Actinobacillus pleuropneumoniae serotype-2 antibodies in sow colostrum in Finnish pig-health-scheme herds.

A direct ELISA with phenol-extracted antigen for Actinobacillus pleuropneumoniae serotype 2 was developed. The test was specific when tested with rabbit antisera prepared against different A. pleuropneumoniae serotypes. It had better-than-moderate repeatability and it made a clear distinction between positive and negative samples. A total of 5477 colostrum samples from breeding sows from herds participating in the Finnish Pig-health Scheme were tested using the ELISA test. A total of 1307 positive samples were found in 129 out of 154 herds, thus indicating that most of the disease-control herds in Finland are infected with A. pleuropneumoniae serotype 2. These infections were almost entirely subclinical.