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Email received January 7 2010 (Second email received Jan 8 2010 is below and a discussion on vaccination below that)

DEFRA and bovine TB - Dr Paul Gillett, M.B, Ch.B, MRCP, FRCPath

As a hospital medical consultant with 35 years experience specialising in microbial diseases and infection control, I would like to support the remarks made by Dr Ueli Zellweger.

The decline of tuberculosis in humans in this country owes more to improvements in living conditions, better nutrition, less overcrowding and the pasteurisation of milk than it does to the introduction of BCG.

Studies on BCG vaccination in man show an efficacy of between 0% and 70% and appear to depend on country, nutrition and the prevalence of other mycobacterial infections in the population immunised. Thus a policy to control bovine tuberculosis based almost entirely on the use of currently available vaccines is unlikely to be successful even if one could achieve 100% uptake. Trials on new vaccines will take several years to complete given the chronic nature of the disease in both man and animals, and the outcome far from certain. In the short, and probably medium term this means the DEFRA policy is essentially do nothing.

It has to be understood that the current policy of testing and slaughtering infected cattle is aimed at preventing the acquisition of bovine TB by humans not cattle. As Dr Zellweger indicates in his letter, to control bTB in cattle one should be looking to prevent the transmission between and to animals in the herd. This would involve detecting and eliminating sources that pose a threat to cattle and unfortunately the badger is the most important wildlife reservoir that has close contact. I find it inconceivable that two species of animal that are susceptible to the disease and have proven close contact are not transmitting the disease to each other. Introducing proper control measures is therefore to the benefit of cattle, badger, farmer and the exchequer.

Why then are such measures not instituted?

Some would advocate the mass culling of badgers and one must suspect that it is fear of the political implications of public reaction to such a policy which bolsters DEFRA’s inactivity.

There is an intermediate and more appropriate strategy. I am reliably informed by countrymen that it is possible to detect diseased badger sets by inspection of the runs and other signs. Thus it is possible to avoid mass culling - which may actually be counter-productive - in favour of selective elimination of diseased animals. A measure which is to the benefit of the badger population as a whole and the cattle. A group of concerned West Country farmers and vets have recently produced a DVD* outlining the present problems and the potential for training others in the recognition of diseased sets. It is to be hoped that a coherent policy may be formulated about such an approach.

Should an effective vaccine and delivery system become available in due course, then it would be (as in humans) an adjunct to rather than a replacement for effective infection control measures.

* - Bovine TB – A Way Forward, a film by Chris Chapman, will be released at the end of January. For details go to the homepage and click on FILM

Email received January 8th 2010 from Dr Paul Gillett, M.B, Ch.B, MRCP, FRCPath in response to comments by Dr Colin Fink