“The pilot project demonstrated that a two stage PCR test on camelid clinical samples has the potential to detect Mycobacterium bovis with reasonable sensitivity. Samples were taken post-mortem from 21 alpacas with gross lesions of tuberculosis: most of the alpacas selected had severe lesions. Fifteen faeces samples and ten nasal swabs were positive.
Samples that were negative in these PCR tests were from alpacas with less severe pathology”.
The full text of this announcement can be seen on the website of The Alpaca TB Support Group who commissioned the study. (Click the left hand buttons for more information on PCR including its current commercial uses by AHVLA)
Using a combination of faecal and nasal material, this project showed PCR's ability to detect m.bovis in 17 out of 21 animals (80.9 percent) and importantly, gave no false positives.
We have supported PCR as a diagnostic tool for years; and in previous postings brought other major successes to your attention, including earlier this year, this project which detected m.bovis in badgers. We are puzzled why no media hacks have grabbed these 'good news' stories. But then it is easier to cut and paste press releases than to dig into what is really going on. We missed this validated, peer reviewed and published paper into PCR and badgers and we also missed this little gem.
In a project undertaken by a Nottingham University School of Biological Sciences student, Derrick Fall, looked into using PCR in abattoirs to detect bTB. In this case on sheep. This is probably not the time to remind readers that in 1997, Professor John Bourne announced quite confidently to his farmer and veterinary audience that ‘sheep did not contract TB’. As in so many things, the man was quite wrong. But we digress ….. Commercial drug manufacturers MSD (Merck, Sharpe & Dohm) Animal Health offered this student a Bursary to investigate abattoir lesions in sheep. And his conclusion was that bTB was now present in the UK sheep flock. We may return to this project, if we can have sight of the Veterinary Record report on it.
The Camelid Tb Support and Research Group have had no such industry funding and indeed the brickbats keep flying, especially from within the alpaca community. Such breeders cannot really want to risk losing hundreds of animals, possibly exporting bTB and moving it around the country on the strength of a rubbish skin test, can they? That was a rhetorical question, by the way.
The results of this Proof of Concept project on alpacas are extremely encouraging, especially where bTB is advanced. AHVLA now wish to undertake a further screening of samples where bTB lesions are less pronounced. This will investigate the level at which detection of bTB using PCR is possible. Samples are held ready to use and the PCR screen of these could be completed within a month. Donations towards this second phase would be most welcome. A 'donate' tab is available at the alpaca TB support group's website, www.alpacatb.org. When the second phase is completed, results will be published together with those from the initial screen which we report today.
As we have said before, if nothing else, this small group has shown the farming industry how to commission PCR as a diagnostic tool for bTB. It is no use asking Defra to do it; they have no cash and no interest in stopping this gravy train of misery which employs so many hangers on. But AHVLA now have to stand on their own commercial feet, and if cattle, sheep or pig farmers and owners of other mammals susceptible to bTB want better diagnostic tools, then they only have to ask - and then pay up. Even the Badger Trust could put their hand further into Brian May's deep pockets and commission a wider screening of badger setts. That's if they have any interest at all in cleaning up the
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