[An outbreak of bovine tuberculosis on a dairy farm]

An outbreak of bovine tuberculosis on a dairy farm is described. Following intradermal tuberculination 84 animals out of 111 animals older than 6 weeks had a positive reaction. Of the 34 adult sheep one gave a positive reaction. All animals on the farm were taken over for destruction by the Animal Health Centre. The source of the infection could not be established although there was a strong suspicion that the importation of three older dairy cows had introduced the infection on the farm. A further investigation was done on 45 farms. Two of these farms were infected by buying animals from the dairy farm in question. During the investigations the possible transmission of the infections to people who were in close contact to the infected animals was also investigated. From 35 examined persons 5 had a positive Mantoux-reaction. The outbreak coincided with a political discussion concerning the abolishment of the periodical tuberculination on dairy farms. Since 1 January 1993 the surveillance of bovine tuberculosis in the Netherlands is done by import control and findings in slaughter-houses combined with a good identification system. It is stressed that the examinations of the lymph glands in the slaughter-houses require the necessary attention.