Further Aspects of VPH

Has state-sponsored badger-culling caused very widespread increases in Tb in cattle in GB and Ireland?

I have read that, during a certain ten-year period - and one in large measure overlapping, I believe, the ISG's ten-triplicate, badger-culling trial - the incidence of bovine tuberculosis in Great Britain increased seven-fold.

I have also read that, following the "getting underway" of nation-wide badger-culling in the Republic of Ireland in "1997-98," a 54% increase in the number of tuberculin-reactors slaughtered in Ireland was recorded in 1998 as compared with the 1997 figure, which had been not much different from the figures recorded annually from 1993. This increased level was sustained in 1999, according to my source, the offical figures given me by DAFF, the Irish department of agriculture, when the increase was approximately 55% above the 1997 level. After that, there was some apparent tailing off, but there has meanwhile also been a steady decline in the Irish national herd since about then, too, so that the absolute decline in reactor numbers may conceal a real increase of some 15-20% in the incidence of reactors from 1997 to 2006, for instance, in marked contrast to the impression given here, http://www.agriculture.gov.ie/press/pressreleases/2007/may/title,13476,en.html , and especially in the opening sentence of the sixth paragraph of that press release of May 2007.

To my knowledge, no figures have yet been published indicating the numbers of reactors found in the buffer zones of the Irish Four Areas Project, carried out between 1 Sept. 1997 and 31st August 2002, a fact I have long found disturbing. If anybody knows any such figures, whether published or not, could they please enter a source for them here?

I have many reasons to suspect a causal link in both cases, the GB and the Irish, that much of the bovine tuberculosis increases followed as a direct result of the culling operations, the effects of which have been far more widespread than officially/publicly explored, investigated, suspected or acknowledged.

I would be very keen to read others' opinions on this matter, please.

Tom Kelly, MVB, MRCVS, "Inatosha," 965, Luna Vista Drive, Escondido, California 92025, USA. tomkellyvet@gmail.com ph: 001 760 291 70 66

With reference to http://www.irishveterinaryjournal.com/Links/PDFs/Peer/Peer_December_06.pdf , I understand that the following letter to the Editor of the Irish Veterinary Journal has been published in this month's journal (May, 2010):

Dear Editor,

As a practitioner who had spent a quarter of a century tuberculin-testing cattle in west Donegal, including herds located in what formed the Removal, Reference and Buffer Areas of the FaP (or Four-areas Project), I studied with great interest the paper, A case study of bovine tuberculosis in an area of County Donegal, Ireland, which appeared in Volume 59 (12) : December, 2006 Irish Veterinary Journal.

I believe that the the outbreaks of btb in that cluster of 19 herds bore temporal and spatial characteristics typical of badger-related incidents. Further, they exhibited patterns of infection suggestive of tuberculosis in cattle which have been exposed to infected badgers and/or their infected excreta/discharges. This is in contrast to the much lower-grade outbreaks one now associates with bought-in and with bovine-to-bovine infections. If btb reappears on any Irish farm nowadays, given the findings of that same FaP, I suggest that the first residue to suspect is the badger residue. I therefore cannot understand - much less agree with - the reasoning of the authors in their preamble:

"The increased number of BTB breakdowns during the fifth year most likely occurred because of the recrudescence of infection, herd-to-herd transmission and, to a lesser extent, purchase of infected cattle. Infected badgers remain as a possible but less likely source of infection, especially as an explanation for the cluster of infected herds."

The following passage of the Discussion baffles me.

"In addition to herd-to-herd spread, the possible role of infected badgers cannot be disregarded. All the ER76 forms indicated that land fragments grazed by cattle (in herds with multiple ‘standard reactors’ during the fifth year) had evidence of badger activities. Four herds had active setts on their land and, in all the remaining farms, badger latrines or badger passes were identified and confirmed by a veterinary inspector. However, only four badgers were caught (from eight setts) and only one (25%) badger was diagnosed as M. bovis positive at histology examination. This level of infection does not differ from the 26.1% prevalence in badgers in the other three reference areas of the FAP. Thus, even though the role (infected) badgers can play in BTB in cattle (O’Connor and O’Malley, 1989; Dolan, 1993; Martin et al., 1997; Olea-Popelka et al., 2005; Griffin et al., 2005) is recognised, the authors do not think the outbreaks during the fifth year should be attributed primarily to badgers."

A reported haul of just four badgers from eight active setts, and particularly in November, a month so favourable to snaring, begs the question, "What happened to their fellows?"

"We have no evidence of excess TB in badgers, nor of a high density of badgers in this area. In such circumstances, transmission of BTB from a single, infected and highly-active, badger to a number of herds does not seem biologically-plausible."

The absence of evidence in such circumstances is certainly NOT evidence of absence, and, contrary to the reasoning of the authors, does nothing to exonerate the missing badgers.

Finally, the absence of any reference in this paper to the strain-typing of M. bovis isolates from any/all reactor cattle in Co. Donegal, and certainly from those grazed or housed in the areas of study, as well as of any badger-derived isolates, is a conspicuous omission.

Yours very sincerely,

Tom Kelly, MVB, MRCVS.

Thomas P. Kelly Escondido, California USA mobile: (760) 291-7066 (dialing from Ireland... 001 + 7602917066)