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A brief history of TB in Great Britain

01 June 2017, at 12:00am

We spoke to John Blackwell, a veterinarian who has long been involved in the fight against bovine tuberculosis, about the evolving role of the OV with the rise in cases across Great Britain over the past 30 years.

John Blackwell is Clinical Director of Independent Veterinary Care in Shropshire, where he has worked since 1988. He is a long-standing member of the British Cattle Veterinary Association and was president of the British Veterinary Association in 2014 and 2015. John has worked in mixed practice for almost 30 years, but the vast majority of his workload has centred around farm production.

Changing practice

Beginning his veterinary career in the late ’80s, John has seen the rise in bTB cases first-hand. He recalls how the training has changed: “I had my Local Veterinary Inspector training soon after qualifying – I probably had one day’s training with the local vets at Barton Hall in Preston; they came out and saw me do a TB test and that was pretty much it!”

The methods used when John qualified were a far cry from the current practices of evaluation, accreditation and revalidation. John praises the new requirements. “Going through the modules, even for people who have been doing it for a very long time, helps us to re-focus on why we’re doing it,” he says. He notes that the current bTB test is effective and has been used to clear TB from other countries, but that “it needs to be performed to a high level and to be made as standardised as possible”.

Bovine TB was being controlled at a low level in the 1970s. “If we had an inconclusive reactor back in the day,” John recalls, “my then boss and myself would turn the office upside down looking for the necessary forms to put the farm under restriction. Now of course, we carry them in the car.”

Why the increase?

Precisely why there was such an increase in reactors is not fully understood. It is thought that the cessation of TB testing during the foot and mouth outbreak in 2001 was a significant factor. The gamma interferon test was introduced the following year, which has a higher sensitivity than the test used previously. This, coupled with an intensification of TB testing and ‘zero tolerance’ approach to overdue tests in 2005, may have had an impact on the number of reactors.

John lists translocation of cattle and amplification within herds (which tend to be larger than they were 30 years ago) as factors that may have contributed to the increase in reactors. He believes that there is a disproportionate focus on wildlife reservoir of infection.

Badgers, John says, are one piece of the puzzle, but controlling badger populations is not the key to controlling bovine TB in the UK. The TB spoligotype known in the south-west appeared in Cumbria in 2001; as John points out, “it wasn’t badgers who walked up the M5 and M6”. In his view, it is important that a comprehensive strategy is in place, taking other factors into account, such as movement, trade, biosecurity, accurate testing, disclosing reactors and rapid removal.

In his current work, John notes “inconclusives and reactors sadly are almost an everyday occurrence”. Nevertheless, he adds, “Let’s not forget that, although we are seeing more reactors being taken (and that’s probably because we are testing a lot more frequently and being more aggressive with the interpretation of the testing to try and beat it back), we are making some good inroads with a reduction in the number of herds that have gone down with TB or remain under restriction in some areas.”

How OVs have had to adapt

Farmers whose herds are affected by TB often suffer a great financial blow and OVs aren’t always best equipped to deal with the personal effects that a TB diagnosis can have on a farmer. “The emotional impact is very easy to underestimate,” says John. “In some instances, people have their life’s work – genetically speaking – taken away.”

The role of the OV has adapted to changing circumstances extensively over the past 30 years. “They almost wear two hats – they’re a private veterinary surgeon and an official agent of the government in delivering the test. I think the messages are far better delivered, and I think Defra’s survey of livestock keepers some time ago showed the value of having that local dialogue with clients,” John says.

There are ways of working through an outbreak with a farmer, and John reiterates the importance of OVs talking their clients through the situation and the options available to them. He thinks it’s “very important to have that sort of dialogue with the case vet from APHA as soon as possible after disclosure and restriction.

“One of the frustrations clients express to me is that when we turn up a reactor, we issue the forms, and we say, ‘Somebody will be in touch with you from APHA’ – and that doesn’t always happen immediately. It is important to have that sort of mechanism – often clients want answers. How is it going to progress? When are the reactors going to be removed?”

Cases should be managed on an individual basis. John thinks many of his practice’s clients would be content with the advice they receive, but also that “we, as a profession, need to be aware of support mechanisms that are out there for farmers to contact should we feel the need to direct them that way”. In difficult situations, he recommends pointing clients to the Farming Community Network and the various support services available.

Looking forward, John is hopeful about progress in dealing with bTB in Great Britain: “The thing with TB is that we always get spikes – some months or quarters you think, ‘We’re not winning any battles’, but the general trend over time is reduction. As time goes on and we learn more about the disease, we will have more tools to enable us to push back.”

Senior Editor at Veterinary Practice

Jennifer Parker, BSc, PgDip, MSc, is a science writer and editor. She studied zoology, endangered species re-covery and palaeoanthropology in the UK. Jennifer was Senior Editor of Veterinary Practice magazine for almost three years; she left the publication in October 2019 to move abroad and pursue a freelance writing career.

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