Hepatitis and other sexually transmitted diseases in gay men and in lesbians.

The prevalence of most sexually transmitted diseases is disproportionately increased in gay men and paradoxically decreased in lesbian women. The spectrum of diseases seen in gay men include a variety of enteric infections including hepatitis A, shigellosis, salmonellosis, Campylobacter enteritis, amebiasis, giardiasis, and enterobiasis as well as the more common sexually transmitted diseases. Hepatitis B is endemic in gay male populations. The patterns of sexual behavior are the major factors contributing to this unique epidemiology and pathology. Increased sexual activity explained by the unrestrained cultural expectation of maleness, the functional overlap during sex between the genital-urinary and gastrointestinal systems, and anonymous sexual activity are all significant epidemiologic components.