Is the existing bovine TB eradication policy really working?

One of my favourite sources of information about bovine tuberculosis (bTB, caused by Mycobacterium bovis) is bovinetb.co.uk. Its unnamed author is ‘looking for the reform of a costly and misguided system.’

When I talk to farmers, I often hear support for anything that might be supposed to help control bTB. That view is based on knowledge of how terrible is the existing policy of slaughtering cattle (Bos primigenius) which react to the ‘skin test’ (the single intradermal comparative cervical tuberculin (SICCT) test). Indeed it’s terrible for farmers. But is it the only way? Not everybody thinks so.

Here’s what bovinetb.co.uk says to the question, ‘Is the existing bovine TB eradication policy really working?’

‘Is the existing costly and disruptive programme that aims to eradicate bTB in the UK good value for money and is it really working? NO. Is the existing policy now having more of an adverse impact on human and cattle welfare than the risks from the disease it is aiming to control/eradicate? YES. Over the last few years there have been at least two human deaths – not from bovine TB but as a result of the skin test. In April 2010 an Irish farmer died and in January 2013 a Carmarthenshire [South Wales] farmer died. Many farmers and vets are injured during the testing process. Cattle too are frequently injured or killed. Would it be more sensible instead to have a control policy, rather than one that aims for the impossible – eradication? YES

‘Since the 1950’s, when the testing of cattle for [bTB] in the UK became compulsory following its initial introduction on a voluntary basis in the 1930’s, many millions of pounds have been spent on trying to eradicate the disease using an imperfect skin test. However, despite some 60 years of testing and all this expenditure, and many thousands of slaughtered cattle, little progress has been made, and the financial costs continue to escalate year on year. Perhaps more importantly, the government has done little to determine the true costs of the existing testing policy; the consequences of the enormous pressures on cattle and alpaca [(Vicugna pacos)] owners; business failures as a result of herd breakdowns, health and safety risks from cattle handling and the actual consequences of culling indigenous wildlife species … the existing policy is a bureaucratic nightmare. It is starting too to involve an even greater number of people and animals as legislation is being brought in to test/cull wildlife and other domestic animals.

‘What is clear is that after 60 years of using the same old test (which is not reliable enough to be anything other than a herd test), culling thousands of cattle, and millions of pounds of public expenditure spent on compensation payments, research etc, the existing eradication (elimination!) policy is impossible to achieve and sustain whilst the bacteria that causes bovine TB [in fact a single bacterium, M. bovis] is so endemic around the world and globalisation continues to increase. As this website clearly reveals, the current insistence on striving for eradication is undoubtedly causing more suffering to farmers and their animals than the risks of the actual disease itself. The Government persistently fails to adequately justify the need for such an expensive and draconian policy, either on the grounds of human or animal health or even on economic grounds. As the skin test is not used as a herd test in the UK it will be impossible to eradicate the disease and we should be learning, instead, to live with it. Countries that have used the skin test as a herd test, destroy the whole herd if any animals fail. This has enabled countries to maintain the coveted bTB free status. However, most people would probably agree that this is not an appropriate option for the UK. Instead we should be vaccinating cattle.

‘Are too many people now being adversely affected by the current policy? With the recent decision by WAG [Welsh Assembly Government] to bring in compulsory testing for other domestic animals, an even greater number of people will be affected. It would seem that the main reason for trying to eradicate bTB is so the UK can maintain its ‘TB free status’, thereby protecting the agricultural industry’s dwindling cattle exports. Is it now time for a radical re-think? Bovine TB appears to be yet another area that has become ‘big business’. Is it now being driven by vested interests?

‘The current pre-occupation with bTB may sound particularly surprising when you consider that the risk to humans these days from bovine TB is negligible – pasteurisation and cooking destroys any TB bacteria in milk and meat. In fact the risk to humans is so minimal that even the unaffected parts of carcasses of cattle slaughtered as TB reactors and found to have TB lesions are sold back into the food chain for human consumption.

‘Those countries which claim to have eradicated bovine TB using the skin test have achieved this by using very stringent measures, such as complete depopulation of herds, delays on re-stocking and even the removal and sterilization of soil! It is interesting to note that no country with so called wildlife reservoirs, has been able to achieve this coveted status to date.

‘Despite the massive costs over the last few decades, the exact details of the transmission and epidemiology of bovine TB are still not known with complete certainty and there are a number of important, unanswered questions which are fundamental in justifying the existing test and cull policy. Have we got to the stage when the huge costs and negative effects on cattle owners as a result of the existing policy outweigh any perceived benefits of the existing policy and should there be a radical re-think on the whole issue? Perhaps lessons can be learned from countries such as Ethiopia, where they just cannot afford to persistently test and kill cattle needlessly. Neither can they afford to spend millions of pounds on investigating so-called wildlife reservoirs. Instead, they are opting for control and are trialling vaccination of cattle. The results are encouraging, as have been previous cattle vaccination trials in other areas.’

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About argylesock

I wrote a PhD about veterinary parasitology so that's the starting point for this blog. But I'm now branching out into other areas of biology and into popular science writing. I'll write here about science that happens in landscapes, particularly farmland, and about science involving interspecific interactions. Datasets and statistics get my attention. Exactly where this blog will lead? That's a journey that I'm on and I hope you'll come with me.
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17 Responses to Is the existing bovine TB eradication policy really working?

  1. Littlesundog says:

    Interesting post! This is another overwhelming (to me) issue regarding “big business”. Thank you for sharing this information.

  2. ssimples says:

    Bovine TB is one of those problems where there is no easy solution.

    However I shall first of all take issue with you regarding the impact of whole-herd slaughter on the TB situation in countries outside the UK and Ireland. Consider for example what has happened in Cumbria in the UK.

    Cumbria is a large county which has a dense population of cattle. In fact cattle density is much greater than in Gloucestershire. In 2012, cattle per sq km in Gloucestershire was 38 and in Cumbria it was 67. About half of Cumbria’s cattle were destroyed in 2001 as a result of Foot and Mouth. Cattle from all over the country, many of which were overdue for TB testing due to suspension caused by F & M, were then brought into the county to fill the void. As expected, strains of TB specific to Devon were seen in parts of Cumbria for the first time after this restocking process. In most of Cumbria tests were performed only once every 4 years. In 2004 TB peaked in Cumbria. However after a further 3 years of localized increased herd testing, TB fell back to original levels. Today Cumbria is regarded as a low risk county and herds in most of the county are still only tested once every 4 years. This illustrates how effective the skin test is as a herd test for reducing TB and why other countries who use the test and aggressively control disease in wildlife like France and Germany have a TB problem which is tiny compared to that in the UK and Ireland.

    In view of this, I suspect that the reason why these countries have maintained TB free status is not because of any whole-herd slaughter policy but because of the way in which they control disease in their wildlife. In a 55 sq km area of Gloucestershire where badgers were vaccinated in a trial between 2006 and 2009, out of 300 badgers tested for TB each year about 50% of badgers (after accounting for sensitivity of the combined test methods) were found to be infected! This is likely to result in an enormous disease burden in Gloucestershire when cattle are turned out to pasture each Spring. In terms of the proportion of restricted cattle herds, Gloucestershire is the worst county in Great Britain and has clearly been so for the last decade.

    Regarding relaxing the current testing regime and hence control of TB in cattle, this would bring the prevalence of disease in cattle closer to that currently in badgers. Doing this is likely to considerably increase the burden of infection in the environment due to increased cross-species transmission. If this is done, confidence is needed in systems being able to cope when disease prevalence builds up in both species. Regarding the importance of cross species transmission and the role it is likely to be playing, consider the situation in South West England when TB was very low in the 70’s and early 80’s. During these years TB was only persistent in isolated pockets of the country. The discovery of infected badgers in these pockets was a good indication that cross-species transmission was occurring in these small areas. Although the relative strength and dynamics of transmission from cattle to badgers, from badgers to cattle and between the same species, is currently not well understood, in November 2012 direct genetic evidence of TB persistence reported on farms suffering multiple outbreaks was found to be closely correlated with a continued, ongoing interaction with infected local badgers.

    When infection is high in badgers and increased in cattle, do we really know what will happen, and on reaching any situation where problems start to occur, how easy will it be to then minimize the impact of this elevated chronic disease? Christl Donnelly who was partly responsible for designing the RBCT badger culling trial between 1998 and 2005 said on BBC’s Farming Live program on 28th July 2011 the following.

    [START OF QUOTE]
    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.
    [END OF QUOTE]

    Reducing cattle controls will move towards this situation and to my way of thinking would significantly increase risk. Perhaps I have misunderstood your article, in which case I apologise, but I would not regard any policy which increases disease levels in the environment due to relaxed cattle controls as sensible.

    Regarding vaccination, vaccination of badgers in clean areas may bring some benefit but in highly infected areas in the absence of culling infection levels may still be high even after 25 years.

    In cattle the BCG vaccine is extremely expensive when the cost of the DIVA test is considered and may not be worth the limited reduction in the number of herd breakdowns which it is likely to save in view of the vaccine’s limited effectiveness.

    If the disease front reaches and starts to absorb Cumbria, England’s cattle industry will most likely be in real trouble. At this point a lot more of the farm produce which we eat will probably be coming in from Ireland and France.

    • argylesock says:

      In fact this article isn’t really mine: it’s a long quotation from bovinetb.uk. As I learn more I continue to update here.

      Do you advocate relaxing the current system of cattle testing and slaughtering? I don’t. But I think it’s an example of, ‘If you do the thing you’ve done before, you’ll get what you’ve got before.’ I agree with Owen Paterson and David Heath in a general sense – a broader ‘raft’ of measures against bTB is appropriate – but I don’t always agree with their specific choices.

      One thing they get right, in my opinion, is their concern about cattle being moved around too much. The story in Cumbria is informative, as you point out. A knock-on effect of the Foot and Mouth crisis. The response to FM (all those slaughtered herds, never catching up with the disease’s spread) was a terrible mess. That’s another story but it does seem to have affected bTB when people restocked their farms.

      What do you think of the changes which came into force nearly a year ago? https://www.gov.uk/government/news/cattle-movement-controls-and-surveillance-strengthened-to-tackle-bovine-tb

      You mention Gloucestershire. Do you know why that county, and other parts of the West Country, are bTB hot-spots? Everybody agrees that they are so but I’ve seen no discussion of how that situation came to be.

      It sounds as though you agree with Christl Donnelly. I’m inclined to trust her as a scientist who contributed to the RBCT badger culling trial. However, I doubt her when she says that an increase in bTB could ‘have potential for public health risks.’ That sounds like a prediction that human cases of bTB would rise, which doesn’t seem likely in my opinion.

  3. Pingback: What the British government is doing about bovine tuberculosis | Science on the Land

  4. Pingback: Getting rid of bovine tuberculosis? | Science on the Land

  5. ssimples says:

    In reply to…

    [START OF EXTRACT]
    You mention Gloucestershire. Do you know why that county, and other parts of the West Country, are bTB hot-spots? Everybody agrees that they are so but I’ve seen no discussion of how that situation came to be.
    [END OF EXTRACT]

    Problem is most likely to be TB in badgers.

    In Gloucestershire half were found to be infected with TB when 300 badgers were tested each year from 2006 and 2009. Cumbria is more cattle-dense than Gloucestershire but has tiny TB compared to Gloucestershire.

    In the 1970’s pockets of persistent TB in cattle were discovered in the South West. Ministry vets attributed this persistence to infected badgers found in these areas. These persistent “pockets” have steadily grown in size so that today these pockets cover wide areas.

    This is unlikely to be due to cattle movement and farming practices. If it were, the large cattle movements in Cumbria is not consistent with the county having one of the lowest levels of TB in England.

    • argylesock says:

      You may be right. Did anybody do proper epidemiology? I mean identifying strains of M. bovis in badgers and in cattle sampled from the same area at the same time. Hm, I feel another blog post coming on! You might know that strain-typing is one of the things I did during my PhD, but for a different pathogen (Toxoplasma gondii) and I personally haven’t used any strain-typing technique on M. bovis. But iirc such a technique exists.

      Meanwhile as you know, the ‘pilot cull’ in Gloucestershire was called off due to a smaller badger kill than expected. Not jumping to any conclusion about that.

      • MARYORIORDAN says:

        I CAUGHT MY SO CALLED VET MAKING REACTORS OUT OF MY PERFECTLY CATTLE IN 1977 ,,IGOT THEM RETESTED BEFORE SLAUGHTER ,, THAT WAS THE LAST OF MY CUNT OF A VET AND HADNT A RECTOR SINCE

  6. ssimples says:

    In reply to…

    [START OF EXTRACT]
    Did anybody do proper epidemiology? I mean identifying strains of M. bovis in badgers and in cattle sampled from the same area at the same time.
    [END OF EXTRACT]

    the following paper may be of interest

    Whole Genome Sequencing Reveals Local Transmission Patterns of Mycobacterium bovis in Sympatric Cattle and Badger Populations. Roman Biek et al. PLOS Pathogens | http://www.plospathogens.org. Published November 29, 2012.

    This paper and others are referenced and the topic of transmission between badgers and cattle are discussed at

    http://www.bovinetb.info/transmission.php

    The direction of transmission from one species to the other was not identified in the above paper but with more extensive sampling and analysis, there appears to be prospects for doing so.

  7. mary oriordan says:

    cattle t b i s a mystry to billions of people,,,,, but not to the people that are making their living from this scandal for the past 60 years,,TB IS ABOUT THREE THINGS ,, MONEY ;; POLITICS .. AND TRADE,,, THERE IS ONLY WAY OF SCAPPING THIS CARRY ON AND THAT ISTO GET A PERSON ELECTED INTO THE NEXT GOVERMENT ,,,, GOVERMENT BODIES AT PRESENT KNOW NOTHING ABOUT THIS SCANDAL,, SO A PERSON HAS TO BE PREPAIRED AND CODITIONED

  8. mary oriordan says:

    why have my herd been tb free for over 30 years,, because i caught my so called vet making so called reactors out of my pefectly healthy cattle,,i could not get scandal exposed because im only a thing;;farmers please wake to these cunts of vets;;; because the scheme is compusory these bastards have power over you ;;but is u have the power over them to give them akick up in arse and put them out side your home and farm yard ..u hit their pocket ,,,give them the sack .. if i hadent copped onto this blaguarding ..i be going around like ajack ass asking questions about badgers;; rats etc ;;;;; britian and ireland havent a single animal having t b,, only the best cattle in the whole world…the so called reactors ,,are put into the food chain unknown to people and shops and supermarkets;;i cannot get a news paper or journalis;; radio or t v to broad cast this injustice

  9. mary oriordan says:

    the t b scheme is defnetly working for all the people that are earning billions from the scandal for the past 60 years

  10. MARYORIORDAN says:

    cattle t b is big buisness if aFARMER HAD ONE REACTOR IN HIS HERD ,,BY THE TIME THAT H ERD WOULD RESTORED TO GOOD HEALTH IT IS COSTING THE COUNTRY 35,000 EUROS ANDFOUR AND AHALF THOUSAND TO CATCH A BADGER

    • MARYORIORDAN says:

      IS IT POSSIBLE TO HAVE THIS T B SCANDAL SCRAPPED ;; HOW IS IT THAT THE MINISTER OR WHO EVER IS IN CHARGE OF THIS BOLLIXING ISNT ARRESTED AND JAILED FOR ALLOWING 30,000 TB CATTLE INTO THE FOOD

  11. marytoriordan100@hotmail.com says:

    with 2016 upon us and the new 60/000 healthy beautiful cattle that will defnetly be slaughtered over the next 365 days; in in g b and southern ireland ; will not surprise the innocent farmers that are going to become victims,, keep on sleeping and talking , about ,badgers, deers ; cats dogs,, slurry.. water troughs . cattle movements, foot dipping , policing, shooting ;trapping caging innocilating; valuing ;; hardship fund , retesting ,disenfecting.. depopulating ; compensating ;restocking; haulage to the most exereme part of the country;; five thousand victims locked up anually,, and no hope of locking the cunts that that are carrying on this blaguarding; the british agr minister is implimiting another new scheme that will go as far as 2041,, here , hear

  12. marytoriordan100@hotmail.com says:

    with 99.98 percent of our cattle t b free all our lives,,,,, the .02 percent are incurable and costing billions annually,,,, so the .02 percent t b reactors make their way to the supermarkets as prime beef,, all the various comments by innocent people are very sad,alittle knowledge is adangerous thing ,, example;;;vaccination according eu standards ; so vaccination must be forgotton if u dont want prosecuting …how can this scandal be ended

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