Defra under fire after rejecting new TB evidence

A report in the online science journal Nature Communications has supported long-standing suspicions that liver fluke, a common condition, interferes with the standard skin test for TB and could cause a large number of false negatives.

The Badger Trust said the findings meant undetected carriers in cattle could be doing the damage that badgers have been blamed for. But because it is new evidence, it may not be admissible when the trust argues in court that the Secretary of State at Defra, Caroline Spelman, acted unreasonably by organising a badger cull this autumn.

Liverpool University academics Diana Williams and Matthew Baylis, working with Lancaster University, picked up on experiments by a government-funded research agency in Northern Ireland, the Agri-Food and Biosciences Institute, working with University College Dublin.

The experiments showed that animals injected with both fluke and BTB had a reaction to the BTB tests which was so diminished it was likely that in some circumstances it could be missed.

The Lancashire team checked the field statistics and found a possibly significant under-reporting of BTB from herds in fluke-heavy areas. They estimated that up to a third of infected animals could be being missed.

But Defra scientists noted that the Northern Ireland research did not actually produce a false negative and that the Lancashire research was making assumptions about “holes” in the BTB map which could be explained in other ways. A spokesman said: “No test for bovine TB is 100 per cent but we use the best available.”

Professor Williams, lead author of the Nature report, said Defra was “burying its head in the sand”.