Light shed on Bovine TB Spread
The University of Liverpool has revealed research which suggests that the failure of the current bovine tuberculosis (TB) eradication programme could be in part due to a parasitic infection that hinders the tests used in cattle to diagnose the disease.
In a study of more than 3,000 dairy herds in England and Wales, scientists at Liverpool - working with the Agri-food and Biosciences Institute, Stormont, and University College Dublin - found that liver fluke infection reduces the sensitivity of skin tests used to diagnose bovine TB.
In 2011, the bacterial disease resulted in the slaughter of roughly 25,000 cattle - costing more than £90 million. Solutions for the eradication of the disease have included badger culling but now the new research, published in Nature Communications, suggests the spread of disease may also be attributable to the common liver parasite.
Professor Diana Williams, from the University’s Institute of Infection and Global Health, said: “Tests to diagnose bovine TB rely on inflammation of the skin in response to injected TB proteins, but if the animal also has liver fluke infection, this inflammation is suppressed, reducing the detection of bovine TB. This means that cattle infected with both liver fluke and bovine TB may not be identified by the current bovine TB surveillance scheme in operation in the UK.”
Professor Matthew Baylis, also from the Institute, explained: “The potential consequences of these findings are that infected cattle can continue transmitting BTB to other cattle, to wildlife reservoirs and, if they are moved from their farm of origin, to other areas of the country. This may in part explain the continuing spread of BTB and the failure of the current eradication programme in the UK.”
It is hoped that this research can help improve diagnosis of bovine TB and speed up eradication of the disease from the UK.
Defra has published guidance for the vet sector ahead of a proposed UK-EU Sanitary and Phytosanitary agreement.
