Erysipelas in poultry. Prevalence of serotypes and epidemiological investigations.

Eight different serotypes of Erysipelothrix rhusiopathiae were isolated from 39 outbreaks of erysipelas in poultry, serotypes 1, 5, 6 and 9 being most prevalent. More than one serotype was demonstrated in five outbreaks. Only White Leghorns were affected as far as erysipelas in chickens is concerned, and 94% of the flocks were kept on sloping wire floors of the Pennsylvania system. No relationship between serotype, host predilection and virulence was observed, nor was there a seasonal distribution. The epidemiological and preventive aspects of the present findings are discussed.