Professor Malcolm Bennett, School of Veterinary Science
“You can hardly have watched or listened to a news programme recently without encountering a bad tempered ‘debate’ about bovine tuberculosis, and the role culling badgers plays in its control.
“If you already had a view, or even if you didn’t, none of this will have changed your mind, not least because the issue is often presented as a simple punch up between Brian May and the National Farmers’ Union. Neither gets to, nor often seems to want to, discuss the limitations of the (usually selective) evidence or to introduce much nuance into the arguments. And the politicians have managed to turn the whole issue into a party-political one, both sides claiming to have science on their side (at least when people claim to have God on their side, you know what to expect).
“Meanwhile, chugging along behind this screen of noise and smoke is a policy heritage in Defra/MAFF that has evolved over decades and spent large sums of money in the process: a policy which, unlike the modern milk tanker, is very difficult to turn around. Abandon hope of reason all ye who enter this debate, you might be forgiven for thinking.
“And yet, and yet… if you screw up your eyes and wish very hard some hints of colour can, perhaps, be glimpsed in this otherwise very black and white landscape. The first is a European Commission report on the control of TB in the UK. The sentence that caught my attention reads: “UK politicians must accept their responsibility to their own farmers and taxpayers as well as to the rest of the EU and commit to a long-term strategy that is not dependent on elections”.
“Hurrah, I thought, not so much a wake-up as a grow-up call. However, I have to confess the comment is more a criticism of Welsh policy daring to deviate from Defra’s than a real call for political maturity. And while it’s easy to agree with much of the report, it still takes a rather simplistic view of the badger issue.
“More colour can be found in the consultation document; Bovine TB: A call for your views on strengthening our eradication programme and new ways of working, just launched by the Animal Health and Welfare Board for England, a Defra advisory group. This consultation is aimed mainly at farmers and vets. As well as asking their views on various control measures in cattle, including stronger control measures in cattle and regional variation in approaches to control, it starts a welcome discussion about the fundamental issue of ownership of the problem.
Time for real political debate
“Don’t get me wrong, I not only appreciate but fully agree that science can only inform policy, and it is the politicians not the scientists who should be making that policy. But it is deeply frustrating to see so much political energy put into hurling around ill-understood (and sometimes deliberately misunderstood) scientific evidence, and almost none into the big political questions that science cannot answer.
“Who ‘owns’ this disease? Is it the government or the industry, the Minister or the farmer? Is it important? If so, to whom? The control of bovine TB certainly costs a lot, but using that argument merely suggests that spending more money on control would make the disease more important. So how much effort are we willing to put into its control? And, crucially, who is willing to pay? Here, at last, are some big political questions for our politicians to debate.”
The following extract from the above article,
“The control of bovine TB certainly costs a lot, but using that argument merely suggests that spending more money on control would make the disease more important. So how much effort are we willing to put into its control?”
tempts the thought of whether we should be spending so much effort on bovine TB control.
In the extreme, if there was no control of the animal health disease then bovine TB would increase dramatically and then it would be a huge occupational health risk. Also any failure of systems could then have potential for public health risks.
Thanks for this exchange. Currently I am helping a student prepare a journal submission focussing on the Welsh policy (this is public policy piece not a clinical article). Two questions: 1 if a vaccine is licensed and sanctioned for badgers why is it ’10 years off’ for cattle? 2 Is there any evidence post-pasteurisation that the infection ever gets through to humans (even if the milk is infected)? Thanks (Dave Pilgrim Professor of Health and Social Policy, Department of Sociology)
Interesting comments about an issue that impinges on animal welfare,politics,economics and sentiment,An aspect that gets little attention is the effect of TB on badgers- a debilitating(and ? painful) infection, in contrast to this infection in cattle that is now uncommonly clinical.Is there a case for badger culling in the interests of reducing this suffering in this wild animal species?.Or should there be private or public funding of the cost of long term antibiotic treatment of trapped and tuberculous badgers.At present there is no evidence that BCG vaccine is effective in preventing TB in badgers or cattle.As far as I am aware properly conducted pasteurisation is effective in making TB infected milk safe for people,hence the public health argument about bovine TB has not been very strong.
I’m not sure that I agree about no evidence for the efficacy of vaccination in badgers – and I suspect that if badgers were humans, then with the evidence we have there would be a lot more vaccination going on. But time will tell.
The argument for culling badgers as a welfare measure is an interesting one. I could kind of buy this idea if we were going to catch badgers, give them a health check (remembering that we don’t have any good bed-side tests for TB in live badgers) and then, based on that, decide euthenasia was the best option. But I’m not sure about the ethics of culling at a population level for the benefit of an unidentified number of individuals.
Disease and welfare in wildlife is always a mine field even if you throw in the argument that the badgers probably got TB from cattle in the first place so all we’re doing is fixing a problem of our own making. Certainly there is increasing evidence that TB, even when badgers have extensive lesions that would be associated with severe disease in humans, has little effect on survival or reproductive success in badgers. I don’t know how you convert that into welfare, however.
I’m off to a joint medical-veterinary conference on the problems of antimicrobial resistance tomorrow: I doubt anyone there would like the idea of giving wild badgers long-term antibiotic treatment!
David asks about vaccination and the effectiveness of pasteurisation. There is a recently licensed injectable vaccine for use in badgers: it’s too early to say for sure how effective it is but the published (and some unpublished evidence Iâ€™ve seen) so far suggests it should be useful. Of course there are different measures of effectiveness, and my view is that the only one that really matters (not withstanding Don’s question about badger welfare) is whether or not its use prevents transmission to cattle. It is also expensive, not least because it is injectable. An oral vaccine would obviously be more easily distributed to badgers, and such vaccines are in development. The very early evidence on oral vaccines suggests they also might also be effective at reducing infection in badgers. Vaccination in cattle has been trialled in the past and is being worked on currently. The immediate problem (and why there has been relatively little research on vaccines for use in cattle) is that we can’t tell vaccinated from infected cattle as the best diagnostic tests for infection are tests for the cow’s immune response to TB rather than directly for infection – so you would have difficulty combining vaccination with a test and cull approach. Hence there are EU and international trade regulations that prevent us from vaccinating cattle and, until recently, little political will for challenging these international regulations. I haven’t looked back in the literature to check this, but I have been told that back in the early days of bovine TB control in the UK, when badgers did not appear to be part of the epidemiological picture so life was easier, some trials were done comparing control by test and cull with vaccination. Both, apparently, worked but test and cull eradicated infection from a herd much more quickly than vaccination. As is true of most vaccines, while vaccination can protect against infection (though at nothing like 100%) it has little or no effect on already infected animals.
Pasteurisation prevents transmission to humans via cowsâ€™ milk and is arguably the main reason why human infection with bovine TB is now rare in the UK. You can, of course, still buy un-pasteurised milk and milk products (though not in Scotland), but only when clearly labelled and from herds regularly tested negative for TB and usually in areas where we donâ€™t (yet) find bovine TB. Thereâ€™s a whole other debate about whether or not the sale of unpasteurised milk and milk products should be banned. Personally I buy such cheese from several local cheese-makers and object to people wanting to take that choice away from me (see the Food Standards Agencyâ€™s web site for the alternative view!) Most human cases of bovine TB infection occurring in the UK nowadays (and there are less than a handful each year) are either imported cases or reactivations of infections from years ago â€“ and sometimes both. A very small number are in farmers who drink their own milk before it is pasteurised. So itâ€™s not currently a real public health issue. However, pasteurisation does sometimes break down â€“ ie people make mistakes – especially in small, on-farm dairies, and we have seen outbreaks of E. coli O157 associated with this. So I guess it could be argued that the more bovine TB there is, and the more widespread it is, the greater the risk of a human infection due to human or mechanical error during pasteurisation. Iâ€™ve not seen this modelled though â€“ has anyone else?
I think, Richard, that you voice a common frustration. And that’s why I see a glimmer of hope in this new consultation – I hope you respond to it. I’ve seen signs, and particularly in the last few weeks and in personal conversations, that both Defra and the NFU are much more open to debate on how bovine TB should be controlled. Farmers, particularly locally, are pretty reasoned about it, too, with a range of views on the what should be done. So I hope they, too, respond to the consultation.
As farmers in England are handed badger-culling responsibility, it is indeed high time to take a little distance of perceived solutions to the BTB problem and re-consider. The ever-increasing English and Welsh efforts aiming to control BTB have become a classic case of â€˜the emperorâ€™s new clothesâ€™. Hundreds of millions of pounds spent, research commissioned and long years of hard work up and down the country, the control efforts themselves, have become more important motives than the disease. At this stage, it may have become too embarrassing to question our actions, let alone the problem itself. I would like to take this opportunity to point out that, to me, the emperor seems pretty naked.
We have to start at the beginning again, and clearly define why BTB eradication is actually so important to us. DEFRA policy on the BTB problem is mainly driven by the â€˜protection of public healthâ€™ but does not appear to be based on risk analysis. In reality, since the pasteurisation of milk was introduced in the 1950s, BTB eradication neither significantly improves public health nor provides value for money (Torgerson and Torgerson, 2010). What exactly is the BTB-associated risk to public health in the 21st century and are there perhaps more cost-effective ways to lower it?
A second driver behind our efforts is the protection of animal health and welfare; or at least we like to think so. But why would we prioritise TB in this respect? Do we have any biomarkers to show that a cow wasting away while fighting BTB is suffering more than a cow in negative energy balance related to a genetic drive to produce milk (which is artificially increased by us)? Currently, clinical BTB in cattle is virtually non-existent! Were the welfare of cows our main concern, BTB testing at time intervals preventing cows to become clinically ill would suffice. But, letâ€™s be honest, it is hard to claim we are truly driven by the protection of animal health and welfare when vets up and down the country seem to embrace a random shoot-out of badgers by their clients.
Like it or loathe it, in the end there is only one debate to be had: what is the most cost-effective way of dealing with this disease? More intensive testing is not an option; over the years, we have proven that this will just detect ever more (immune responses to) BTB; we cannot control let alone eradicate it this way. A cost-benefit analysis of a badger cull has been carried out; it was found not to be economically feasible (Wilkinson et al, 2009). In the longer term, the only â€˜cheapâ€™ way to deal with this disease is the vaccination of cattle. However, a licensed vaccine is perhaps 10 years away.
In the meantime, the solution to our BTB problem may lie in re-defining the problem itself. â€œBecause we always did itâ€ cannot be the foundation of BTB policy. It has been pointed out that UK de-regulation of BTB would block all cattle exports to Europe. Again, a cost-benefit analysis would provide a straightforward answer here. Meanwhile, instead of debating badger culls, efforts could be directed towards seeking derogations from EC legislation or, better, re-defining the BTB problem at EU level.
Torgerson, P.R. and Torgerson, D.J. (2010) Public health and bovine TB: whatâ€™s all the fuss about? Trends in Microbiology 18, 67-72.
Wilkinson, D. et al (2009) Cost-benefit analysis model of badger (Meles meles) culling to reduce cattle herd tuberculosis breakdowns in Britain, with particular reference to badger perturbation. Journal of Wildlife Diseases 45, 162-188.
I have worked in the cattle livestock industry for over 40 years and I have no evidence that anybody, either in Defra or academia, listens to those people who do not shout from the rooftops or from exalted positions of influence regarding controlling this disease. The British Cattle Veterinary Association have influenced the British Veterinary Association to side with farmers in support of a badger cull without considering all the scientific evidence related to controlling a disease where there may be a reservoir of infection within the wild animal population of a country. The political, ethical and economic aspects for animal disease control at a national level in the UK have been ignored, and ordinary lower mortals, like me, have never been invited to contribute an opinion based on experience covering nearly half a decade. History involves reflection on the past: it is a shame the lessons of the past have not been better considered by the strident voices of today.
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