Actinobacillus suis infection in pigs in Australia.

This is the first report of the isolation of Actinobacillus suis in association with significant disease among preweaned pigs in Australia. Sudden deaths occurred in preweaned piglets at one facility and enlarged joints, particularly the stifles and tarsi, occurred at another. Isolates with the biochemical phenotype and apx genotype profile of A suis were cultured from affected piglets. Both facilities were of high health status and one had undergone a recent depopulation, disinfection and sow repopulation process. Reviewing initial reports of A suis disease overseas, it is apparent that outbreaks occurred sporadically in various locations, with disease occurring among the herds involved for some months only, before development of immunity. A suis disease is now considered an emerging disease on high health status farms.