An outbreak of bovine tuberculosis in two herds in south west Scotland--veterinary and human public health response.

Abstract

Although the incidence of bovine tuberculosis in UK cattle has declined markedly, outbreaks still occur. There is often confusion as to how veterinary and human public health agencies should interact in such circumstances. We report an outbreak of bovine tuberculosis which occurred in South West Scotland in 1992. The outbreak, which affected two cattle herds, and potentially involved 17 humans, was discovered when visible tuberculous lesions were found at routine post mortem examination of a calf. Investigation of animals and humans, exchange of information between human and veterinary public health agencies, and subsequent control measures followed the guidance of a recently produced protocol. Tuberculin testing of other animals in the index herd revealed 11 reactors. Testing of the herd of origin of these animals revealed 84 reactors out of 261 animals. Movement restrictions were placed on the index herd, and all the animals in the herd of origin were slaughtered. The humans were screened primarily by history and tuberculin skin testing. Eleven of them required chest X-rays (all were normal) and six were given prophylactic chemotherapy with isoniazid. Nobody developed clinical illness. The use of an agreed protocol proved to be very helpful to both human and veterinary public health agencies in the investigation and control of an outbreak of bovine tuberculosis. There is a clear need for better human screening tests.