Peri-anal abscess--the relationship between peri-anal abscess, hepatitis B and sexual behavior.

Twenty-two patients with a peri-anal abscess or peri-anal fistula were studied selectively for the presence of HBsAg and anti-HBs. In 14 male and 8 female patients studied, the incidence of anti-HBs was 6 and of HBsAg 1. Positive findings occurred only in European male patients who invariably showed frequent homosexual contacts. It is concluded that, in homosexual patients with peri-anal abscess, the presence of HBsAg and anti-HBs should be determined as a matter of routine and all preventive measures should be taken for possible contamination with hepatitis B virus until proven negative.