DEFRA steps up TB detection as new cases continue to fall

Junior DEFRA minister Ben Bradshaw today (Thursday, 10 August) announced plans to enhance detection of bovine tuberculosis infected cattle with the introduction of the gamma-interferon test as an adjunct to the skin test.

From October the gamma-interferon test will be used under specific circumstances where it is thought it will deliver the greatest benefit.  When combined with the skin test accuracy of detection is much improved to 97%.

DEFRA also published a report by chief veterinary officer Debby Reynolds who was asked by ministers to investigate the apparent fall in new herd cases of TB since the beginning of the year. 

While she acknowledged that the recent change in tuberculin solution used in the test from one made at the Veterinary Laboratories Agency, Weybridge, to one manufactured in Holland may account for a small percentage change in detection, it was not plausible that it could account for the 19% drop seen up to 30 June. 

Further analysis of the trend and greater consideration of other factors over a longer period of time would be necessary, she said.

The announcement comes just a day after DEFRA published provisional statistics for the number of new cases of TB up till the 30 June this year.  The trend seen since the beginning of the year continues, but the size of the fall is slowing.

Up until the end of June there were 3538 new cases of TB compared with 4356 for the same period last year – a drop of 19%. 

Consequently the number of cattle slaughtered due to TB fell 32% from 16,972 to 11,534.  The West of England, the worst affected region of Great Britain, contributed 64% to the total number of slaughtered cattle. 

However, the fall in new cases does not suggest the disease is in retreat, but, instead, spreading at a slower rate.