Dear Friends,

I believe I have read estimates of the sensitivity of the SICCT ranging from approximately 65% to 90%.

Having tested cattle in west Donegal for 25 years between 1982 and 2008, I formed the opinion that these were underestimates.

I can recall just two occasions when, following trace-backs, Department of Agriculture officials contacted me to tell me that an animal I had tested clear had subsequently shown a TB lesion at slaughter. I think one had last been tested by me approximately a year before and subsequently shown up in a number of different herds outside my area, and that the other had originated in a herd of one of my clients and left that herd approximately two years before its slaughter.

Mind you, conversations with many of my colleagues working in the Republic of Ireland, in Northern Ireland and in Wales led me to the opinion that my own testing may have been carried out more scrupulously than the average. The fact that, last I heard, my disclosure of inconclusive reactors was approximately nine times higher than the average rate at which my County Donegal colleagues found them supported this opinion. You see, apart from wishing to do the job right, and to be seen to wish to do so, I used to believe that the all data I assembled, even those referring to skin measurements in cattle which passed the test, might one day be subjected to useful statistical analysis such as the authors of this paper appear to have attempted.

That said, I spent the year of 1985 in Australia. Despite having to test vast numbers of cattle fast under extremely difficult conditions and using what might seem a cruder and less sensitive caudal fold test than the SICCT, Australia managed to eliminate bovine TB. How? The elimination was turned over to the farmers, to the industry from government, as I understand it. It had the trust and the good will of the farmers. As in the US, bounties were paid to meat inspectors for finding TB. And they did not have infected badgers or possums to deal with.

For reasons outlined in what could be considered a controversial link included in my disclosure of possible competing interest below, I believe the disturbance of badgers in the UK and in Ireland has been the main driver of TB in cattle, and that that disturbance, perturbation, has been caused by the clearing of forests, the construction of roads and other developments, but not least by government trials such as the Four Areas Project in Ireland and the RBCT in Britain, along with copycat badger "cullings" by farmers.

Every good wish.

Tom Kelly,
Escondido,
California.
tomkellyvet@gmail.com