9803/original/c54yzhjr-1334887798.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=389&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/9803/original/c54yzhjr-1334887798.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=489&fit=crop&dpr=1 754w, https://images.theconversation.com/files/9803/original/c54yzhjr-1334887798.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=489&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/9803/original/c54yzhjr-1334887798.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=489&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The SARS epidemic caused chaos in the region.</span>
<span class="attribution"><span class="source">EPA/STR</span></span>
</figcaption>
</figure>
<p>Chance virus mutations demonstrate the importance of keeping an open mind when considering what kind of viruses could emerge. We can’t rule out the possibility of wild birds from Asia migrating to the Top End of Australia, for instance, and mingling with native birds to introduce a new influenza virus type that we’ve never seen before. </p>
<p>While some of our most deadly zoonotic viruses originate in bats, they are invariably merely the carrier. Rarely do the viruses cause disease in bats. So our ongoing research into bat-borne viruses is focused on understanding “host switching”. </p>
<p>Similarly, understanding the spillover of influenza viruses from one host to the other, such as bird flu infecting people, will help us better manage risks.</p>
<h2>Embracing a one-health approach</h2>
<p>Population growth, livestock farming practices, climate change and our impact on the environment have disturbed the ecosystem and increased the risk of viruses spreading. There are also more of us travelling around the world, and that can only encourage the spread of viruses. </p>
<p>Only by considering the whole ecosystem in which bats, livestock and humans co-exist can we better understand what leads to the spread of viruses, and how best to curb their impact.</p>
<p>Looking at health controls for people working on intensive livestock farms in Asia might be one way to address this potential risk. But the growing popularity of more eco-farming practices, such as free-range chickens, could also be putting livestock at more risk. As they roam freely across open areas, animals potentially come in contact with wild birds carrying exotic viruses. </p>
<p>Traditionally, we’ve approached wildlife, animal and human diseases entirely separately. The way forward may be to take a “one-health” approach with scientists across all three disciplines working together to understand the system as a whole. To deal with zoonotic viruses, we need to understand the multidimensional links between wild animals, livestock production, the environment and global public health.</p>
<p>Understanding the mechanism of host switching and putting this in the context of our ecosystem is perhaps the best approach to predicting and preempting future virus risks. </p>
<p>This “one-health” approach has already been successful in the development of a vaccine against the Hendra virus. By working together, we realised that there really isn’t anything we could do about the bats. And that vaccinating people costs too much and takes too long. But from our bat-based research, we were able to create a vaccine for horses against Hendra expected to be available next year.</p>
<p>The introduction of the vaccine will mean horses are protected and can’t spread the disease so humans. People won’t be put at risk and the bats hosted the virus all along will no longer be considered such a threat. </p>
<p>Out ongoing research into viruses will take the guesswork out of the contagions that lie ahead. And that calls for a collective sigh of relief.</p>
<p><strong>This is part twelve of <a href="https://theconversation.com/australia-in-the-asian-century-6391">Australia in the Asian Century</a>. You can read other instalments by clicking the links below:</strong></p>
<p><strong>Part One: <a href="https://theconversation.com/want-to-get-ahead-this-century-learn-an-asian-language-6247">Want to get ahead this century? Learn an Asian language</a></strong></p>
<p><strong>Part Two: <a href="https://theconversation.com/australias-great-untapped-resource-chinese-investment-6197">Australia’s great, untapped resource … Chinese investment</a></strong></p>
<p><strong>Part Three: <a href="https://theconversation.com/beyond-china-australia-and-asias-northern-democracies-6348">Beyond China: Australia and Asia’s northern democracies</a></strong></p>
<p><strong>Part Four: <a href="https://theconversation.com/more-than-a-farm-on-top-of-a-mine-australias-soft-power-potential-in-asia-6328">More than a farm on top of a mine: Australia’s soft power potential in Asia</a></strong></p>
<p><strong>Part Five: <a href="https://theconversation.com/australia-can-lead-the-fight-against-asias-lifestyle-disease-epidemic-6239">Australia can lead the fight against Asia’s lifestyle disease epidemic</a></strong></p>
<p><strong>Part Six: <a href="https://theconversation.com/why-australia-needs-an-asian-century-institute-6217">Why Australia needs an Asian Century Institute</a></strong></p>
<p><strong>Part Seven: <a href="https://theconversation.com/taming-the-tigers-tourism-in-asia-to-become-a-two-way-street-6198">Taming the tigers: tourism in Asia to become a two-way street</a></strong></p>
<p><strong>Part Eight: <a href="https://theconversation.com/australia-will-need-a-strong-constitution-for-the-asian-century-6249">Australia will need a strong constitution for the Asian Century</a></strong></p>
<p><strong>Part Nine: <a href="https://theconversation.com/a-focus-on-skills-will-allow-australia-to-reap-fruits-of-its-labour-6306">A focus on skills will allow Australia to reap fruits of its labour</a></strong></p>
<p><strong>Part Ten: <a href="https://theconversation.com/engaging-with-asia-weve-been-here-before-6455">Engaging with Asia? We’ve been here before</a></strong></p>
<p><strong>Part Eleven: <a href="https://theconversation.com/china-india-and-australian-gas-who-controls-energy-in-the-asian-century-6243">China, India and Australian gas – who controls energy in the Asian Century?</a></strong></p>
<p><strong>Part Thirteen: <a href="https://theconversation.com/defence-agreements-with-us-harm-australias-reputation-in-asia-6298">Defence agreements with US harm Australia’s reputation in Asia</a></strong></p>
<p><strong>Part Fourteen: <a href="https://theconversation.com/as-asia-faces-climate-change-upheaval-how-will-australia-respond-6308">As Asia faces climate change upheaval, how will Australia respond?</a></strong></p>
<p><strong>Part Fifteen: <a href="https://theconversation.com/how-australia-can-become-asias-food-bowl-6202">How Australia can become Asia’s food bowl</a></strong></p><img src="https://counter.theconversation.com/content/6504/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Martyn Jeggo 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 IN THE ASIAN CENTURY – A series examining Australia’s role in the rapidly transforming Asian region. Delivered in partnership with the Australian government. Here, Professor Martyn Jeggo looks…Martyn Jeggo, Director, Australian Animal Health Laboratory, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/48072011-12-21T19:44:01Z2011-12-21T19:44:01Z2011: Year of the bat-borne virus<figure><img src="https://images.theconversation.com/files/6586/original/6ydsbbdj-1324341884.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Bats appear have a much better symbiotic relationship with viruses than other mammal species.</span> <span class="attribution"><span class="source">CSIRO</span></span></figcaption></figure><p>In the Chinese zodiac, 2011 is the year of the rabbit but for those of us working on viruses from wildlife animals, it was much more like the year of the bat.</p>
<p>In February, the <a href="http://www.asiaone.com/Health/News/Story/A1Story20110205-262058.html">deadly Nipah virus re-emerged in Bangladesh</a> killing at least 15 people. Nipah virus was first discovered in Malaysia during a large disease outbreak from 1998 to 1999. That outbreak resulted in around 100 human fatalities and more than one million pigs were culled in order to control the spread of the virus. </p>
<p>It’s well known that Nipah is a bat-borne virus, transmitted from bats to pigs, and then from pigs to people. Viruses that have this ability to pass from animals to people are commonly known as zoonotic viruses. </p>
<p>From June to October, Australia experienced its own zoonotic disease threat with 18 properties across <a href="http://www.dpi.qld.gov.au/4790_2900.htm">Queensland</a> and <a href="http://www.dpi.nsw.gov.au/agriculture/livestock/horses/health/general/hendra-virus">New South Wales</a> confirming cases of Hendra virus infections. This resulted in the death of 23 horses and, for the first time outside a laboratory setting, Hendra virus antibodies were identified in a dog. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/6588/original/8w2by2ps-1324342127.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/6588/original/8w2by2ps-1324342127.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/6588/original/8w2by2ps-1324342127.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/6588/original/8w2by2ps-1324342127.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/6588/original/8w2by2ps-1324342127.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/6588/original/8w2by2ps-1324342127.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/6588/original/8w2by2ps-1324342127.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">Bat-borne viruses spread from bats to pigs and from pigs to humans.</span>
<span class="attribution"><span class="source">Vicky Sawyer</span></span>
</figcaption>
</figure>
<p>During this worrying time, Queensland Health monitored 68 people for signs of infection due to potential exposure to the virus. Thankfully none of them showed any evidence of this.</p>
<p>In October, a <a href="http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1002304">paper published</a> in the journal <a href="http://www.plospathogens.org/home.action;jsessionid=4CF0EBE242740B4D610BDFB4DC248093">PLoS Pathogens</a> reported the discovery of a new Ebolavirus-like filovirus in Spanish bats, marking the first detection of this class of killer virus in Europe.</p>
<p>To add a dramatic finishing touch to these real-life events, the release of the <a href="https://theconversation.com/steven-soderberghs-contagion-sounding-alarm-for-the-next-pandemic-3907">Hollywood blockbuster Contagion</a> further drew the world’s attention to the potential damage a novel bat-borne virus could wreak. Although the movie is fictional, it’s a frighteningly realistic depiction of just how fast an infectious disease can take root and spread.</p>
<h2>Why bats?</h2>
<p>For the last two decades, we’ve witnessed several major disease outbreaks caused by deadly viruses, including Hendra, Nipah, Ebola, Marburg and SARS. <em>All</em> of these viruses originated from bats, yet none seem to cause any clinical disease in the bats, which are known as “reservoir hosts” as carriers of the virus. It appears that bats have a much better symbiotic relationship with viruses than other mammal species.</p>
<p><a href="http://cmr.asm.org/content/19/3/531.full">Recent research findings</a> from different international groups indicate there are numerous viruses circulating among the bat populations around the world. Work on coronavirus – the virus family to which SARS belongs – and paramyxovirus – the family to which human measles and Hendra viruses belong – suggests that all “modern” versions of human and livestock viruses may have a close relative in bats. This has led to the <a href="http://www.sciencedirect.com/science/article/pii/S1879625711001325">hypothesis</a> that bats could potentially be the “birth place” of most known viruses affecting humans. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/4644/original/COND-08358c2r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/4644/original/COND-08358c2r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4644/original/COND-08358c2r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4644/original/COND-08358c2r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4644/original/COND-08358c2r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4644/original/COND-08358c2r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4644/original/COND-08358c2r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Steven Soderbergh’s film Contagion drew attention to the havoc a bat-borne virus could wreak.</span>
<span class="attribution"><span class="source">Claudette Barius</span></span>
</figcaption>
</figure>
<p>Bats are very ancient mammals and have been around for at least 50 or 60 million years. They make a significant contribution to environmental health through their role as essential pollinators and seed dispersers for native forests and they’re the only mammal with true flying ability. </p>
<p>The unique virus-bat relationship is possibly the result of a long history of co-evolution. It may also be the case that the presence of low levels of different viruses in bats may actually have been, and continue to be, advantageous for the bat population.</p>
<p>Research conducted in Australia has demonstrated that although most bat populations show evidence of Hendra virus infection, the level of actively circulating virus is uniformly low. This explains why we’ve generally only experienced one or two events of host switching – from bats to horses – almost every year for the last decade. </p>
<p>But, there were at least 18 incidents of species-jumping for Hendra virus in 2011. This led to the thesis that an increase of Hendra virus in bats or a Hendra virus “spike” are the vital triggers for an outbreak. Research data obtained this year seems to support this hypothesis.</p>
<h2>Continuing research </h2>
<p>So the $12-million question is what happened in 2011 that’s different from previous years? After the dramatic increase of Hendra cases this year, the Commonwealth and state governments formed the <a href="http://www.dpi.qld.gov.au/4790_20725.htm">Intergovernmental Hendra Virus Taskforce</a> and provided A$12 million of funding for research into reducing or preventing future outbreaks by answering questions such as this. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/6589/original/9qhqx9jq-1324342435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/6589/original/9qhqx9jq-1324342435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=430&fit=crop&dpr=1 600w, https://images.theconversation.com/files/6589/original/9qhqx9jq-1324342435.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=430&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/6589/original/9qhqx9jq-1324342435.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=430&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/6589/original/9qhqx9jq-1324342435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=540&fit=crop&dpr=1 754w, https://images.theconversation.com/files/6589/original/9qhqx9jq-1324342435.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=540&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/6589/original/9qhqx9jq-1324342435.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=540&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Hendra virus outbreak in Queensland and New South Wales affected 18 porperties.</span>
<span class="attribution"><span class="source">AAP</span></span>
</figcaption>
</figure>
<p>As 2011 draws to an end, the story of bat-borne viruses continues. The world continues to change and it’s certain that more and more unknown bat viruses will emerge. The challenge for us is to get ahead of the viruses before they are given the opportunity to jump from one host to another. </p>
<p>The good news is that scientists around the world have already started to work towards developing a system for predicting virus outbreaks, similar to weather and earthquake forecasts, through the <a href="http://www.gvfi.org/">Global Virus Forecasting Initiative (GVFi)</a>, which is led by Stanford University’s Professor Nathan Wolf. </p>
<p>CSIRO’s “bat pack”, a team of researchers at the <a href="http://www.csiro.au/aahl">Australian Animal Health Laboratory (AAHL)</a> in Geelong, Victoria, is a partner of the GVFi. As the name suggests, the team’s research aims to better understand bat immunology and how bats co-exist with the viruses they carry. Our goal is to identify strategies to control viruses, such as Hendra, from spreading to other animals and people.</p>
<p>Last month, Australia extended its ability to respond to a wide range of continually emerging diseases – that have the potential to harm people, animals and our environment – further with the opening of <a href="http://www.csiro.au/en/Portals/Multimedia/CSIROvod/AAHL-Tour.aspx">the world’s most biosecure laboratory</a>. </p>
<p>The new state-of the-art laboratory is located within the high containment facility of AAHL and will provide researchers, such as members of the “bat pack”, with the biosecure and safe infrastructure required to undertake vital research to effectively tackle increasing biosecurity threats, both here and around the world.</p><img src="https://counter.theconversation.com/content/4807/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Linfa Wang receives funding from ARC, NHMRC, NIH and AB-CRC</span></em></p>In the Chinese zodiac, 2011 is the year of the rabbit but for those of us working on viruses from wildlife animals, it was much more like the year of the bat. In February, the deadly Nipah virus re-emerged…Linfa Wang, Office of the Chief Executive Science Leader in Virology, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/35292011-10-03T19:37:38Z2011-10-03T19:37:38ZConservation shouldn’t be a popularity contest<figure><img src="https://images.theconversation.com/files/4038/original/michis0806.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">People who get to know flying foxes are less likely to loathe them.</span> <span class="attribution"><span class="source">michis</span></span></figcaption></figure><p>Even Australia’s most iconic, charismatic species are in danger of extinction. Species such as the cassowary, <a href="http://theconversation.com/genome-map-project-uncovers-first-tasmanian-devil-to-fight-off-face-tumour-2051">Tasmanian devil</a> and <a href="http://theconversation.com/koalas-people-and-climate-change-not-a-good-mix-3108">koala</a> all enjoy significant community support and relatively generous funding and yet find themselves at risk.</p>
<p>And if our most popular species are in danger of extinction, what will become of our <em>un</em>popular species? </p>
<p>For species that are feared, disliked or even hated, conservation presents further challenges. Negative community attitudes show up as opposition to conservation efforts and to legislated protection. Unpopular species may even be deliberately harassed, harmed or killed, or have their habitat destroyed. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/4044/original/bat_and_bloodwood.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/4044/original/bat_and_bloodwood.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=902&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4044/original/bat_and_bloodwood.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=902&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4044/original/bat_and_bloodwood.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=902&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4044/original/bat_and_bloodwood.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1134&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4044/original/bat_and_bloodwood.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1134&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4044/original/bat_and_bloodwood.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1134&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Flying foxes are often feared, despite their beauty.</span>
<span class="attribution"><span class="source">Ray & Sue Udy</span></span>
</figcaption>
</figure>
<p>This is the case for flying foxes, particularly in rural NSW and Queensland, where tolerance for the animals has been traditionally low. </p>
<p>Flying foxes are disliked because they occasionally feed on fruit crops when native food supplies are short. They can also be noisy neighbours when roosting near residential areas. </p>
<p>They are feared because they can harbour <a href="http://www.csiro.au/science/Australian-bat-lyssavirus.html">lyssavirus</a> and <a href="https://theconversation.com/topics/hendra-virus">Hendra virus</a>, even though the risk to humans is extremely low. </p>
<p>Communities’ fear and hatred has been fanned in past decades by the media and conservative politicians, both in and out of parliament.</p>
<p>When referring to flying foxes, politicians and media commentators have used inflammatory language such as <a href="http://www.heraldsun.com.au/news/australian-bat-lyssavirus-discovery-triggers-new-killer-bat-alert/story-e6frf7jo-1226093945827">“killer bats”</a>, “horrible stinking vermin”, and <a href="http://www.dailytelegraph.com.au/news/opinion/the-reality-is-weve-all-gone-batty/story-e6frezz0-1226095897109">“disease-ridden pests”</a>.</p>
<p>Commentators claim that flying fox populations are “exploding” or “in plague proportions”. Residents living next to bat colonies have been said to live in “bat hell”; to be <a href="http://www.ntnews.com.au/article/2009/06/26/61871_ntnews.html">“terrorised”</a>, “under siege” or in a state of “war”. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/4033/original/Sheba_Also.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/4033/original/Sheba_Also.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=881&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4033/original/Sheba_Also.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=881&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4033/original/Sheba_Also.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=881&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4033/original/Sheba_Also.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1108&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4033/original/Sheba_Also.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1108&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4033/original/Sheba_Also.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1108&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">What’s not to like about flying foxes?</span>
<span class="attribution"><span class="source">Sheba_Also</span></span>
</figcaption>
</figure>
<p>Rarely do commentators focus on, or even mention, the crucial ecological role (pollination and seed dispersal) played by these animals, their uniqueness as flying mammals, their intriguing adaptation to <a href="http://animals.howstuffworks.com/mammals/question668.htm">hanging upside down</a>, their complex social interactions, their intelligence and <a href="http://anzang.samuseum.sa.gov.au/index.php?blog/show/2011-Overall-Winner.html">their pretty faces</a>. </p>
<p>The recent outbreaks of Hendra virus in Queensland and NSW have deepened the human-animal conflict even further. The outbreaks have encouraged more vilification of the animals and more <a href="http://www.abc.net.au/news/2011-09-30/flying-foxes-should-be-destroyed-katter/3193508?section=qld">calls for them to be culled</a>.</p>
<p>Governments have been slow – and in the case of Queensland, still unwilling – to list flying foxes as threatened species. This is despite evidence that two species declined by approximately 30% in ten years and that they suffer from habitat destruction and other threats from humans. </p>
<p>This reluctance may be due to the political implications of protecting deeply unpopular species in electorates with a lot of rural constituents. </p>
<p>A species’ conservation status (common, vulnerable or endangered) affects funding for data collection and conservation strategies. It also sets the level of penalties applicable for illegally harming or killing the species. </p>
<p>As such, it is essential that such status be accurate and based on scientific evidence, not on a species’ popularity or on political considerations. </p>
<p>Even after being listed as threatened species, the spectacled and grey headed flying foxes could still be legally shot by orchardists. Their camps can still be harassed and relocated. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/4034/original/aussiegall.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/4034/original/aussiegall.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4034/original/aussiegall.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4034/original/aussiegall.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4034/original/aussiegall.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4034/original/aussiegall.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4034/original/aussiegall.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">aussiegall</span></span>
</figcaption>
</figure>
<p>Shooting threatened species and deliberate destruction of their habitat is a rather unusual way to deal with threatened species. It would be unthinkable if it was any other species.</p>
<p>Laws for the protection of flying foxes have often been weakly enforced, or not at all. As a result, large amounts of illegal electrocution, shooting and harassment of camps have been allowed to go on unpunished.</p>
<p>Permit and license conditions have been weakly monitored, and when breached, governments have rarely been willing to prosecute. The few legal cases that have attempted to enforce the law for the protection of flying foxes have mostly been <a href="http://www.envlaw.com.au/ffox.html">initiated by private citizens</a>, not government conservation agencies. </p>
<p>So what can be done to protect unpopular species such as flying foxes? The answer lies with a multi-prong approach. </p>
<ul>
<li><p>There must be zero tolerance for the illegal killing or harassing of flying foxes. Turning a blind eye simply fosters further illegal activities.</p></li>
<li><p>Strategic and proactive education programs should start telling positive stories about much-maligned species such as bats. People are more likely to protect animals they know and like. </p></li>
</ul>
<p>In my experience as a wildlife carer, most people who claim to hate bats have never seen one close and know little about them. </p>
<ul>
<li><p>Governments must base decisions about threatened species management on scientific evidence, not political imperatives. </p></li>
<li><p>The most difficult goal to achieve is fostering an understanding that humans and wildlife share the same planet, whether we like it or not. </p></li>
</ul>
<p>Human-wildlife conflicts occur all over the world, from tigers killing people in remote villages, elephants trampling crops, wolves killing lambs, pigeons defecating over monuments and seals feeding on aquacultured fish. Culling animals in these circumstances cannot be a sustainable solution. </p>
<p>Unless these four elements are in place, it is likely that flying foxes will come under increasingly heavy attack each time a Hendra outbreak occurs. This could turn into uncontrollable killings with grave welfare and conservation outcomes. </p>
<p>There is hope though. If crocodiles can be viewed as an iconic, marketable species and a tourist attraction in northern Australia, despite the clear danger they pose, the same should surely be possible for flying foxes.</p><img src="https://counter.theconversation.com/content/3529/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dominique Thiriet is affiliated with the North Queensland Wildlife Care Inc.</span></em></p>Even Australia’s most iconic, charismatic species are in danger of extinction. Species such as the cassowary, Tasmanian devil and koala all enjoy significant community support and relatively generous funding…Dominique Thiriet, Lecturer, School of Law, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/32532011-09-12T04:02:57Z2011-09-12T04:02:57ZCulling bats isn’t the way to control Hendra virus<figure><img src="https://images.theconversation.com/files/3480/original/fruit_bat_shellac.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fruit bats carry disease, pollen and a warning about the state of the environment.</span> <span class="attribution"><span class="source">shellac/Flickr</span></span></figcaption></figure><p>This year has had the lot. First came the tempest, then the floods. Fires are on their way as the landscape dries out.</p>
<p>Now we have pestilence, in the form of <a href="https://theconversation.com/topics/hendra-virus">Hendra virus</a>. Calls for bat culls have ensued, but killing or relocating bats could make things worse for everyone. </p>
<h2>Vital pollinators: bats carry more than diseases</h2>
<p>Hendra virus is one of a number of recently emerged viruses which has spilled over from its usual wild-animal-hosts to domestic animals, and then to us. </p>
<p>Hendra’s repeated appearance this year has [caught public attention](<a href="http://www.abc.net.au/news/2011-08-25/hendra-virus-study-using-gps-to-track-bats/2854910">http://www.theaustralian.com.au/national-affairs/hendra-virus-spreads-treatments-limited/story-fn59niix-1226094172689</a>. Sadly much of that attention has not focused on the rarity of the disease or that transmission to humans occurs from exposure to sick horses. </p>
<p>Instead, it has focused strongly on control of the reservoir host of the virus: flying foxes. </p>
<p>Flying foxes are large bats found in forests along the whole of the east coast of Australia. They are important pollinators, and disperse the seed of native trees and shrubs. </p>
<p>In many environments, they are better at these tasks than birds, insects or the wind. In the wet tropics of northern Queensland, flying foxes help maintain the world heritage values of the tropical rainforest.</p>
<h2>Cute, furry, useful and hated</h2>
<p>Despite their ecological value, flying foxes are roundly disliked, especially by the citizens of towns which share space with a flying fox colony. </p>
<p>A recent paper by <a href="http://www.jcu.edu.au/law/staff/JCUDEV_002679.html">Dominique Thiriet</a> analyses the effect of unpopularity on species management. Shorn of academic niceties, she concludes it is hard to “sell” the value of creatures people dislike and even harder to implement science-based management regimes that conflict with the wisdom of public opinion.</p>
<p>Each time a disease crosses from bats to humans, there are immediate and sustained demands for bats to be culled or relocated from their roost sites. </p>
<p>These are rash ideas. There is a growing body of research that suggests relocation or culling will not reduce bat-associated disease and may even make matters worse.</p>
<p>The basis for this argument lies in the wider domain of <a href="http://www.izs.it/vet_italiana/2009/45_1/45_1.htm">One Health</a>, an idea which links human health and welfare to the health of the natural world. </p>
<h2>Bat illness can lead us to the bigger picture</h2>
<p>Overseas, spillover of viral diseases from bats has contributed to outbreaks of <a href="http://www.who.int/mediacentre/factsheets/fs262/en/">Nipah virus</a>, <a href="http://www.who.int/csr/sars/en/">SARS</a> and <a href="http://www.who.int/mediacentre/factsheets/fs103/en/">Ebola</a> virus. In each instance, the spillover has occurred in places with close associations between humans, their animals and bats in landscapes experiencing severe environmental stress. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/3481/original/fruit_bat_onkel_wart.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/3481/original/fruit_bat_onkel_wart.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/3481/original/fruit_bat_onkel_wart.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/3481/original/fruit_bat_onkel_wart.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/3481/original/fruit_bat_onkel_wart.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/3481/original/fruit_bat_onkel_wart.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/3481/original/fruit_bat_onkel_wart.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Culling won’t cure Hendra.</span>
<span class="attribution"><span class="source">onkel_wart</span></span>
</figcaption>
</figure>
<p>In Australia, the excretion of Hendra virus by bats varies by space and time. Outbreaks of disease are most likely at times of nutritional stress and when there has been severe environmental disturbance. This has certainly been the case in northern and southern Queensland this year. </p>
<p>One Health suggests the solutions lie in dealing with the underlying drivers of disease emergence. By focusing on the bats we are missing the big picture and another warning that our environment is under duress. </p>
<h2>Avoiding Hendra is easier than killing bats</h2>
<p>Pending release of a <a href="http://theconversation.com/hope-for-hendra-virus-vaccination-but-not-this-year-2143">vaccine against Hendra virus</a>, managing the immediate risk to horses and humans is simple – follow simple hygiene and feed management practices that reduce horse and horse feed exposure to bats and their excretions. </p>
<p>This is the approach recommended by Biosecurity Queensland and the <a href="http://www.qldhorsecouncil.com/QHC%20Documents/Notifiable%20Diseases%20Information%20Sheets/Hendra%20Virus%20-%20Reducing%20the%20Risk.pdf">Queensland Horse Council</a>. </p>
<p>This is because Hendra virus crosses to humans from infected horses, not from flying foxes, and the infection of horses takes place in the rural foraging range of the bats. </p>
<p>There is no incontrovertible evidence that harassing bats so colonies relocate increases rates of viral excretion. But the precautionary principle suggests the banging of drums, rattling of tins or roaring of engines is not a good idea. </p>
<p>Even if bat colonies do relocate, it is not clear how this will lower the exposure of horses in paddocks to flying foxes carrying Hendra virus. </p>
<p>Harassment and colony relocation has other limitations. Re-locating a bat colony is not easy: re-located bats often end up in places they are wanted even less. It is even less easy to be sure that when bats depart they do so as a result of the dispersal and not simply to follow the flowering of food trees. </p>
<p>Culling flying foxes is equally dubious. It is practically impossible to cull enough to reduce flying fox populations to a level acceptable to communities. If pursued, the risk of increased virus secretion as a result of stress is real and the public health benefit minimal. </p>
<h2>Ignoring science won’t cure disease</h2>
<p>Culling is cruel. <a href="http://www.hsi.org.au/editor/assets/Actions/FFreport4Jan09.pdf">Studies of bats</a> shot under permit in NSW orchards show that most died slowly. Many of those shot received debilitating wounds which resulted in death by starvation. This is not consonant with contemporary standards of humane treatment of animals. </p>
<p>And finally, removing animals that play key roles in the functioning of healthy ecosystems is certain to have wide-ranging but unquantifiable long-term effects on our agro-ecological support systems.</p>
<p>Some sections of the community are increasingly sceptical about scientific approaches to significant and contentious issues. Wilfully dumbing-down complex problems is a hallmark of this scepticism. </p>
<p>This attitude will continue to be a challenge to developing best practice biosecurity regimes in response to Hendra virus. More importantly, it may undermine our best efforts to deal with major drivers of disease emergence such as habitat loss.</p><img src="https://counter.theconversation.com/content/3253/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jon Luly does not work for, consult to, own shares in or receive funds from any entity which would benefit from this article. He has no affiliations which might give rise to a conflict of interest.</span></em></p><p class="fine-print"><em><span>Lee Francis Skerratt does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>This year has had the lot. First came the tempest, then the floods. Fires are on their way as the landscape dries out. Now we have pestilence, in the form of Hendra virus. Calls for bat culls have ensued…Jon Luly, Senior Lecturer in Physical Geography, James Cook UniversityLee Francis Skerratt, Senior Research Fellow, Tropical Infectious Diseases Research Centre , James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/23452011-07-15T04:35:39Z2011-07-15T04:35:39ZHold your horses: Hendra treatment is no panacea<figure><img src="https://images.theconversation.com/files/2317/original/aapone-20090811000198720403-hendra_virus_cawarral_qld-original.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Preventing infection with the Hendra virus remains the most effective measure against the virus.</span> <span class="attribution"><span class="source">AAP</span></span></figcaption></figure><p>Queensland authorities came <a href="http://www.theaustralian.com.au/national-affairs/hendra-virus-spreads-treatments-limited/story-fn59niix-1226094172689">under attack yesterday</a> for being unprepared for a Hendra virus outbreak after it was found that they’d only stocked 15 doses of virus antibodies. </p>
<p>But the case for stocking up is weak because treatment with these antibodies isn’t necessarily effective and its hard to predict the probability and severity of outbreaks.</p>
<p>Although Hendra virus has a high case-fatality ratio, only seven humans have been infected in 20 separate outbreaks since 1994. Four of those infected have died. </p>
<p>There is no proven treatment for the virus although the novel monoclonal antibody offers some hope. The only current treatment is supportive, which means patients must get a high level of attention in intensive care units.</p>
<p>Antiviral medications aren’t effective although experience is limited because of the recent discovery of the virus.</p>
<p>Antibodies are important for protection against and recovery from a range of viral infections. Human monoclonal antibodies specifically targeting different viruses have been developed for respiratory syncytial virus (RSV), Severe Acute Respiratory Syndrome-Associated coronavirus (SARS-CoV), Nipah and Hendra viruses. </p>
<p>But experimental evidence of the antibodies’ efficacy in fighting Hendra virus in animal studies is limited.</p>
<p>Part of the problem is that traditional animal models of mice, guinea pigs and rabbits are unsuitable for studying the virus as it doesn’t infect these animals.</p>
<p>Cats and golden hamsters are used instead, but data from these less well-studied animal models cannot always be extrapolated to humans. </p>
<p>Data from human clinical trials assessing the efficacy (and adverse effects) of Hendra virus monoclonal antibodies are unsurprisingly lacking given the extremely low incidence of infection. </p>
<p>So, what is the role of these monoclonal antibodies? Should they be given to everyone exposed to horses infected with Hendra virus or should they be reserved for patients confirmed as infected with the virus? </p>
<p>Essentially, monoclonal antibodies should be used judiciously – on a case-by-case basis – after a thorough risk assessment of the degree of exposure to sick horses, or the clinical features of the illness. </p>
<p>This tentative approach is particularly important because questions about dosage and optimal timing of administration remain unanswered. </p>
<p>Prevention of infection must remain the main focus of attention. Horses should be prevented from eating contaminated food, and sick horses should be isolated while awaiting confirmatory laboratory tests. </p>
<p>More importantly, standard hygiene practices should be strictly followed to prevent horse-to-human transmission. This applies particularly to veterinarians and horse owners. </p>
<p>The culling of flying foxes, which infect horses with the virus, is unlikely to contain a Hendra outbreak as: </p>
<ul>
<li><p>there’s a very large population of flying foxes; </p></li>
<li><p>all four species (grey-headed, black, spectacled and little-red) are potential reservoirs; </p></li>
<li><p>distressed flying foxes can excrete more virus; and </p></li>
<li><p>their ability to migrate could potentially transfer the problem to other parts of the country. </p></li>
</ul>
<p>A prototype vaccine developed by CSIRO has recently been shown to prevent infection in horses exposed to the virus. </p>
<p>This has the potential to break the animal-to-human transmission chain, preventing disease in animals and humans at the same time. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/2318/original/aapone-20110705000329685849-hendra_virus_outbreak_qld-original.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/2318/original/aapone-20110705000329685849-hendra_virus_outbreak_qld-original.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=409&fit=crop&dpr=1 600w, https://images.theconversation.com/files/2318/original/aapone-20110705000329685849-hendra_virus_outbreak_qld-original.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=409&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/2318/original/aapone-20110705000329685849-hendra_virus_outbreak_qld-original.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=409&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/2318/original/aapone-20110705000329685849-hendra_virus_outbreak_qld-original.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=514&fit=crop&dpr=1 754w, https://images.theconversation.com/files/2318/original/aapone-20110705000329685849-hendra_virus_outbreak_qld-original.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=514&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/2318/original/aapone-20110705000329685849-hendra_virus_outbreak_qld-original.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=514&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A vaccine being developed by CSIRO offers hope for containing future outbreaks.</span>
</figcaption>
</figure>
<h2>Anatomy of Hendra infection</h2>
<p>Hendra virus is a paramyxovirus native to Australia. It threatened to stop the Melbourne Cup in 1994, when thirteen horses and a horse-trainer died of a then unknown illness in the suburb of Hendra, approximately nine kilometres north-east of Brisbane. </p>
<p>It’s related to Nipah virus, which emerged in Malaysia in 1999 causing encephalitis in humans following widespread infection in pigs. </p>
<p>Flying foxes, common along the east coast of Australia, are the natural reservoir of Hendra virus, and human infection occurs with horses acting as intermediate hosts. </p>
<p>Horses are infected by exposure to food contaminated by the urine, saliva and birth by-products of flying foxes. There is no documented human-to-human transmission. </p>
<p>The incubation period of Hendra virus infection is 5 to 21 days, and it affects the respiratory and nervous systems. </p>
<p>The symptoms depend on the organs affected: similar to influenza (fever, cough, sore-throat, headache) when the lungs are involved and sometimes progressing to severe pneumonia; or meningitis/encephalitis (fever, headache, confusion) when there’s nervous system involvement. </p>
<p>Infection in horses produces a wide range of signs, including fever, restlessness, difficulty walking from poor balance and muscle twitching; and resulting in death within a few days. </p>
<p>Many research agendas about Hendra virus remain, including the investigation of the complex ecosystem of flying foxes; the lack of disease in other Australian states where flying foxes are prevalent; the virulence of the virus in different animal species; and the further development of animal and human vaccines and specific antiviral treatments.</p><img src="https://counter.theconversation.com/content/2345/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dominic Dwyer does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.</span></em></p><p class="fine-print"><em><span>Jen Kok does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations</span></em></p>Queensland authorities came under attack yesterday for being unprepared for a Hendra virus outbreak after it was found that they’d only stocked 15 doses of virus antibodies. But the case for stocking up…Dominic Dwyer, Director, Centre for Infectious Diseases and Microbiology Laboratory Services, Westmead Hospital, University of SydneyJen Kok, Research Fellow at the Centre for Infectious Diseases and Microbiology Laboratory Services, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/21432011-07-04T06:39:19Z2011-07-04T06:39:19ZHope for Hendra virus vaccination … but not this year<figure><img src="https://images.theconversation.com/files/2076/original/AAP_Hendra.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The vaccine – which will be given to horses – is currently 18 months away. </span> <span class="attribution"><span class="source">AAP</span></span></figcaption></figure><p>As Queensland authorities confirm the <a href="http://www.abc.net.au/local/stories/2011/07/04/3260213.htm">third outbreak</a> of <a href="http://theconversation.com/explainer-why-is-hendra-virus-so-dangerous-2083">Hendra virus</a> within a week, researchers are moving to fast track a horse vaccination for the deadly virus, which can spread from horses to humans and has killed four of the seven people infected in past outbreaks. </p>
<p>The vaccine has been in development for more than ten years, since shortly after the first outbreak of the disease was discovered in Hendra, Queensland.</p>
<p>Deborah Middleton, Senior Veterinary Pathologist at CSIRO’s Australian Animal Health Laboratory, explains how the vaccine will work:</p>
<p>When horses are vaccinated, they mount a protective response against the part of the Hendra virus particle that is important for binding the virus to body cells – this is the first stage of infection. </p>
<p>If the horse then comes into contact with Hendra virus, from the faeces and urine of flying-foxes, this protective response blocks the virus from infecting their body cells and allows their immune system to destroy it.</p>
<p><strong>When is the vaccine likely to be available?</strong></p>
<p>Our project plan currently aims to have the vaccine available in 2013, and this process has already been fast-tracked by getting a vaccine company involved earlier to formulate the vaccines for the research project. </p>
<p>We hope to speak with the regulatory authorities shortly to ensure we’ve exhausted all avenues for shortening the time it takes to get the product to market. </p>
<p>Although time is important, it’s equally important that we don’t cut short safety studies and other work that might influence the longer term success of the vaccine in the field.</p>
<p><strong>Do you expect it will be given to all horses or just those at increased risk?</strong></p>
<p>It’s likely that, in the first instance, vaccine uptake will be greatest in areas where there have been previous outbreaks of Hendra virus – eastern Queensland and north-eastern New South Wales. </p>
<p>But because there’s evidence that all flying-fox populations in Australia carry the virus, it’s possible that horse owners in other states may also wish to vaccinate their animals.</p>
<p><strong>Could the vaccine be adapted in future to be given to humans in close contact with horses?</strong></p>
<p>It’s theoretically possible that this could be done, but the registration pathway for getting a vaccine accepted for use in humans takes many years and it’s unlikely that it would be seen as a commercially-viable option. </p>
<p>Our strategy of targeting vaccination of horses is aimed at removing the immediate source of infection to people – the only humans affected by the disease are those in contact with horses sick from Hendra virus.</p>
<p><strong>Is there potential for your vaccine developments to assist in the development of a treatment for hendra virus?</strong></p>
<p>The vaccine work won’t directly contribute to research on treatment for people infected with Hendra virus, but we have, with our US colleagues, developed a post-exposure therapy targeting the same critical portion of the virus particle as the vaccine. </p>
<p>This therapy is available (on a case by case basis, as determined by Queensland Health) for people considered to be at high risk of contracting the infection, so those who have recently been exposed to an infected horse.</p>
<p><strong>Is Hendra virus isolated to Australia? Or do you expect this vaccination will be available internationally?</strong></p>
<p>Hendra virus is only found in Australia but it’s expected the vaccine would also provide protection against the closely related Nipah virus, which is found in Southeast Asia.</p>
<p><strong>Testing for Hendra virus can take several weeks, as we’re seeing with the eight exposed people in Queensland – why is this process so protracted?</strong></p>
<p>The incubation period of Hendra virus is up to several weeks, so testing needs to be carried out until it is certain that a person has not become infected. </p>
<p>Results of testing are generally available within 24hrs of the sample reaching the testing laboratory.</p>
<p><br> </p>
<p><em><strong>For more on the Hendra virus and what makes it so dangerous, read The Conversation’s <a href="http://theconversation.com/explainer-why-is-hendra-virus-so-dangerous-2083">Q&A with Dr Peter Daniels</a>, Assistant Director of the CSIRO’s Australian Animal Health Laboratory.</strong></em></p><img src="https://counter.theconversation.com/content/2143/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deborah Middleton 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>As Queensland authorities confirm the third outbreak of Hendra virus within a week, researchers are moving to fast track a horse vaccination for the deadly virus, which can spread from horses to humans…Deborah Middleton, Senior Veterinary Pathologist, CSIROLicensed as Creative Commons – attribution, no derivatives.