Prevalence of classical swine fever, Aujeszky's disease and brucellosis in a population of wild boar in Switzerland.

During two survey rounds of a national surveillance system for infectious diseases in wild boar in Switzerland, each lasting four months from November to February, between 2001 and 2003, 1949 blood samples and 62 tissue samples from the spleen and 50 from the reproductive organs were collected from hunted wild boar. The survey was designed so that freedom from infection could be detected with a probability of 95 per cent at a threshold prevalence of less than 1 per cent for classical swine fever and Aujeszky's disease and less than 1.5 per cent for brucellosis. There was no serological evidence of classical swine fever or Aujeszky's disease, but brucellosis due to Brucella suis biovar 2 was confirmed serologically and by bacterial isolation.