Over the last twenty years we have listened in disbelief and increasing anger, to the prattling of those inhabiting their setts in the Westminster bubble, hell bent on finding that huge hidden reservoir of cattle TB which is driving the epidemic in this country, while ignoring the blindingly obvious.
Having trousered £1m in 1997, they employed one of the most 'political' scientists - [link] on the planet to prevaricate for another decade. And have wrapped the UK's primary wildlife reservoir of zoonotic Tuberculosis up in its grade 1 listed Ancestral home with ultimate protection. So, as they busily skip towards their protected pensions, what can we remind them of as another new year breaks?
Here's a few points for starters.
We are hearing some alarming 'factoids' about the universally applied intradermal skin test. But apparently only applicable in certain areas of England, Wales and Ireland it seems. In the rest of the world, it works just fine. Now if this internationally used skin test was missing X per cent of infected cattle in parts of Great Britain (take your pick on what figure is doing the rounds) but let's settle on 20 per cent, then eventually, all these disease riddled animals would end up in abattoirs. That's what happens. And they would go down the line past a Meat Hygiene operative, trained to look for evidence of - tuberculosis.
So how many do they find? Defra reported in 2014:
Between 2009 and 2013, over 11.1 million cattle were recorded as slaughtered in 313 slaughterhouses in GB. During this period 7,370 samples with lesions suspicious of bTB were submitted to AHVLA by meat inspection teams of the Food Standards Agency (FSA) leading to an overall rate of 0.66 submissions per 1,000 animals slaughtered.
M.bovis was identified in 5,366 [of those] samples.Full report on this link - [link]
But 5,366 out of 11.1 million cattle with culture positive evidence of zTB is not 20 per cent missed, or even 2 per cent. Its just under 0.05 per cent. Some reservoir. Some lie.
And don't mention the Isle of Man - [link] a lump of rock in the Irish sea, from which you can see if not touch, parts of Ireland, Wales and England: enjoying the same weather, geology, cattle husbandry and testing. But no TB and no badgers. Maybe it is the TT races? But then correlation is not causation, is it?
So as more severe cattle measures rain down on herds unfortunate to live in the areas of England frequented by endemically infected badgers, will they work? Will testing all breakdown herds twice under severe interpretation, using more GammaIFN (with a specificity of around 65 per cent) and very little movements except direct to an abattoir, work?
So a message to all you bright young things, who think this is a new idea, it is not. -[link] It was done with bells on in Cornwall in the 1970s by a DVM called William Tait who operated fierce and brutal cattle carnage. And repeated from 1988 - 1992 by Liam Downie - [link] in the Republic of Ireland.
Predictably, the results of both were a futile and expensive embarrassment. Except that our lot seem hell bent on repeating them. Why?
Which brings us around to the latest guff to hit the cattle industry. The Berlin wall which Defra have erected around the best piece of pure science to be available to us for a long while.
A screening test to find infected badgers - [link] something which we have always been assured wouldn't happen.
But having accepted this validated test in 2011, repeated it to find its best operational protocol in 2014, Defra then proceeded to ignore that protocol in a blinded trial commissioned in 2015.
And still one test passed 4 out of 5 strict criteria with flying colours, when offered genuinely positive (spiked) samples. So what was left? Professor Wellington's PCR test was said to be 'borderline' on group specificity.
And would thus leave a possible heap of falsely accused, but very dead badgers.
We could remind readers that gammaIFN has a specificity around 65 per cent when used on cattle, leading to many false positives, but let that pass.
The blinded trial used single samples, so how did they arrive at a group figure? We suspect that they 'modeled' it back from a single sample / badger. But PCR is not a test which can be 'modeled'. It is DNA.
Think paternity tests and Forensic Science. No interpretation, just a yes or a no - but not the milkman.
Now being the cynical lot that we are at blogger headquarters, we see this as an evasion of responsibility.
Because if a Grade 3 zoonotic pathogen is found, then the responsibility for its removal and eradication is not that of farmers, running around the countryside within a mythical boundary, trying to shoot 70 per cent of the possible carriers. That responsibility is Defra's, and must be operated under strict bio hazard conditions.
And that is a responsibility they would rather not accept.
Our co-editor has succinctly offered a quote by Upton Sinclair which fits the bill quite neatly;
"It is difficult to get a man to understand something, when his salary depends upon him not understanding it."Quite.
No comments:
Post a Comment