Sunday, May 07, 2017

A catch up conversation.

As time passes and more UK cattle reactors are piled up dead, we note that research into zTB, m.bovis and its screening tests is repeated around the world.

We are grateful for the input of a vet from New Zealand, a country which has, with farmer co operation and a great deal of government oversight, achieved TB free status in a relatively short time. In the UK, we are just beginning that laborious process with voluntary farmer involvement in small areas, their non-voluntary cash up front and no government oversight whatsoever.

Frequently we hear criticism of the skin test so questioned the NZ vet, where it used as a single jab (non comparitive) in the caudal fold.

Below is our conversation:
"Interesting re the skin test - I had an opinion that UK should use the caudal fold Bovine tuberculin only test (CFT) as the screening test - it is quicker, safer, easier and cheaper, cheaper, cheaper.

I thought the last factor would have helped or the safety issue. The other key thing with skin testing is that it is a herd test dependent on the testing being done correctly. I had one good vet say to me once if the CFT was used "at least the test would be done properly". The CFT is simple and so much easier to get right, quickly and safely (with good facilities - that should be enforced to receive subsidy payments [not a politically correct term but that's my opinion on what they are])".
Now it's popular for Defra to blame veterinary practice in testing, blame the product, the farmer or the man in the moon. In fact anything but a 'wildlife'interface. So we double checked with a UK vet, with acres of experience of testing - and results - over the last 40 years. This was his comment in reply to the comment above:
"We use the CCT because of serious problems with non specific infection in the past.

It worked well and actually eradicated TB from all the farms in the UK – but not all at once, sadly. Certainly, in the late 60s and early 70s, TB was at a very low level, even in Glos and Cornwall.

I feel that if badger controls (Protection of Badgers Act) had not come in in the 70s things might have been different. This was at a time when it (testing) was certainly not applied uniformly well by the vets carrying out the test, but this was well enough, it seems.

It is not the test that is the problem and slaughtering large numbers of probably uninfected cattle, which must happen with the Gamma ifn test, is a good way of damaging our farming industry. That’s all.

We know that removing the wildlife reservoir works. It is everything to do with the politics."
But on specificity, (false positives) New Zealand had problems too it seems and their vet commented that there is...:
" ... plenty of non-specificity in NZ as well. Many UK Vets have the misconception that there is not. We have Johne's, Avian TB, environmental mycobacteria. The CFT is a more sensitive test, but not as specific. BUT, in lower risk areas the gamma can be used as a secondary test (especially effective when using the most specific antigens).
The accuracy of any screening test is always a trade off between Sensitivity (finding disease or exposure to bacteria which may cause disease) and Specificity (false positives and dead victims)
 In the UK, we note  that  Specificity of 100 per cent is the prime aim in any test for badgers, with the Sensitivity (ability to find disease) dropping to mid 50 per cent or less in many screening tests, in favour of not harming the hair of one badger's head.

Conversely, our politicians seem hell bent to unleash any of a number of secondary tests on our cattle with the opposite effect while leaving a burgeoning wildlife reservoir to upspill.

 So what drove New Zealand to get a serious handle on their zTB problems? One word. Trade.
The NZ vet comments:
"After seeing TB control in NZ and TB "control" in the UK firsthand - with 14+ and 9+ years in the respective countries - TB is much simpler to control than many in the UK would have you believe given the political will and finance. The non-tariff trade barriers that are rearing their heads now for UK were what prompted NZ into a fully committed approach to TB control back in the 1990's."
We have warned of possible Trade implications - [link] before. In fact the European Union drew up such veterinary import / export documents to cover such eventualities in 2004 - [link] when Russia was rattling her sabres. And make no mistake, separating the country into small patches just wouldn't cut it.

The paperwork dictates a dedicated collection chain for all bovine products which must be TB free from birth to plate, thus another 'Beef Ban' is likely.

New Zealand began its eradication process with just farmer involvement but the process stalled and government took over. So what have we been offered in the UK?
Volunteer scattered groups of farmers, under the control of an organisation - [link] which in its right hand, offers farmers grants to provide 'Badger Gates' and in its left, oversees small culls, having made the protocol for such population control as difficult as possible.

Our NZ commentator had this to say:
"Dad's Army" is a good description of how politicians have allowed (legal) badger control in England. I believe that optimum wildlife control to achieve eradication needs to be centrally co-ordinated and controlled; probably funded by Government (whose ignorance and negligence have allowed the problem to escalate and spread geographically) and industry (who would be the predominant beneficiaries)"

We are often told that 'farmer co-operation' is vital for disease control. That is true, but that description should not be confused with farmers in suits, sitting behind the revolving doors of Defra's London headquarters, playing 'politics' with our industry.

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