tag:theconversation.com,2011:/global/topics/bovine-tb-9109/articlesBovine TB – The Conversation2022-02-11T13:32:11Ztag:theconversation.com,2011:article/1739572022-02-11T13:32:11Z2022-02-11T13:32:11ZWhy badgers are unfairly demonised – and what we can do to help<figure><img src="https://images.theconversation.com/files/445777/original/file-20220210-63440-m65sif.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/european-badger-called-eurasian-part-controversial-220464949">Edward Hasting-Evans/shutterstock</a></span></figcaption></figure><p>Why can’t we leave badgers in peace? They are distinctive and iconic animals, but are subjected to shockingly high levels of abuse and <a href="https://www.wcl.org.uk/docs/WCL_Wildlife_Crime_Report_Nov_21.pdf">criminal behaviour</a>. Only very recently, a 28-year-old teaching assistant has been found guilty of animal cruelty after the RSPCA and police found pictures of her abhorrent <a href="https://www.dailymail.co.uk/news/article-10493251/Woman-encouraged-child-2-kill-badgers-foxes-faces-prison-animal-cruelty-offences.html">badger baiting</a> activities on a closed Facebook group. </p>
<p>Yet, with their trade mark black and white markings, large social groups and shy nature, badgers were very much part of British culture – they feature in classic children’s literature with characters such as Bill Badger, the best friend of Rupert the Bear, and kindly Mr Badger in Kenneth Grahame’s Wind in the Willows. They seem to have the unusual status of being one of the most loved British mammals in fiction, but one of the most persecuted in the real world.</p>
<h2>Badger cull impact</h2>
<p>Despite being the UK’s largest remaining carnivore, <a href="https://www.badgertrust.org.uk/badgers">badgers are omnivorous</a> and emerge from their setts – elaborate systems of tunnels and nest chambers – at night to hunt for earthworms (a large proportion of their diet) as well as insects, fruits, cereals and small mammals. </p>
<p>Inevitably, badgers do often wander through fields with cattle. And they also happen to be the unfortunate carriers of a bacteria <em>Mycobacterium bovis</em> which causes severe disease in cows. As bovine tuberculosis (bTB) can wipe out a farmer’s entire herd and livelihood, it led to the UK government sanctioning its controversial <a href="https://commonslibrary.parliament.uk/research-briefings/sn06837/">badger cull</a>, which has been responsible for the ongoing killing of thousands of the animals since 2013. </p>
<p>It is likely that badgers unwittingly <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/756942/tb-review-final-report-corrected.pdf">help to spread bovine TB</a> – but the evidence is unclear about how much culling actually helps to reduce the disease in cattle. In 2019, research found that it could in fact <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.13512">make things worse</a> by pushing badgers out into other areas where culling is not taking place.</p>
<p>Whatever the impact of the culls, there can be little doubt that they had an effect on public perception. </p>
<p>There was huge public support for badgers through organisations such as the <a href="https://www.mammal.org.uk/2016/05/badgers-and-bovine-tuberculosis/">Mammal Society</a> and the <a href="https://www.wildlifetrusts.org/wildlife-and-wild-places/saving-species/badgers/solution">Wildlife Trusts</a> who are opposed to the cull.</p>
<figure class="align-center ">
<img alt="Queen guitarist Brian May leads a Team Badger protest march mimicking a funeral parade, to mark the killing of 2,263 badgers in 2013/14." src="https://images.theconversation.com/files/445801/original/file-20220210-47270-4gm99j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/445801/original/file-20220210-47270-4gm99j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/445801/original/file-20220210-47270-4gm99j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/445801/original/file-20220210-47270-4gm99j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/445801/original/file-20220210-47270-4gm99j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=523&fit=crop&dpr=1 754w, https://images.theconversation.com/files/445801/original/file-20220210-47270-4gm99j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=523&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/445801/original/file-20220210-47270-4gm99j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=523&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">Badgers do have public support, including from high profile campaigners.</span>
<span class="attribution"><a class="source" href="https://www.alamy.com/stock-photo-badger-cull-protest-108380066.html?pv=1&stamp=2&imageid=9BE056C4-E7EF-413E-805B-B0C1EA2B19E7&p=309300&n=1&orientation=0&pn=1&searchtype=0&IsFromSearch=1&srch=foo%3Dbar%26st%3D0%26sortby%3D2%26qt%3Dbadger%2520cull%2520protest%26qt_raw%3Dbadger%2520cull%2520protest%26qn%3D%26lic%3D3%26edrf%3D0%26mr%3D0%26pr%3D0%26aoa%3D1%26creative%3D%26videos%3D%26nu%3D%26ccc%3D%26bespoke%3D%26apalib%3D%26ag%3D0%26hc%3D0%26et%3D0x000000000000000000000%26vp%3D0%26loc%3D0%26ot%3D0%26imgt%3D0%26dtfr%3D%26dtto%3D%26size%3D0xFF%26blackwhite%3D%26cutout%3D%26archive%3D1%26name%3D%26groupid%3D%26pseudoid%3D%7BAA4BFA21-6A20-4973-A795-CDDDB8962471%7D%26userid%3D%26id%3D%26a%3D%26xstx%3D0%26cbstore%3D1%26resultview%3DsortbyPopular%26lightbox%3D%26gname%3D%26gtype%3D%26apalic%3D%26tbar%3D1%26pc%3D%26simid%3D%26cap%3D1%26customgeoip%3DGB%26vd%3D0%26cid%3D%26pe%3D%26so%3D%26lb%3D%26pl%3D0%26plno%3D%26fi%3D0%26langcode%3Den%26upl%3D0%26cufr%3D%26cuto%3D%26howler%3D%26cvrem%3D0%26cvtype%3D0%26cvloc%3D0%26cl%3D0%26upfr%3D%26upto%3D%26primcat%3D%26seccat%3D%26cvcategory%3D*%26restriction%3D%26random%3D%26ispremium%3D1%26flip%3D0%26contributorqt%3D%26plgalleryno%3D%26plpublic%3D0%26viewaspublic%3D0%26isplcurate%3D0%26imageurl%3D%26saveQry%3D%26editorial%3D%26t%3D0%26filters%3D0">Jonathan Brady/PA Images/Alamy Stock Photo</a></span>
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<p>Some animal campaigners feared that they resulted in the <a href="https://www.theguardian.com/uk-news/2018/feb/05/huntsman-jailed-for-badger-baiting-in-wales">badger becoming “demonised”</a> in certain parts of the UK – and government policy was at least in part responsible for the increase in cruelty towards the animal through barbaric activities such as badger baiting. </p>
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Read more:
<a href="https://theconversation.com/badger-cull-alone-wont-work-for-eradicating-bovine-tb-but-this-might-107472">Badger cull alone won't work for eradicating bovine TB – but this might</a>
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<p>It didn’t stop there. Although the badger cull itself is legal, it has been used as a front by some criminals in order to make money. One licensed badger cull contractor, for example, <a href="https://www.bbc.co.uk/news/uk-england-cornwall-50335647">illegally killed 28 badgers</a> outside of the cull period and then stored the bodies in a freezer in order to claim payment when the cull window was reopened.</p>
<h2>Unsubstantiated perceptions don’t help</h2>
<p>Badgers have also been <a href="https://www.mdpi.com/2076-2615/9/10/759">implicated in the decline</a> of the hedgehog, ‘<a href="https://www.rsb.org.uk/news/hedgehog-wins-favourite-uk-mammal-poll#:%7E:text=The%20hedgehog%20has%20been%20voted,in%20second%20place%20with%2015.4%25">UK’s favourite mammal</a>’. </p>
<p>While it is true that badgers are the main wild predator of hedgehogs and a competitor for food, the two species currently coexist in many areas of England and Wales, with one study reporting badger presence at <a href="https://www.nature.com/articles/s41598-018-30130-4">49% of sites</a> where hedgehogs were found. </p>
<p>And although <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0095477#:%7E:text=By%20the%20end%20of%20culling,were%20culled%20(Figure%201)">hedgehog numbers</a> have been reported to increase in badger cull areas, hedgehog numbers have declined <a href="https://www.mdpi.com/2076-2615/10/9/1566">all over the UK</a>, including in regions <a href="https://ptes.org/wp-content/uploads/2014/06/SOBH2011lowres.pdf">with fewer badgers</a> than the cull areas.</p>
<p>This suggests that while badgers may have some negative impact on hedgehogs as you’d expect with any predator-prey relationship, there is no clear connection between declining hedgehog numbers and the size of the badger population - and it’s important to remember that they have co-existed for thousands of years without human interference in the form of culls. </p>
<p>In fact, a <a href="https://ptes.org/state-britains-hedgehogs-report-2018/">report on hedgehog declines</a> found that habitat loss through the intensification of agriculture, fewer hedgerows and tidier gardens are the main drivers. </p>
<p>Badgers are also perceived to be responsible for the decline of ground nesting birds, with a recent survey by the Game and Wildlife Conservation Trust (GWCT) showing that <a href="https://www.gwct.org.uk/blogs/news/2021/june/badger-predation-%E2%80%93-it%E2%80%99s-not-all-black-and-white-(part-1)">75% of respondents</a> believe this to be true. But a recent study looking at bird populations inside and outside badger cull areas in South-West England found <a href="https://www.tandfonline.com/doi/full/10.1080/00063657.2021.1889460">no evidence</a> that the removal of badgers made any difference.</p>
<h2>What can be done?</h2>
<p>To its credit, the National Trust has already <a href="https://www.nationaltrust.org.uk/features/our-view-on-badgers-and-bovine-tb">banned badger culls</a> on its land. </p>
<p>And, crucially, in May 2021 the <a href="https://www.gov.uk/government/news/government-sets-out-next-phase-of-strategy-to-combat-bovine-tuberculosis-in-england">government announced</a> that the licensing of new intensive badger culls will stop at the end of 2022. Instead, they plan to focus their efforts on badger vaccination, increased cattle testing and development of cattle vaccines. </p>
<p>But despite this announcement, Natural England has approved <a href="https://www.bbc.co.uk/news/uk-england-58487796">seven new cull zones</a> and 40 new licences which allow the killing of tens of thousands of badgers by 2025. Much more needs to be done to challenge the perception among the farming community that culling badgers is the answer to eradicating bovine TB.</p>
<figure class="align-center ">
<img alt="European badger with trout caught in mouth in mountain stream" src="https://images.theconversation.com/files/445803/original/file-20220210-24693-1dbisd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/445803/original/file-20220210-24693-1dbisd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/445803/original/file-20220210-24693-1dbisd7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/445803/original/file-20220210-24693-1dbisd7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/445803/original/file-20220210-24693-1dbisd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/445803/original/file-20220210-24693-1dbisd7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/445803/original/file-20220210-24693-1dbisd7.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">Badgers are omnivores, but largely feast on earthworms, insects and small mammals.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/european-badger-meles-fishing-mountain-stream-1457752076">Martin Mecnarowski/shutterstock</a></span>
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</figure>
<p>As badgers are already fully protected by law – under the <a href="https://www.legislation.gov.uk/ukpga/1992/51/contents">Protection of Badgers Act 1992</a> – the key to reducing persecution lies in ensuring perpetrators are caught and convicted. This requires increasing public awareness and recognition of wildlife crimes. The Badger Trust has produced a <a href="https://www.youtube.com/watch?v=PtlMpg5Gl-A">short film</a> to show the different methods of badger persecution, how to recognise the signs and to highlight the importance of recording and reporting badger crimes.</p>
<p>As for hedgehogs, we can look closer to home when it comes to taking action. </p>
<p>Good habitat cover provides safety and refuge for hedgehogs, and in areas where food supply is plentiful, enables them to <a href="https://www.mdpi.com/2076-2615/10/9/1566">live alongside badgers</a>. Creating hedgehog friendly gardens by leaving wild areas and enabling connectivity to other gardens – by installing <a href="https://www.hedgehogstreet.org/help-hedgehogs/link-your-garden/">hedgehog highways </a> – has been found to <a href="https://ptes.org/success-stories/investigating-the-effectiveness-of-hedgehog-highways/">significantly increase sightings of hedghogs</a>. </p>
<p>In short, there is no reason why both of these popular animals can’t continue to coexist and thrive. And in any case, can it ever be right to demonise (and even kill) an animal for simply living its life?</p><img src="https://counter.theconversation.com/content/173957/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Anna Champneys 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>Badgers are shy and nocturnal animals. It’s time to challenge false perceptions and end the cruelty towards this iconic mammal.Anna Champneys, Senior Lecturer in Wildlife Conservation, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1733402021-12-07T14:59:01Z2021-12-07T14:59:01ZHyenas’ unpicky feeding habits help clean up a town in Ethiopia<figure><img src="https://images.theconversation.com/files/436084/original/file-20211207-19-kknfvt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">shutterstock</span> </figcaption></figure><p>Hyenas aren’t the most popular animals. Sometimes they kill people’s livestock. They are also thought of as scavengers, with some unappealing eating behaviour. Then there’s their cackling “laugh” and their physical looks, less graceful in some eyes than other large predators like lions or leopards. </p>
<p>But there’s a more positive side to these often misunderstood creatures. In Mekelle, a town in northern Ethiopia, <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.14024">research</a> has exposed and quantified the economic and health benefits that spotted hyenas bring to the community. Every year, they consume over 200 tons of waste in and around Mekelle. </p>
<p>The research also ran some disease transmission models. It found that by eating discarded carcasses, the hyenas are reducing the potential spread of diseases like anthrax and bovine tuberculosis. That’s a service to people and other animals, and saves some disease treatment and control costs.</p>
<p>In today’s episode of Pasha, biology student Chinmay Sonawane and wildlife conservation researcher Neil Carter take us through their findings on the benefits that spotted hyenas provide to the people of Mekelle.</p>
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<p><strong>Photo</strong>
“Spotted hyena (Crocuta crocuta), also known as the laughing hyena.” Photo by Vladimir Wrangel found on <a href="https://www.shutterstock.com/image-photo/spotted-hyena-crocuta-known-laughing-1177808107">Shutterstock.</a></p>
<p><strong>Music:</strong>
“Happy African Village” by John Bartmann, found on <a href="http://freemusicarchive.org/music/John_Bartmann/Public_Domain_Soundtrack_Music_Album_One/happy-african-village">FreeMusicArchive.org</a> licensed under <a href="https://creativecommons.org/publicdomain/zero/1.0/">CC0 1</a>.</p>
<p>“Ambient guitar X1 - Loop mode” by frankum, found on <a href="https://freesound.org/people/frankum/sounds/393520/">Freesound</a> licensed under <a href="http://creativecommons.org/licenses/by/3.0/">Attribution License.</a></p><img src="https://counter.theconversation.com/content/173340/count.gif" alt="The Conversation" width="1" height="1" />
Spotted hyenas provide ecosystem services that improve human welfare and contribute to sustainable development goals.Ozayr Patel, Digital EditorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1661972021-08-16T15:50:48Z2021-08-16T15:50:48ZGeronimo the alpaca – the case for animals having the same legal rights as people<p>The fate of Geronimo the alpaca was seemingly sealed in the UK’s high court <a href="https://www.bbc.co.uk/news/uk-england-gloucestershire-57997877">recently</a> when the appeal against an order to slaughter him was rejected. </p>
<p>After twice testing positive for bovine tuberculosis (TB), Geronimo’s death was ordered by the Department for Environment, Food and Rural Affairs (Defra) back in 2017, with that order upheld in the latest high-court decision. A legal challenge by Helen Macdonald, Geronimo’s owner, had delayed the implementation of the order, and <a href="https://www.dailymail.co.uk/news/article-9892651/Geronimo-alpaca-receives-72-hour-stay-execution.html">further legal proceedings</a> have granted <a href="https://www.bbc.co.uk/news/uk-england-gloucestershire-58241387">another stay of execution</a> ahead of a review.</p>
<p>Given that <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/994066/bovinetb-statsnotice-Q1-quarterly-16jun21.pdf">tens of thousands</a> of animals are slaughtered each year in England and Wales to control the spread of bovine TB, it’s worth asking why Geronimo’s case in particular has attracted <a href="https://www.nytimes.com/2021/08/10/world/europe/geronimo-alpaca-execution-.html">global media attention</a>. The answer is that Macdonald has taken the matter to the courts on multiple occasions. But the very fact that the litigation
is in <a href="https://www.bailii.org/cgi-bin/format.cgi?doc=/ew/cases/EWHC/Admin/2019/1783.html&query=(title:(+macdonald+))">her name</a> and not Geronimo’s highlights how the the definition of legal personhood restricts the rights of animals under the law.</p>
<h2>Non-humans as legal persons</h2>
<p>Legal personhood is a crucial part of any legal system, as only those who are recognised as a person by the law can enforce their legal rights. If animals had their own rights as legal persons, entities other than owners could enforce them, such as anti-cruelty campaigners asking a court to uphold the rights of animals kept in inhumane conditions. The protections and remedies the law provides would be for the benefit of the animal, not its owner.</p>
<p>Personhood is an artificial categorisation that is by no means restricted to human beings – companies and ships are among entities which have been recognised as legal persons in the past. Academics are <a href="http://www.environmentandsociety.org/mml/should-trees-have-standing-law-morality-and-environment">now debating</a> whether legal personhood should be extended to other natural entities besides humans, with some <a href="https://www.jurist.org/commentary/2020/04/sanket-khandelwal-environment-person/">notable successes</a>. Personhood has even been bestowed on environmental features, such as <a href="https://theconversation.com/rights-for-nature-how-granting-a-river-personhood-could-help-protect-it-157117">Muteshekau Shipu</a>, a river in Quebec that was declared a legal person in February 2021, with nine particular legal rights including the right to “<a href="https://www.aljazeera.com/news/2021/4/3/this-river-in-canada-now-legal-person">live, exist and flow</a>”.</p>
<p>But instances of courts recognising the legal personhood of animals are still <a href="https://theconversation.com/happy-the-elephant-was-denied-rights-designed-for-humans-but-the-legal-definition-of-person-is-still-evolving-152410">few and far between</a>. This means that animals are still considered property in most jurisdictions, including the UK, reducing them to the <a href="https://www.peta.org/teachkind/lesson-plans-activities/nouns-animals-not-things/">status of things</a>: objects to which the law is applied, rather than subjects of the law who possess their own legal rights. </p>
<p>Chimpanzees are <a href="https://www.smh.com.au/technology/when-will-my-child-outsmart-a-chimp-not-until-theyre-4-or-more-scientists-say-20170619-gwtycu.html">intellectually comparable</a> to a four-year-old, but a chimp is legally comparable to a chocolate bar, not a child. The high court was not asked to decide on whether Geronimo had a legal right to life. It was asked to decide whether Defra had acted irrationally in ordering the destruction of Macdonald’s property.</p>
<p>Given that legal personhood is <a href="https://www.nationalaffairs.com/publications/detail/are-corporations-people">already bestowed</a> on non-human entities, there is no technical reason to withhold it from animals. In fact, bestowing personhood on animals could provide a lasting benefit for animal rights. After all, for legal rights to be meaningful, they must be enforceable. And to enforce one’s rights in a court of law, one must be recognised by that court. <a href="https://www.ted.com/speakers/steven_wise">Steven M Wise</a>, one of the most influential legal scholars writing on animal rights, <a href="https://www.animallaw.info/sites/default/files/lralvol17_1_1.pdf">has argued</a> that legal personhood is synonymous with the capacity to possess rights, and so personhood becomes a basic prerequisite for meaningful legal rights for animals.</p>
<p>As Geronimo’s story has shown, when animals are considered as individuals rather than an indeterminate mass, our perceptions of fair treatment shift dramatically. Some have argued that the public outcry is because Geronimo is “<a href="https://www.thetimes.co.uk/article/alpaca-owners-must-accept-slaughter-is-a-necessary-evil-rzp5637vv">irresistibly cute</a>”. They may well be right, but perhaps it is not that Geronimo is cute as much as Geronimo is an individual with a name and a face. As the <a href="https://quoteinvestigator.com/2010/05/21/death-statistic/">famous saying</a> goes, “a single death is a tragedy, a million deaths is a statistic”.</p>
<p>The definition of a legal person is also becoming blurred in another way. Legal personhood for artificial intelligence (AI) is a hot topic not just in <a href="https://doi.org/10.1017/S0020589320000366">academic literature</a>, but in the <a href="https://www.supremecourt.uk/docs/speech-190314.pdf">speeches</a> of <a href="https://www.supremecourt.uk/docs/speech-191112.pdf">justices</a> of the US supreme court and in the <a href="https://europeanlawblog.eu/2020/11/25/refusing-to-award-legal-personality-to-ai-why-the-european-parliament-got-it-wrong/">European parliament</a>.</p>
<p>Artificial intelligence is already entering contracts, operating vehicles and making decisions that affect the legal rights of humans. Should AI in these positions not bear legal responsibility? The more <a href="https://ai-regulation.com/refusing-to-award-legal-personality-to-ai-why-the-european-parliament-got-it-wrong/">involved</a> we are with AI, the more a legal identity for that AI is needed. To have meaningful rights in our legal landscape, you must have legal personhood. In this case, it might make it possible for an AI to own the intellectual property it creates, for example. </p>
<p>Geronimo’s fate will be decided long before any such changes take effect. Thanks to his owner’s concern, Geronimo has at least had his day in court. It is time to seriously consider whether that is a right we should extend to other sentient beings.</p><img src="https://counter.theconversation.com/content/166197/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fred Motson 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>Boats and companies have been treated as legal persons in the past. Why not an alpaca?Fred Motson, Lecturer in Law, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1313262020-02-10T17:01:59Z2020-02-10T17:01:59ZHS2 debate shows how evidence is ignored in favour of politics<p>The British government is <a href="https://www.bbc.co.uk/news/business-51443421">expected to reaffirm</a> its commitment to building HS2, the proposed high-speed rail network, despite substantial opposition from sections of the public, politicians and environmental groups. For example, a <a href="http://stophs2.org/wp-content/uploads/2020/01/Whats-the-damage-Summary-Report-FINAL-digital.pdf">recent report</a> commissioned and published by <a href="https://www.wildlifetrusts.org/about-us">The Wildlife Trusts</a> drew attention to the habitat loss threatened by HS2. The report claims as many as 693 classified wildlife sites within 500 metres of the line will be impacted, something echoed by <a href="https://rebellion.earth/event/extinction-rebellion-save-colne-valley-from-hs2/">Extinction Rebellion</a> and <a href="http://stophs2.org/">Stop HS2</a> activists:</p>
<blockquote>
<p>Using guile, deceit, lies, fraud, coercion, blackmail and immensely destructive practices, HS2 wish to put an end to all we hold dear and our most important legacy to our children. This is our rainforest. Right now we desperately need tree climbers. We desperately need people. People really scare HS2.</p>
</blockquote>
<p>This emotive language, playing to historic fears of destruction, pits HS2 against conservation. The pressure from environmental groups adds to that <a href="https://inews.co.uk/news/politics/tory-mps-mutiny-boris-johnson-hs2-decision-trains-1380728">from those politicians</a> who want the government to cancel or alter the project in favour of schemes that provide more benefit to their local areas. As a result, the future of the scheme has been uncertain, even with government backing.</p>
<p>Yet, like many projects with importance for wildlife, HS2 is by no means a clear-cut choice between obliteration and preservation. The problem is that human politics is central in defining the outcome of such planned projects and scientific knowledge is too often displaced by binary thinking.</p>
<p>The purpose of HS2 is partly to provide faster rail services between London, Birmingham, Manchester and Leeds (and, in turn, to other follow-on destinations). But it will also increase capacity on existing rail routes by taking current fast intercity trains off those lines, making space for more local commuter and freight services.</p>
<p>Research by the transport development organisation <a href="https://www.midlandsconnect.uk/publications/hs2-released-capacity/">Midlands Connect</a> found that as many as 73 stations would benefit from increased rail capacity, 54 of which are not directly served by the new lines. In short, HS2 will streamline a large proportion of the UK’s rail network.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/314470/original/file-20200210-109896-138lfjt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/314470/original/file-20200210-109896-138lfjt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=362&fit=crop&dpr=1 600w, https://images.theconversation.com/files/314470/original/file-20200210-109896-138lfjt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=362&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/314470/original/file-20200210-109896-138lfjt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=362&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/314470/original/file-20200210-109896-138lfjt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=455&fit=crop&dpr=1 754w, https://images.theconversation.com/files/314470/original/file-20200210-109896-138lfjt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=455&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/314470/original/file-20200210-109896-138lfjt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=455&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Siemens’ proposed design for HS2 trains.</span>
<span class="attribution"><a class="source" href="https://news.siemens.co.uk/news/siemens-mobility-formally-submits-bid-for-hs2-contract">Siemens</a></span>
</figcaption>
</figure>
<p>The provision of frequent, accessible and attractive public transport is needed to encourage a “modal shift” away from the country’s reliance on CO₂-producing cars, lorries and planes. HS2 offers the UK a major opportunity to follow the examples demonstrated elsewhere <a href="https://ec.europa.eu/jrc/en/publication/passenger-aviation-and-high-speed-rail-comparison-emissions-profiles-selected-european-routes">in Europe</a> <a href="https://www.iea.org/reports/the-future-of-rail">and Asia</a>. High-speed rail has reduced air travel’s modal share <a href="https://www.tandfonline.com/doi/pdf/10.1080/01441647.2013.853707">everywhere it has been introduced</a> and can also reduce car use, especially over long distances, helping to create a new vision for long-distance travel. </p>
<p>Without this kind of change, we face runaway climate change and a significant threat <a href="https://blogs.ei.columbia.edu/2018/01/15/biodiversity-climate-change/">to exactly the biodiversity</a> that environmental groups want to protect – and not just in the area around HS2’s tracks. <a href="https://www.nature.com/articles/s41467-019-13241-y">Research has shown</a> how overall biodiversity can benefit even from measures to address climate change that might damage it on a small scale.</p>
<p>Yet the research is too often overlooked when political debates descend into simplistic narratives of development versus destruction, preservation versus loss. The picture is always more complex.</p>
<h2>Badger culling</h2>
<p>HS2 is not an isolated example of politics taking precedence over evidence. Take, for instance, the UK government’s current strategy for eradicating bovine tuberculosis, which involves the culling of infected cattle and, in some regions, other species that can spread the disease, <a href="https://www.theguardian.com/environment/2019/sep/11/badger-cull-england-extended">such as badgers</a>.</p>
<p>The government describes this approach as <a href="https://www.gov.uk/government/publications/bovine-tb-eradication-programme-for-england">“science-led”</a>. Yet as with HS2, the whole picture is complex and coloured by politics. While culling might seem a good solution, and is popular with practitioners, it is only fair to say that the scientific evidence <a href="https://www.nature.com/articles/s41598-019-49957-6">shows a mixed picture</a>. </p>
<p>Many <a href="https://www.peta.org.uk/blog/badger-cull-3656-animals-killed-no-proven-disease-control-benefits/">environmental activists argue</a> that the limited evidence for culling means the animals suffer needlessly. On the other hand, in some places the culling of badgers can have a <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0095477">positive impact</a> on species they prey on, such as hedgehogs.</p>
<p>As for cattle, the <a href="https://www.nhs.uk/news/food-and-diet/is-eating-meat-infected-with-bovine-tb-harmful/">government itself recognises</a> that the risks of people catching TB from milk or meat from infected cows are extremely low. But because of restrictions in other countries, bovine TB impacts the UK’s ability to sell its produce abroad, which is increasingly important following Brexit and the opening of new trade negotiations around the world.</p>
<p>In a climate where politicians and commentators polarise the debate, members of the public can find it understandably difficult to judge the worth of various policies that impact wildlife. And the <a href="https://www.ft.com/content/3be49734-29cb-11e6-83e4-abc22d5d108c">rejection of expert</a> and practitioner knowledge also makes it difficult for policy-makers to make pragmatic judgements. </p>
<p>What we actually need is more, not less, scientific knowledge. Politicians, activists, journalists and the general public need to take a closer look at the empirical and scientific evidence to make a balanced judgement when evaluating difficult ecological problems that arise in the wake of infrastructure planning. Now more than ever, we need to move beyond human politics to investigate the facts that support sustainable policy decisions.</p><img src="https://counter.theconversation.com/content/131326/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 new railway might destroy some wildlife habitats but what if it helps tackle climate change?Lindsay Hamilton, Senior Lecturer in Organisational Ethnography, University of YorkKevin Tennent, Senior Lecturer in Management, University of YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/961372019-03-06T14:40:29Z2019-03-06T14:40:29ZWhy warthogs are useful in figuring out how bovine TB spreads<figure><img src="https://images.theconversation.com/files/262193/original/file-20190305-48417-1gl07c2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Warthogs are believed to be potential hosts of bovine TB. </span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Tuberculosis is not just a human disease. Cattle also contract a similar type of bacteria, called bovine tuberculosis. Evidence suggests that it can be <a href="https://www.ncbi.nlm.nih.gov/pubmed/23587372">transmitted</a> from cattle to humans as well as wildlife and vice versa.</p>
<p>Bovine tuberculosis has been well studied <a href="https://www.tbfacts.org/bovine-tb/">in cattle</a>. This is particularly true in Europe where the disease was very prevalent during the 19th and 20th centuries. It’s estimated that the agricultural sector, globally, has a total loss of more than <a href="https://www.pnas.org/content/100/13/7877">US$3 billion annually</a> due to bovine tuberculosis. In the UK more than 39 000 cattle were slaughtered after testing positive for the disease <a href="https://researchbriefings.parliament.uk/ResearchBriefing/Summary/SN06081">in 2016</a>.</p>
<p>The disease made its way into Africa during the 18th and 19th centuries through the importation of cattle from the <a href="http://www.sun.ac.za/english/Inaugurallectures/Inaugural%20lectures/InauguralLectureProfMiller.pdf">UK, Europe and Australia</a>. Now wildlife, like lions and wild dogs which prey on potentially infected animals, such as buffalo and warthogs, have also become infected.</p>
<p>But only a few studies have investigated the effect its had on Africa’s wildlife populations. This is starting to change, as the disease’s impact on vulnerable and endangered species like <a href="https://africageographic.com/blog/more-than-half-of-southern-krugers-lions-may-have-tb/">lion</a>, <a href="https://www.pressreader.com/south-africa/the-mercury/20160920/281659664511702">rhino</a> and <a href="https://www.frontiersin.org/articles/10.3389/fvets.2019.00018/full">elephants with human TB</a> are coming under the spotlight. </p>
<p>Lions potentially become infected through eating infected animals and rhino may become infected through environmental spillover, when sharing their grazing with infected animals such as buffalo. </p>
<p>There’s also a new focus on the disease and warthogs, animals that are believed to be potential hosts of <a href="https://nationalzoo.si.edu/animals/news/case-warthog-disease">bovine TB</a>. I set out to study the role these tusked mammals play when it comes to <a href="http://doi.wiley.com/10.1111/tbed.12856">disease prevalence</a> and to find out their susceptibility to bovine TB. </p>
<p>I found that warthogs have a high disease prevalence in bovine TB endemic regions and that they are susceptible to the disease in the wild. This is important information that will help us to develop effective disease management strategies to reduce and control the spread of bovine TB in South Africa. </p>
<h2>Why warthogs?</h2>
<p>Putting a number to the warthog population size in South Africa is difficult, but the estimate in 2016 was 22 250. This number means that they aren’t in any way <a href="http://www.iucnredlist.org/details/41768/0">threatened</a>. It also means, they’re an important species when it comes to studying infectious diseases such as bovine TB. </p>
<p>Warthogs are also useful in studying the dynamics of this disease as they’re free-roaming. This means that they aren’t kept in by barriers, like fences, and can move freely between parks, reserves and farm land. This potentially increases their chances of contact with livestock and humans. </p>
<p>To begin my research I first had to be able to accurately determine which individuals were infected and which ones weren’t. I did this by evaluating tests that were developed for other species and then optimised and modified them to develop new diagnostic tests for warthogs. An example was the Quantiferon assay used in humans that we modified to be <a href="https://www.sciencedirect.com/science/article/pii/S0165242718300916">used in warthogs</a>.</p>
<p>One of my newly <a href="https://www.sciencedirect.com/science/article/pii/S0165242716302136">developed tests</a> was used to investigate the disease prevalence from historically banked warthog samples. This allowed me to study the extent of the disease in warthog populations. Thus allowing the description of some key risk factors of the disease in warthogs.</p>
<p>The <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/tbed.12856">high prevalence</a> of the disease, in some cases higher than 60%, suggests that warthogs are either prone to infection through contact with other infected species, or that they are spreading the disease within their own populations. </p>
<p>My research suggests that the answer is probably something in between the two scenarios. This is because warthogs are frequently seen scavenging on carcasses of other animals, such as buffalo, which are a potential source of infection. In addition, their burrowing behaviour allows for close contact between individuals in a confined spaces which increases the risk of transmission. I have, however, not been able to show yet that warthogs secrete (spread) the disease in to their ecosystem.</p>
<p>I also found that <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/tbed.12856">adult warthogs were at a higher risk</a> of having the disease, than either sub-adults or juveniles. There are two possibilities for this: </p>
<p>1) adults have been exposed for a longer period of time; or,</p>
<p>2) younger individuals may die before being tested.</p>
<p>Both these scenarios could increase the risk of spreading the disease to other species indirectly. On the one hand there’s a greater chance of an animal spreading the disease if they have it for a long time. On the other if they succumb to the infection as juveniles, scavengers may become infected who ingest the infected carcass.</p>
<h2>Understanding and implications</h2>
<p>A deeper dive into the information we’d gathered showed us that warthogs can be used as disease sentinels. Sentinel species are used to monitor the spread of a disease, and its presence or absence. Using sentinels is useful because it means that we don’t need to resort to testing valuable or endangered animals which can be risky.</p>
<p>Warthogs are a perfect sentinel species for a number of reasons. There are lots of them, they’re highly susceptible, they survive the disease and with the help of my new test, have easily detectable signs of infection. </p>
<p>This means that warthogs are an important species in managing the disease. </p>
<p>The next steps will be to determine whether warthogs transmit the disease to other species or does transmission stop at an individual level.</p><img src="https://counter.theconversation.com/content/96137/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eduard Roos received funding from the South African Medical Research Council as well as the National Research Foundation of South Africa, SARChI Animal TB grant and Scarce Skills bursary during this study. The content is the sole responsibility of the author and does not necessarily represent the official views of the funders. </span></em></p>Warthogs are an important species in managing bovine TB.Eduard Roos, Postdoctoral Scientist, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1074722018-12-06T13:55:10Z2018-12-06T13:55:10ZBadger cull alone won’t work for eradicating bovine TB – but this might<figure><img src="https://images.theconversation.com/files/248721/original/file-20181204-34138-n64a35.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:M%C3%A4yr%C3%A4_%C3%84ht%C3%A4ri_4.jpg">Kallerna/Wikimedia Commons.</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Controlling the epidemic of tuberculosis in English cattle is a hugely controversial issue. The role badgers play in that epidemic and how to prevent their infection spreading to cattle is also hotly contested. </p>
<p>The recent <a href="https://www.gov.uk/government/publications/a-strategy-for-achieving-bovine-tuberculosis-free-status-for-england-2018-review">Bovine TB Strategy Review</a>, known as the “Godfray Review”, described culling badgers as having only a “relatively modest benefit” in reducing the incidence of TB in cattle and described the use of “non-lethal” control of infection in badgers as “highly desirable”. </p>
<p>Culling badgers has been <a href="https://yougov.co.uk/topics/politics/articles-reports/2014/09/11/two-years-badger-cull-remains-unpopular">largely unpopular</a> with the public, and since the report suggests it may not be an effective long-term solution, what are the non-lethal alternatives, and do they work? </p>
<p>There are three main approaches to reducing the risk that TB in badgers poses to cattle. We can reduce the number of badgers, reduce contact between badgers and cattle, or reduce infection among badgers. </p>
<h2>Culling or birth control for badgers?</h2>
<p>The idea behind culling is simply to reduce badger numbers so that the amount of badger-to-badger and badger-to-cattle transmission falls, ideally until the infection dies out among the badgers. </p>
<p>The largest trial of badger culling, the <a href="https://webarchive.nationalarchives.gov.uk/20081108133322/http:/www.defra.gov.uk/animalh/tb/isg/pdf/final_report.pdf">Randomised Badger Culling Trial</a>, finished around ten years ago and found that culling caused both a reduction in badger numbers and of TB in cattle.</p>
<p>But it also found that a high proportion of the <a href="http://www.pnas.org/content/103/40/14713.long">remaining badgers had TB</a>. So once culling stops, a regrowing badger population that’s still infected might pose an even greater risk to cattle.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/badger-cull-didnt-kill-enough-badgers-to-be-effective-36388">Badger cull didn't kill enough badgers to be effective</a>
</strong>
</em>
</p>
<hr>
<p>Early trials have suggested another way to <a href="http://sciencesearch.defra.gov.uk/Default.aspx?Menu=Menu&Module=More&Location=None&Completed=0&ProjectID=17952">reduce badger populations</a>: immunocontraception. This involves vaccinating badgers against their own reproductive hormones so they can’t get pregnant. It may prove more socially acceptable than culling. </p>
<p>But rolling this out is some way off. As it reduces the future birth rate rather than increasing the death rate, contraception will also take longer to reduce badger populations than culling. </p>
<h2>Biosecurity</h2>
<p>Keeping cattle and badgers apart with physical barriers around farm buildings such as badger-proof gates and electric fences – an approach <a href="http://www.tbhub.co.uk/biosecurity/biosecurity-guidance-farm-buildings/">known as “biosecurity”</a> – is relatively simple but can be expensive. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/248745/original/file-20181204-34142-lmqvyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/248745/original/file-20181204-34142-lmqvyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/248745/original/file-20181204-34142-lmqvyi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/248745/original/file-20181204-34142-lmqvyi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/248745/original/file-20181204-34142-lmqvyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/248745/original/file-20181204-34142-lmqvyi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/248745/original/file-20181204-34142-lmqvyi.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">Biosecurity – keeping cattle and badgers separate – could be part of the solution.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/wildlife-protection-fence-return-facility-keep-534795562?src=8hzYRllp_2GUlfzjqAh_DQ-1-27">Rudmer Zwerver/Shutterstock</a></span>
</figcaption>
</figure>
<p>How the disease is transmitted in open environments, through slurry and soil movement or on contaminated farm vehicles, people and wildlife, is less well understood.</p>
<p>However, improved biosecurity will also help control other infectious diseases. The <a href="http://www.tbas.org.uk/">TB Advisory Service</a>, which provides free advice to farmers, emphasises integrating TB and other disease control programmes.</p>
<h2>Vaccination</h2>
<p>Badger vaccination requires first trapping the badgers, as it uses the same injectable vaccine, BCG, as is used in humans. It is undertaken by <a href="https://www.gov.uk/government/publications/badger-edge-vaccination-scheme-2-bevs-2/how-to-run-a-scheme-to-vaccinate-badgers">trained and licensed</a> volunteers in England, thereby reducing the cost. </p>
<p>Oral vaccines would be easier to use but are not yet licensed. Small numbers of <a href="https://www.gov.uk/government/publications/2010-to-2015-government-policy-bovine-tuberculosis-bovine-tb/2010-to-2015-government-policy-bovine-tuberculosis-bovine-tb#appendix-5-badger-vaccination">trials have demonstrated</a> that vaccination reduces both the number of badgers infected and the degree of disease in badgers with only partial protection. However, unlike for culling, there have been no large-scale trials of the effect that vaccinating badgers has on TB in cattle.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/248713/original/file-20181204-34122-1d3tilz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/248713/original/file-20181204-34122-1d3tilz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/248713/original/file-20181204-34122-1d3tilz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/248713/original/file-20181204-34122-1d3tilz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/248713/original/file-20181204-34122-1d3tilz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/248713/original/file-20181204-34122-1d3tilz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/248713/original/file-20181204-34122-1d3tilz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A badger is caught and vaccinated by a trained specialist.</span>
<span class="attribution"><span class="source">Jason Skeen/Derbyshire Wildlife Trust</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Most badger vaccination in England has been undertaken in areas <a href="https://www.gov.uk/government/news/badger-vaccination-scheme-relaunched-in-fight-against-bovine-tb">in front of the expanding cattle epidemic</a>, where the badgers are believed to be free of bovine TB. This is because vaccination will protect against infection in susceptible badgers but will not stop the development of the disease in those already infected. But vaccination may still be effective at the population level among infected badgers by reducing transmission. </p>
<p>A <a href="https://doi.org/10.1016/j.prevetmed.2017.10.010">recent study in Ireland</a> found that vaccination reduced transmission enough that TB should die out among the badgers if reinfection from cattle is prevented. It will be interesting to see if vaccination on the edge of the English cattle epidemic has any effect on the expansion of the epidemic in either cattle or badgers. Determining this, however, will require <a href="https://www.gov.uk/government/publications/a-strategy-for-achieving-bovine-tuberculosis-free-status-for-england-2018-review">more surveillance of TB in badgers</a> than at present.</p>
<h2>Combined solutions</h2>
<p>In Ireland, the follow-up strategy to culling badgers appears to be <a href="https://www.agriculture.gov.ie/press/pressreleases/2018/january/title,113880,en.html">vaccination</a>, while a “test-vaccinate-remove” (TVR) approach, in which individual badgers are caught, tested and either vaccinated or killed, is being trialled in <a href="https://www.daera-ni.gov.uk/articles/test-and-vaccinate-or-remove-tvr-wildlife-intervention-research">Northern Ireland</a> and <a href="https://gov.wales/docs/drah/publications/180712-delivery-of-badger-trap-and-test-operations-2017-report-en.pdf">Wales</a>. </p>
<p>TVR is as labour-intensive as vaccination but might reduce the numbers of infected as well as susceptible badgers. Unfortunately, the current diagnostic tests for TB in live badgers are not very sensitive, so some infected badgers will be left in the population.</p>
<p>The Godfray Review discusses how combined approaches to controlling TB might have bigger effects than any single approach. Vaccination plus immunocontraception, or short culls plus vaccination, all combined with better biosecurity may be the answer. </p>
<p>But this would require a more joined-up approach than currently exists and an agile policy, responsive to local differences and capable of changing rapidly as new evidence becomes available. And, of course, whatever approach is used to control TB in badgers, reintroduction of infection is possible if the disease is not better controlled in cattle.</p><img src="https://counter.theconversation.com/content/107472/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Malcolm Bennett has received funding from DEFRA and wildlife and farming charities to investigate the role of badgers in the epidemiology of TB on the edge of the cattle epidemic. He also supervises research council-funded PhD students working on various wildlife diseases, including bovine TB.
While not formally affiliated with any relevant organisation, the research involves working closely with stakeholder groups in government, farming, conservation and animal welfare.</span></em></p>The unpopular badger cull has had only ‘modest’ success in reducing bovine TB, according to a recent report. What would an alternative approach that was effective and humane look like?Malcolm Bennett, Professor of Zoonotic and Emerging Disease, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/494752015-10-27T04:14:52Z2015-10-27T04:14:52ZThe threats humans present to wildlife through infectious diseases<figure><img src="https://images.theconversation.com/files/99646/original/image-20151026-18424-89rj7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Frog chytrid may have been spread by humans. It is a fungus that has decimated amphibian species.</span> <span class="attribution"><span class="source">Reuters</span></span></figcaption></figure><p>The threat of diseases moving from animals to people has been the focus of many studies and is well documented in public and scientific communications. 60% of infectious diseases in humans have been estimated to come from <a href="http://www.cdc.gov/onehealth/zoonotic-diseases.html">animals</a>. Nevertheless we need to be concerned about the threat that people present to the health of animals. </p>
<p>According to the Centers for Disease Control and Prevention, the health of humans is connected to the health of animals and the environment. This approach is known as the <a href="http://www.cdc.gov/onehealth/">One Health concept</a>.</p>
<p>A recent <a href="http://planetearth.nerc.ac.uk/news/story.aspx?id=1698">study</a> suggests animals that have been domesticated for longer periods of time are more likely to share their diseases with humans. And we’ve witnessed the devastating <a href="http://onlinelibrary.wiley.com/doi/10.15252/emmm.201404792/pdf">diseases</a> that have emerged from wildlife hosts to affect humans – including the Ebola virus, Hantavirus, SARS, and human immunodeficiency virus (HIV). Yet the impact that the increasing presence of humans and domestic animals in previously pristine habitats has on wildlife is under-reported.</p>
<h2>People spread diseases unintentionally</h2>
<p>Pathogens usually co-evolve with their hosts. This means they reach a balance within a population so that a species will develop defences resulting in co-existence of pathogen and host. But when new interfaces between species occur or there is a disturbance in the ecosystem, this balance may be upset. This results in increased vulnerability to emerging <a href="https://wwww.nwf.org/Wildlife/Threats%20-to=Wildlife/Diseases.aspx">diseases</a>.</p>
<p>An example of this is in chytrid fungus (Bactrachochytrium dendrobatidis) that causes a <a href="http://www.savethefrogs.com/threats/chytrid/">lethal skin disease</a> to amphibian populations <a href="http://www.amphibianark.org/the-crisis/chytrid-fungus/">globally</a>. Some species, like American bullfrogs and African clawed frogs, are resistant to the <a href="http://www.amphibianark.org/the-crisis/chytrid-fungus/">fungus</a>. The accidental or intentional movement of these animals may lead to the introduction of the disease to naïve frog populations. </p>
<p>In the case of some frog species there are a number of human factors which have led to the spread of the disease. These factors have also contributed to the extinctions of some populations. The factors include: global trade in pet and laboratory amphibians, habitat destruction, and the transfer of fungus on equipment and boots of people entering habitats.</p>
<p>People have moved their livestock and pets for centuries. This is not a new phenomenon, as diseases have been introduced to native peoples and wildlife during the European exploration of the New World, the colonisation of Africa, and the establishment of trade routes to the <a href="http://www.jareddiamond.org/Jared_Diamond/Guns,_Germs,_and_Steel.html">Far East</a>.</p>
<h2>The diseases that are spread</h2>
<p>Humans are reservoirs of many diseases. They have an impact on diseases in wildlife through direct interaction as well as indirect activities. </p>
<p>Direct interaction with wild animals include ecotourism, bushmeat hunting, research, and the movement of pets – which carries a risk of disease spread in both directions. </p>
<p>Endangered gorillas live in the mountains of Rwanda, Uganda, and the Democratic Republic of the Congo. They are surrounded by some of the densest human communities in Africa. As a result there has been regular contact between these animals and humans because of: habituation, gorilla movement, human encroachment and beneficial research programs. This has brought these animals into close proximity with people and their pathogens. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/99643/original/image-20151026-18443-rcg2q2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/99643/original/image-20151026-18443-rcg2q2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=365&fit=crop&dpr=1 600w, https://images.theconversation.com/files/99643/original/image-20151026-18443-rcg2q2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=365&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/99643/original/image-20151026-18443-rcg2q2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=365&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/99643/original/image-20151026-18443-rcg2q2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=459&fit=crop&dpr=1 754w, https://images.theconversation.com/files/99643/original/image-20151026-18443-rcg2q2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=459&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/99643/original/image-20151026-18443-rcg2q2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=459&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">From continued interaction with humans mountain gorillas have suffered a decline in numbers because of measles.</span>
<span class="attribution"><span class="source">Thomas Mukoya/Reuters</span></span>
</figcaption>
</figure>
<p>As a result, respiratory infections and parasites have spread. Disease outbreaks and fatalities have been <a href="http://wwwnc.cdc.gov/eid/article/17/4/10-0883">recorded</a> in gorillas due to measles and bacterial pneumonia. We’ve also seen poliomyelitis and measles in wild chimpanzees in <a href="http://www.nytimes.com/2013/08/02/opinion/apes-need-vaccines-too.html?_r=0.ls">Tanzania</a>.</p>
<p>Human tuberculosis (TB), caused by Mycobacteria tuberculosis, is another disease which <a href="http://www.sanparks.co.za/parks/kruger/conservation/scientific/noticeboard/science_network_meeting_2008/Friday/michel.pdf">affects</a> a wide variety of wild animals, including chimpanzees, elephants and rhinoceros. </p>
<p>Although most cases have occurred in captivity, the increased contact between wildlife and humans in these settings presents a risk to animal health. There is also a disease risk in semi-captive situations where animals may also interact with their wild counterparts, especially in countries with a high rate of TB like <a href="http://www.rense.com/general77/eleph.htm">Nepal</a>. </p>
<p>Human TB has been recognised as the cause of deaths in working elephants in Nepal. Awareness has allowed implementation of programs to prevent spread from humans to elephants and minimise the impact of the disease on the <a href="http://www.ntnc.org.np/sites/default/files/publicaations/Nepal%20Elephant%20TB%20Control%20and%20Mgt%20Action%20Plan.pdf">elephants</a>.</p>
<p>Bovine tuberculosis caused by Mycobacterium bovis in cattle was initially recognised in South Africa in 1880, where it is considered an alien disease. By 1928, the first cases were identified in a greater kudu and common duiker. In less than 100 years, this disease has been <a href="http://theconversation.com/why-bovine-tb-is-a-threat-to-more-than-just-cattle-42336xx">found</a> in more than 21 different wildlife species in South Africa.</p>
<p>Bovine tuberculosis has also become established in other populations worldwide. These include badgers and wild boars in Europe, deer in North America, and brush-tailed possums in <a href="http://vet.sagepub.com/content/50/3/488.long">New Zealand</a>.</p>
<p>Indirect activities stem from human development in previously pristine habitats, global travel and climate change. This too has resulted in the increased risk of disease transmission through indirect activities. For example, the human protozoal parasite, Giardia duodenalis, has been <a href="http://www.cfsph.iastate.edu/Factsheets/pdfs/giardiasis.pdf">found</a> in the endangered African wild dogs, mountain gorillas, and beavers. It is believed that people contaminate the environment, resulting in exposure of animals through sewage runoff.</p>
<p>Other less apparent indirect impacts caused by humans include movement or expansion of geographical boundaries for disease vectors such as mosquitoes. The <a href="http://www.cdc.gov/westnile/">West Nile Virus</a> was introduced to the US in 1999, probably as a result of movement of an infected bird or mosquitoes, or possibly travel of an infected <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2094770/">human</a>. </p>
<p>Since that time, massive mortalities have occurred in wild birds, and other native and non-native wildlife in the US. There has also been serious health consequences for horses and humans.</p>
<p>Increased knowledge is needed to understand the role that humans play in diseases of domestic and wild animals. We may contribute to emerging diseases through climate change, habitat use, global and local movements of species, and interactions with animals and their environment. We need to understand better how to mitigate the effects of disease on our <a href="http://www.sun.ac.za/english/faculty/healthsciences/Molecular_Biology_Human_Genetics/animaltb">wildlife</a>.</p><img src="https://counter.theconversation.com/content/49475/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michele Miller receives funding from the South African National Research Foundation. </span></em></p>As much as animals may pass on viruses to humans, humans pass on viruses which are sometimes lethal to the animal world as well.Michele Miller, Research Chair in Animal Tuberculosis, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/423362015-06-01T04:16:32Z2015-06-01T04:16:32ZWhy bovine TB is a threat to more than just cattle<figure><img src="https://images.theconversation.com/files/83456/original/image-20150531-15228-11sbu4b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Buffalo are the main wildlife carriers of Bovine TB, a disease that poses a threat not only to animals but also to humans. </span> <span class="attribution"><span class="source">Thomas Mukoya/REUTERS</span></span></figcaption></figure><p>Bovine tuberculosis is an infectious disease that threatens the welfare of people, livestock and wildlife <a href="http://www.nda.agric.za/docs/Infopaks/Cattle%28bovine%29TB.pdf">across the world.</a> Originally found in cattle, <a href="http://www.cfsph.iastate.edu/FastFacts/pdfs/bovine_tuberculosis_F.pdf">many species</a> of wildlife can also be infected, including buffalo and lion.</p>
<p>The disease is found in many of South Africa’s national parks and may have serious economic, ecological and public health implications. Managing the spread of bovine TB involves restricting the movement of infected animals and in some cases using test-and-cull programmes. This is easier to do with livestock but more difficult among wild animals.</p>
<p>Caused by <a href="http://www.cdc.gov/tb/publications/factsheets/general/mbovis.pdf"><em>Mycobacterium bovis</em></a>, which is closely related to the bacterium that causes human tuberculosis, the bacterium has evolved over time to prefer animal hosts. But it is capable of infecting people and can be difficult to treat with current drug programmes.</p>
<p>The proportion of human TB cases caused by <em>M. bovis</em> varies <a href="http://wwwnc.cdc.gov/eid/article/19/6/12-0543_article">between countries and regions</a>, but is typically around 3% in Africa. These figures most likely under-estimate the true number of cases. Tests to distinguish between the two bacteria are seldom performed.</p>
<h2>Humans are also at risk</h2>
<p>The <a href="http://www.who.int/zoonoses/neglected_zoonotic_diseases/en/">World Health Organisation</a> lists Bovine TB as one of seven neglected zoonotic diseases. This poses a growing public health concern in areas where animals and people live in close proximity such as regions around the <a href="http://www.krugerpark.co.za/">Kruger National Park</a> in South Africa. </p>
<p>In the developed world, cases of people contracting TB from animals are rare. But health officials remain on the alert particularly following the diagnosis of the first cases of <a href="http://www.nhs.uk/news/2014/03March/Pages/First-cat-to-humans-TB-infection-spread-reported.aspx">transmission from domestic cats</a> last year in the United Kingdom.</p>
<p>In developing countries there is a greater chance of the disease being contracted by humans. Interactions between people, livestock and wildlife and the regular consumption of unpasteurised milk and other dairy products puts people at a greater risk of exposure to the disease. Eating game meat from illegally poached wildlife is another potential source of infection, as this meat does not undergo veterinary inspection. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/83370/original/image-20150529-15214-1y7c0c8.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/83370/original/image-20150529-15214-1y7c0c8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/83370/original/image-20150529-15214-1y7c0c8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/83370/original/image-20150529-15214-1y7c0c8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/83370/original/image-20150529-15214-1y7c0c8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/83370/original/image-20150529-15214-1y7c0c8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/83370/original/image-20150529-15214-1y7c0c8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/83370/original/image-20150529-15214-1y7c0c8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bovine TB across the world.</span>
<span class="attribution"><span class="source">World Animal Health Information Database Interface</span></span>
</figcaption>
</figure>
<p>Along the boundaries of many of South Africa’s national parks, local communities and their livestock are in direct contact with wildlife. This increases the possibility of transmission. The disease is most commonly spread by aerosol droplets – coughing, sneezing and spitting - as well as by eating or drinking <a href="http://www.bovinetb.co.uk/article.php?article_id=24">infected animal products</a>.</p>
<h2>The effects of the disease on buffalo</h2>
<p>African buffalo are considered <a href="http://www.sanparks.co.za/docs/conservation/scientific/mission/TPC_BTB.pdf">“maintenance” hosts of bovine TB</a>. They act as reservoirs of the disease and spread it to other species. The infection in buffalo is seldom fatal, though its effects may be more severe in other animals.</p>
<p>Part of the challenge of managing the disease is to limit its spread to rare or endangered species. As a result <a href="http://www.nda.agric.za/vetweb/Disease%20Control/Buffalo/20th%20draft%20protocol%20-%20buffalo%20policy.pdf">restrictions</a> are placed on the movement of infected buffalo.</p>
<p>Buffalo are <a href="http://www.safaribwana.com/ANIMALS/animpages/buffalo.htm">highly valued</a> animals in both the eco-tourism and trophy hunting industries. The establishment of breeding programmes to stock parks and conservancies has created a constant demand for the animals.</p>
<p>The market value of buffalo within South Africa varies according to their disease status. Buffalo that are disease-free fetch approximately 10 times more at auction, with price tags of up to <a href="http://www.bdlive.co.za/business/2013/09/20/buffalo-bull-gets-r40m-as-demand-rockets">$4 million</a>.</p>
<h2><strong>A problem for conservation</strong></h2>
<p>The disease threatens other wildlife species too. Lions, in particular, are vulnerable. They contract the disease by <a href="http://www.felineconservation.org/feline_species/lion.htm">eating infected buffalo</a>. It can also spread to other members of the pride during violent fights, a common feature among adult lions. As they are social animals, an increase in deaths due to the disease may have long term impacts on pride structure and survival. </p>
<p>Little is known about the effects of the infection on a range of other susceptible species such as baboons, kudu, warthogs, leopards making research and surveillance essential.</p>
<h2>A costly business</h2>
<p>The negative economic impact of bovine TB is felt by farmers as well as national parks. Cattle are often brought into game reserves during droughts to access waterholes, and buffalo sometimes break through fences and browse with cattle in surrounding areas. Running continuous cattle and wildlife testing programmes is enormously expensive, and the required slaughter of infected cattle can be devastating to local farmers.</p>
<p>Many game reserves and parks supplement their income with the sale of wildlife locally and abroad. If bovine TB is discovered within their borders, the sale and movement of animals is restricted. This can cause huge revenue losses, and severely limit the funds available to continue conservation efforts.</p>
<p>Bovine TB is particularly concerning in areas where there are communities with high rates of HIV. An immune system weakened by HIV can increase the risk of developing TB infection by <a href="http://www.who.int/hiv/topics/tb/about_tb/en/">up to 31 times</a>. TB infection in people who have contracted the disease from an animal source is increasingly difficult to treat with common drugs.</p>
<p>Bovine TB in South Africa has serious implications for people, wildlife and livestock. There is extensive research focusing on different aspects of the disease, such as immunology and genetics. This work is essential to understanding the disease and managing it effectively.</p><img src="https://counter.theconversation.com/content/42336/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nikki le Roex receives funding from the National Research Foundation (NRF) of South Africa, grant number 88168. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NRF.</span></em></p>People living in close proximity to animals infected with Bovine TB are at a risk of contracting the disease through drinking their milk and eating their meat.Nikki le Roex, Postdoctoral Fellow in Wildlife Genetics, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/286402014-07-02T19:57:31Z2014-07-02T19:57:31ZCattle herd model reveals best ways to halt spread of TB – and a badger cull isn’t one of them<p>Bovine tuberculosis is a major problem in the UK: in 2013 around 8m cattle were tested and <a href="http://www.theguardian.com/environment/2014/mar/12/bovine-tb-cattle-slaughter-numbers-fell-in-2013">32,000 slaughtered</a> at a cost of an estimated £100m, including compensation – a huge economic burden that makes controlling the disease essential.</p>
<p>However, far from controlling bovine TB (bTB), over the past 20 years or so there has been a 10% increase in cases each year. This rise, and the role of TB-infected badgers, is fiercely debated. Badgers were first associated with bTB in the 1970s, but despite the lengthy and expensive <a href="http://www.defra.gov.uk/animal-diseases/a-z/bovine-tb/badgers/culling/">Randomised Badger Culling Trial</a> in the late 1990s there is still limited scientific consensus.</p>
<p>One of the main difficulties in trying to untangle the routes through which bTB is transmitted is the fact that it spreads unseen. In general, infected animals are only identified through a <a href="http://connection.ebscohost.com/c/editorials/34032329/heaf-test-version-cattle-tb-test">skin test</a>, which in itself we estimate to be only 72% sensitive – so 28% of infectious animals are undetected by a single test. With more than a quarter of infected animals going undetected, controlling the disease’s spread is difficult, and identifying how it spreads harder still.</p>
<p>Published in Nature, we have <a href="http://dx.doi.org/10.1038/nature13529">developed a mechanistic model</a> of the spread of bTB within and between around 134,000 cattle farms in Great Britain, between 1996 and 2011. This model accounts for multiple routes of transmission: direct infections between cattle, indirectly through the environment, and through the movement of infected animals between farms. Because the model is mechanistic it allows us to test the effects of different methods of control on how the disease spreads.</p>
<h2>Building a model</h2>
<p>Due to the lack of detailed data, our model does not explicitly include badgers (cattle are ear-tagged, their movements recorded, and are frequently tested for bTB; the same can’t be done for wildlife). Instead we model the combined environmental reservoir of infection – this includes infection from pasture and wildlife species, although it is impossible to separate these two elements. </p>
<p>We don’t feel that this detracts from our findings, as the model is able to accurately capture the trends of infection over time and the geographic spread. We haven’t found any evidence that our model underestimates the rate of infection in regions where badgers are common, which would occur if the model underestimated their importance.</p>
<p>Our modelling approach was able to shed light on the relative strengths of different transmission routes. Unlike the real world where infections can only be seen by testing (and then with limited accuracy) within our simulation model we can track infection perfectly. This allows us to tease apart the causes of infection. </p>
<p>We find that newly infected farms are most frequently due to movement of infected animals, rather than spread through the environmental reservoir, but most importantly the majority of infection originates from the minority of farms. More than 90% of infected farms clear the infection before they cause any secondary cases, while about 2% of farms infect 10 or more other farms. </p>
<p>Our model shows just how complex and multifaceted bTB transmission is, with cattle-to-cattle transmission, failure to detect infectious cases, the movement of infected animals to other farms, and the effects of TB in the environment all playing a role. It is this complexity that continues to deny those seeking to eradicate the disease any easy solutions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/52793/original/dzxdwn52-1404227359.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/52793/original/dzxdwn52-1404227359.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/52793/original/dzxdwn52-1404227359.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=556&fit=crop&dpr=1 600w, https://images.theconversation.com/files/52793/original/dzxdwn52-1404227359.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=556&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/52793/original/dzxdwn52-1404227359.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=556&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/52793/original/dzxdwn52-1404227359.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=699&fit=crop&dpr=1 754w, https://images.theconversation.com/files/52793/original/dzxdwn52-1404227359.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=699&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/52793/original/dzxdwn52-1404227359.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=699&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Model’s prediction vs recorded data of (a) reactor (infected) cattle, shaded region shows 95% credibility from 5,000 simulations, and (b) distribution density of infected cattle.</span>
<span class="attribution"><span class="source">Brooks-Pollock, Roberts, Keeling/Nature</span></span>
</figcaption>
</figure>
<h2>The way forward</h2>
<p>We tested a range of control measures in our model simulation to see what effects they might have. We assumed that these measures began in 2005 and were continued for six years, after which we evaluated their impact. Of ten we simulated, only three measures were found to stop the annual increase in cases.</p>
<p>By far the most dramatic is whole-herd culling of all cattle on infected farms. This would rapidly bring the epidemic under control, as it removes the danger of infected but as yet undetected animals. But it would entail a 20-fold increase of cattle slaughter in the first year, and the political, social, and economic consequences that would bring. However, with the cost of bTB at £100m a year and rising, some form of highly targeting culling could be economically viable.</p>
<p>Vaccinating cattle, which slows the disease’s progression in animals, is also predicted sufficient to prevent the increase in cases, although only just. Such a vaccine would not have the effectiveness we associate with mass vaccination programmes in humans. In any case, the vaccine is <a href="https://theconversation.com/after-the-cull-badger-and-cattle-vaccines-are-still-needed-to-fight-bovine-tb-19746">currently unlicensed</a> and runs into problems with EU legislation.</p>
<p>More widespread and regular testing and slaughter of infected animals in the initial years would identify more cases (we only find bTB when we look for it, after all) and lead to more slaughter, but over time the benefits of a more stringent regime are felt and cases fall in later years. A similar effect can be achieved if we developed a better test for bTB.</p>
<p>What the model also predicted was the relatively limited effect of focusing on environmental factors would be. Even with a 50% fall in the between-farm transmission of infection due to the environment (simulating a substantial badger cull, for example), the rise in cattle infections over six years continues, although at a slower rate.</p>
<p>All three of these measures (culling, increased testing and cattle vaccination) have associated economic costs and benefits, which the government, the livestock industry and the general public must assess to decide the correct course of action. What our simulation provides, based on the latest data, is a way to predict and put numbers to a range of potential policy options. Clearly there is a need to reverse this costly and damaging bTB epidemic, and we hope our findings will help inform decisions in the future.</p><img src="https://counter.theconversation.com/content/28640/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matt Keeling receives funding from Defra, BBSRC, Dept of Health, ESRC and EPSRC</span></em></p>Bovine tuberculosis is a major problem in the UK: in 2013 around 8m cattle were tested and 32,000 slaughtered at a cost of an estimated £100m, including compensation – a huge economic burden that makes…Matt Keeling, Professor, Director of Warwick Infectious Disease Epidemiology Research, University of WarwickLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/235372014-02-21T14:28:56Z2014-02-21T14:28:56ZGene study paves the way to breed more TB-resistant cows<figure><img src="https://images.theconversation.com/files/42193/original/3pj4xcg4-1392983033.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">I for one welcome our new TB-resistant bovine overlords.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-169165043/stock-photo-cows-on-farmland.html">MarclSchauer/Shutterstock</a></span></figcaption></figure><p>Despite scientists’ intensive efforts over many decades, bovine tuberculosis continues to be a problem in many parts of the world, not least in England, where it leads to the slaughter of thousands of cattle every year – <a href="http://www.farminguk.com/news/38-000-cattle-slaughtered-to-combat-TB-in-2012_25163.html">38,000 in 2012</a>. The tiny <em>Mycobacterium bovis</em> bacterium that causes bovine TB has a huge impact on the health of livestock, and farm profitability.</p>
<p>It’s become clear over the past few years that some of the variation in bovine TB is underpinned by the genetic makeup of the cattle. A number of quantitative genetic studies have estimated that the heritability (the proportion of the variation accounted for by genetics) is significant in the major dairy breed, the <a href="http://ukcows.com/holsteinUK/publicweb/Education/HUK_Edu_DairyCows.aspx?cmh=66">Holstein-Friesian</a>. These studies indicate that it would be possible to breed cattle that are naturally more resistant to bovine TB.</p>
<p>Our research paper recently published in <a href="http://www.nature.com/hdy/journal/vaop/ncurrent/full/hdy2013137a.html">Heredity</a> offers new results which indicate that it should be possible to use genetic markers (known as Single Nucleotide Polymorphisms, or <a href="http://ghr.nlm.nih.gov/handbook/genomicresearch/snp">SNPs</a>) to breed cattle that are more TB-resistant. Holstein-Friesian cattle were carefully chosen from herds with high prevalence to ensure that cases and controls were exposed to infection to the same level.</p>
<p>Computerised genetic scanners, known as <a href="http://www.ovita.co.nz/what-we-do/snp-chips-explanation-of-technology">SNP chips</a>, were used to identify differences in the genomes of more than 1,000 cattle that, given equal exposure to infection, had either contracted bovine TB or had not. By identifying more than 600,000 points across the cows’ genomes and combining all the differences detected, it was found around 21% of this breed’s liability to become infected could be accounted for by genetics. This means it’s possible to tentatively identify the elements of the genome associated with TB resistance.</p>
<p>It is important to emphasise that our study compared TB infected cows, as determined by the standard test used by farmers and with laboratory confirmation, with cows that were highly likely to have been exposed to disease, but reacted negatively to repeated skin tests. We carefully chose these animals from herds that had high incidences of bovine TB, and tracked the eventual outcome of the animal to confirm our definitions of them as infected or uninfected were correct.</p>
<p>In other words the genetic trait we investigated relates to TB infection, and not just a differing response to the skin test. We consider that the resistance trait relates to an innate genetic ability to prevent or eliminate infection, not to adaptive immunity.</p>
<h2>TB is a moving target</h2>
<p>At first, TB attacks the white blood cells that help fight infection, and it’s likely that any genetic resistance to TB from the innate immune system, the body’s first line of defence, attacks the pathogen at this stage. This is the most likely explanation for those animals exposed but not infected (controls).</p>
<p>If the animal becomes infected, then the TB-specific <a href="http://missinglink.ucsf.edu/lm/immunology_module/prologue/objectives/obj02.html">adaptive immune response</a> can try to fight the infection, but this is dependent on the innate response happening first. This response takes time to develop, and shows up in the skin test for TB.</p>
<p>But genetic differences are not the only factors – the environment and perhaps even differences between strains of TB also play a role. And while we studied the Holstein-Friesian breed, we don’t know how the genetics of other breeds of cattle, such as those common in beef herds, affect their susceptibility to infection. But there is <a href="http://www.ncbi.nlm.nih.gov/pubmed/22304898">evidence from Ethiopia</a> that zebu cattle that are kept there are more TB-resistant than the Holstein-Friesian breed kept in the UK.</p>
<p>These studies were only possible due to the data on TB infection that is routinely collected in the UK and the Republic of Ireland.</p>
<h2>We can breed better cows</h2>
<p>Future breeding programmes based on an understanding of genetic resistance to TB should be introduced alongside other TB control strategies. A project from dairy farmers’ organisation DairyCo and SAC Commercial Ltd is the first step, and will carry out a <a href="http://www.farminguk.com/News/New-project-will-deliver-bTB-resistant-breeding-for-dairy-cows_26549.html">national genetic evalulation</a> of pedigree data for Holstein-Friesian cattle. </p>
<p>These sorts of genetic evaluations are carried out routinely to select beneficial traits such as high milk yield or long-lived cows. With the costs of bovine TB so high, it makes sense to do the same for TB-resistance.</p>
<p>By starting with the genetic markers our study identified using the SNP chips, this process could be carried out much faster – the SNP data will be more accurate, and the potential improvement in TB-resistance would be seen much more quickly in the next generation of cows.</p><img src="https://counter.theconversation.com/content/23537/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Liz Glass receives funding from BBSRC & EU</span></em></p>Despite scientists’ intensive efforts over many decades, bovine tuberculosis continues to be a problem in many parts of the world, not least in England, where it leads to the slaughter of thousands of…Liz Glass, Professor, Chair of Veterinary Immunogenetics, The University of EdinburghLicensed as Creative Commons – attribution, no derivatives.