Bovine TB Part II: rotten data, dodgy science, bad politics.

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Relying on badger culling to eradicate bovine TB is just plain stupid, writes Tom Langton
Ecologist Tom Langton continues to make the case that the only way to eradicate bovine TB is through proper testing and not through badger culling which simply doesn't work
How is it possible that such senior figures can be so misinformed?

My first article published on this site under this same heading attracted comment from a wide spectrum. Perhaps surprisingly - and helpfully - both ends of that spectrum seem to agree now that the notion of the Random Badger Culling Trial (RBCT) perturbation effect increasing badger transmission of bTB has been shown to be an unsafe concept. However, many of the commentators appear to have missed the relevance of the bTB spike in two of the ten central England control areas.

It is the unexpected - roughly 10% - contribution from each of these that make up around 20% of the difference between the control and the proactive cull areas; in other words most of the supposed 25% proactive cull benefit. 

Why did breakdowns spike in two of the control areas? Perhaps it was because they had the two highest ‘starting’ levels of bTB herd infection (37% & 28% respectively) in the years immediately before the trials.

To spell out the significance of this, the supposed benefit from the proactive cull appears not to be real and not real by a very big margin. The claimed bTB reduction seems instead to be a function of other factors occurring in the field that have not been adequately controlled.

In fact the data from the ISG final report in 2007, Tables 5.1 and 5.7, indicate that the paired comparisons (proactive cull to control) of new herd breakdowns in four of the ten trial areas, (Cornwall/Devon, Devon, Devon/Somerset and Gloucestershire), were lower in the control area than in its respective cull area. There was no benefit trend in the proactive cull areas. This does not seem to have been widely appreciated yet it is an obvious cause for alarm bells. 

On 5 May, DEFRA Minister George Eustice was asked in Parliament by Neil Parish, chair of EFRA scrutiny sub-committee the following question: "When will the Minister be able to give the scientific figures for the badger cull areas to show the reduction in the amount of disease in cattle?" However, DEFRA announced around the end of last year that any bTB reduction from culling would not be measurable. Eustice answered “The reality is that the programme is a long-term commitment and it will be several years before we can see the impact of the culls.”

Again, not true, in his own department’s view. 

http://www.theyworkforyou.com/debates/?id=2016-05-05a.290.5&s=OLIVER+COLVILE

Eustice continued on timing; “As my Hon. Friend knows, the randomised badger culling trials a decade or more ago found that the benefits of the culling of badgers were only seen some four years after the conclusion of the culls”. But the fact that any supposed benefit cannot be measured makes any implications sterile.

How is it possible that such senior figures are so misinformed?

Much was asked of the RBCT, but like the many field experiments before it, it has proved a near-impossible task to control for the huge number of variables in field conditions. This has been compounded by inadequate scientific disease investigations relating to wildlife.

How is it possible that such senior figures can be so misinformed?

In cattle, bovine TB needs detecting with the IFN gamma interferon test (for early stage bTB), in tandem with the SICCT skin test. Further tests, either a fast blood antibody or PCR test complete the minimum three-stage checking needed in order to include the later stage ‘sleepers’ and complete an comprehensive approach to detection. Whole-herd depopulation may be minimised with this approach in some areas too.

A few weeks ago George Eustice released figures following a Parliamentary Question by Kerry McCarthy MP revealing that gamma interferon testing is all but abandoned in the High Risk Areas. 

http://www.parliament.uk/business/publications/written-questions-answers-statements/written-question/Commons/2016-04-13/33912/

This is further evidence that the UK strategy has been only to try to lightly slow-up bTB’s proliferation, rather than to tackle bTB head-on, in all areas, as it must do to attempt eradication. Public funds are being poured into bTB slaughter compensation in a method that can only perpetuate the spread of bTB and result in higher levels of crisis and cost. 

The point is that any available money now needs to be placed urgently but expertly into effective testing, in order to help beef and dairy farmers properly tackle the disease. Otherwise the other spending is wasted.

The cost is perhaps up to £100 per animal and our veterinarians should surely be pressing to get the job done? Why would the public continue to pour compensation payments into a system that fails to adequately address the problem? Good money frittered on the now exposed dodgy badger killing policy is a scandalous waste –the money better spent on testing. The even bigger scandal is how long avoidance of any real solution to the wider problem has been allowed to persist.

Tom Langton has been a consulting ecologist to government, business and industry and a voluntary sector volunteer, more recently working on assisting small pressure groups in their legal opposition to destruction of species and habitats in Europe.

 

 

 

 

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