Saturday, January 21, 2006

PCR diagnostics.

Former Shadow minister, Owen Paterson MP recently visited the USA, and in particular the state of Michigan to see for himself the response of other countries to a tuberculosis reservoir in wildlife, and in particular the strides made with Polymerase Chain Reaction on-farm diagnostic testing.

In an article (in FWi) written by Owen Paterson, he describes his visit:
"....The USA shows clearly that Bovine TB can be eradicated in cattle and wildlife by a combination of the following:
* Fast, accurate and modern diagnosis.
* Rigidly enforced but workable pre-movement testing and movement restrictions.
* Vigorous, if unpopular, campaign to bear down on disease in wildlife.

It must be emphasised that only a combination of all of these will work. Picking only one or two of them will not eliminate the disease. ..."

"...... new PCR kits, developed for the army in Iraq, are as small as a briefcase and there is absolutely no practical reason why tests could not be done on the environment in the environment from the back of a truck in less than two hours. A well equipped laboratory could do over 1000 a day. They believe that PCR would work on material around setts. It was felt that Ben Bradshaw’s letter to me was quibbling....(US vets were) ... utterly astounded by the grotesque dimensions of the TB epidemic in the UK. .... there was clearly no doubt that we should be pressing the Government to trial PCR technology as we have already proposed. "Read in full

The great and the good gather this week to defend their budgets. Dr. Cheeseman from 'Badger Heaven' other wise known as Woodchester Park, a four year 'trial' into badger BCG (already undertaken in Ireland) and John Bourne to defend - the indefensible Krebs trial. Interestingly Krebs was described by Cheeseman this week as 'rigourous and robust'. As 57 % of the traps were 'interfered with' and 12% went AWOL, and trapping only accounted for between 30 - 60 % of the target group anyway, one may wonder just how bad it would have to get, for the good doctor to consider a 'trial' weak and flawed? But such is Defra's beneficial largesse, that it seems nobody is prepared to forge ahead with tomorrow's technology to identify infected animals and their environment. Australia used PCR in 1997, Michigan in 2001 - but the UK? Forget it, we'd rather kill 30,000 cattle a year, allow a notifiable zoonosis to devastate Britain's badgers and then spill over into - well anything that crosses its path actually.

This country will not wake up, until tuberculosis is reported in domestic pets.
But from February 20th, that will happen. Tuberculosis becomes notifiable in all mammalian species. Bring on the cats.


Anonymous said...

PCR not ready yet!

this from 'Hansard' at

15 Dec 2005 : Column 1443

and the charges. I did not quite understand it—perhaps someone else may like to put it to me again during this session—but the testing will be a private transaction between a farmer and a vet. Certainly, DEFRA has no intention of profiteering or charging more than would otherwise be charged. Indeed, our objective is to roll out testing by lay testers, which should significantly reduce the cost to farmers.

The hon. Gentleman asked about gamma interferon and PCR. It is important to stress that nothing that we are announcing today means that we can take the foot off the accelerator in terms of the work that is already going on to develop a vaccine both for badgers and for cattle, or to develop a PCR. He is not quite right to suggest that we have already got a reliable PCR test for bovine TB in badger setts. That work will continue, as will the rolling out of the gamma interferon test, which is an important adjunct to, not a replacement for, the skin test.

Matthew said...

The problem with UK scientists is that until they themselves have used, developed or even trialled technology, thinking 'outside the box' is a no go area.

PCR was available and offered to the UK in March 2001 just days after FMD was found, by its developer in the States, the late Professor Fred Brown. Defra refused it, preferring instead to cull 12 million cattle and sheep.

As we pointed out in the post, PCR has been in use in Australia and the States for several years, for speeding up bacterial samples in cattle lesions, yet the UK is just preparing to repeat that exercise.

The fact that the UK now has the product flying a Union flag, developed and paid for by Enigma Diagnostics, which is funded by a consortium including venture capitalists but also Porton Down and VLA (Veterinary Laboratories Agency) the taxpayer by any other name - should be a cause for rejoicing. But again, feet are dragging and there would appear to be absolutely no intention to use this amazing technology for the purpose of identifying tuberculosis in the environment.

One might ask why not?

Anonymous said...

The Krebs trial wasn't as unsuccessful as you thought. As somebody who worked on it for 7 years, the numbers of badgers caught were quite substantial. The damage sustained was high; however, it only resulted in alternative catch strategies being deployed, with the end result being more badgers than originaly estimated being caught.

Matthew said...

When you say "The damage sustained was high;" we assume you mean damage to traps?
Delighted to hear that common sense prevailed and more of the target group was caught - by whatever method.
In time, as more data on Krebs is released the result of this will feed through, but for the present only the first year is being flagged up with clearance rate of 21% (in Proactive) and a transfer of outbreaks to contiguous farms of 29%.

The second year figures, presumably as population density and perturbation decreased, was more encouraging. Farmers in proactive areas having had the full 5/6 year treatment are mainly clear which is good. Meanwhile the bulk of the breakdowns are now outside Krebbs areas.

What is very demoralising is that so much expertise like yours, is under notice to quit as of March 31st. We need that expertise and Defra's overview of the Tb situation in a given area. But at present we feel the minister has no intention at all of facing the problem.