Prevalence of Actinobacillus pleuropneumoniae Infection in Hunted Wild Boars (Sus scrofa) in Germany

Actinobacillus pleuropneumoniae is an important pathogen of the porcine respiratory tract. Subclinically and chronically infected pigs may enter a permanent carrier state, harboring A. pleuropneumoniae in lungs or tonsils. Despite the enormous role of A. pleuropneumoniae in domestic swine production, no published data about prevalence and distribution of A. pleuropneumoniae infections in wild boars (Sus scrofa) are available. Antibodies against A. pleuropneumoniae have been detected in serum of wild boars from Slovenia. The aim of the present study was to evaluate A. pleuropneumoniae infection status in wild boars in Germany. Tissue samples from lungs and tonsils of 5:31 wild boars from 52 hunts dining the hunting seasons 2004-05 to 2006-07 were examined for A. pleuropneumoniae by polymerase chain reaction (PCR). Although gross pathologic lesions typical for pleuropneumonia were not detected, 35.8% of the wild boars were PCR-positive. Tonsils were involved in 94.3% and lungs in 15.5%. Actinobacillus pleuropneumoniae infection prevalence increased with age and body weight. Further research is needed to understand the involvement of different A. pleuropneumoniae serotypes and to understand the interrelationship of A. pleuropneumoniae infection between wild boars and domestic pigs.