Monday, December 21, 2015

The end of another year.

It's now 12 years since we posted most of the 538 Parliamentary questions, which formed the basis of this site in 2004. It is also over 100 years since Professor Koch did his experiments with m.bovis, and instigated the first postulates of disease transmission, which relied on a set of principles, rather than absolute proof.

In between then and now, this country had almost eradicated zTB from its cattle herds, only to see a resurgence in the mid 1980s from a wildlife reservoir it seems soooo reluctant to touch. And hasn't touched at all since a £1m bung to the Labour government in 1997.

Not unsurprisingly,  in the last couple of decades, main setts in England have increased by 103 per cent. How do we know? Because almost two years ago now, this article - [link] was published by Fera, which told us. Fera have also confirmed that in areas of endemic TB, about 50 per cent of the badgers are infected.

Apparently, we have a 25 year plan, but from where we stand, that seems long on cattle measures and short on anything to do with a wildlife reservoir of disease. But then, it's what Professor Bourne manipulated - [link] his team to deliver, almost 20 years ago. His idea was to let farmers knock off a few (a very few ) badgers to get them to accept cattle measures. Most of which, by next year, will be in place.

Meanwhile the Chinese whispers surrounding a DNA screening test for infected badgers get louder. Who has the megaphone we have yet to find out, but they are dead wrong. - [link]

Even when offered half the optimum number of samples, one tenth of the optimum number of bacteria and using a third of the background prevalence of disease, this test performed very well, meeting 4 out of 5 of Defra's criteria. The one on which it was 'borderline' was Specificity. That is the number of false positives any test gives;  which while not upsetting many people when it comes to tests used for cattle, appears to give Defra's mandarins indigestion when applied to badgers.

But how do they calculate DNA? Obviously the acronym PCR (Polymerase Chain Reaction) fuddles their collective brain, so we'll stick to Deoxyribonucleic Acid which is the long word for DNA. An acronym most people have heard of and trust.
Think paternity tests, forensic science, Silent Witness and TV murder mysteries.

And the only way a DNA sample (PCR is DNA fragments) can give a false positive is if the sample (or those playing with it?) is corrupt or contaminated. It's a straight 'Yes' or 'No'. But what you cannot do is 'model' it to give stupid results, if you want to trash the whole idea. Neither can you take specificity of one test on one badger and model it back to a group. Warwick's badger DNA test is a group test, relying on 20 samples taken from a group latrine - the one nearest the sett. And used as instructed and validated, it works.

So as this year draws to a close, what have we achieved? Just three small pilot cull areas with some dubious input data on existing herd breakdowns - [link] which are proving difficult to substantiate - one way or the other. Two of these pilots end next year, with nothing in place after that. Meanwhile, we have several mini cull areas awaiting Natural England's attention. They'll have to move quickly to catch up on Fera's 103 per cent increase in main sett populations.
And, we hear, possibly some mini T-Bags. Local discussion groups which are to feed 'information' - as yet unspecified - up to the big TBEAG and thus to government.Who can then file it.

 Inevitably, we also have another raft of cattle measures to look forward to. Two tests at severe interpretation for any herd in the high risk area which has a breakdown, regardless of the cattle post mortem results. And a post movement test for cattle moving out of that area and not slaughtered within 120 days.

The one good thing which happened this year, is that the daft idea of vaccinating badgers - [link] has hit the buffers. But with cynicism born of years of practice, we expect some other inventive  prevarication to replace it - bio-garbage security being one possibility.

Meanwhile zoonotic Tuberculosis marches eastwards and north on four small paws, at a rate of knots. And there is nothing at all in the way of targeted wildlife management for these areas, only a nervous wait until they achieve High Risk status. And then they can try to comply with Natural England's mathematical carnage of a 70 percent cull on 90 per cent of land, in 6 short weeks. And pay for it..

Our grateful thanks to all our contributors around the world, and a very merry Christmas from us all at blogger headquarters.

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