Prevalence of Naturally Acquired Agglutinating Antibodies Against <i>Aeromonas salmonicida</i> in Hatchery Trout in Central Pennsylvania

Abstract

A survey for naturally acquired antibodies against Aeromonas salmonicida in brook and brown trout in central Pennsylvania hatcheries showed great variation in the percentage of reactive individuals (0.8–87%) within 24 populations. Antibodies were not detected in fish less than 12 months old, and the percentage of serologically reactive individuals increased with the age of the population. Prevalence of antibodies in yearling trout populations in which furunculosis was epizootic was about twice as great as in fish experiencing enzootic furunculosis.