Prevalence of Mycobacterium avium in slaughter pigs based on serological monitoring results and bacteriological validation.

Mycobacterium avium (MA) is a potential food safety hazard in pigs. Blood samples of slaughtered pigs in the Netherlands and Germany were tested for the presence of MA antibodies to estimate the serological prevalence in the tested population. In the Dutch and German population 1.0% and 1.7% samples were positive, and 0.5% and 17.4% of the herds were at risk for having a MA infection respectively. The validity of the applied MA-ELISA was evaluated under field conditions. The specificity of the MA-ELISA was high (>98.4%). The average herd sensitivity was 18%. In the affected herds on average 50% of the animals were tested bacteriological positive for MA. It can be concluded that serological screening for the presence of MA antibodies is capable of identifying pig populations that are at risk for a MA infection.