A COMMUNITY-WIDE OUTBREAK OF HEPATITIS-A - RISK-FACTORS FOR INFECTIONAMONG HOMOSEXUAL AND BISEXUAL MEN

PURPOSE: To assess risk factors for hepatitis A infection among homose xual and bisexual men during a community-wide outbreak of hepatitis A in New York City. PATIENTS AND METHODS: Twenty-five homosexual acid bi sexual men, 20 to 49 years of age with hepatitis A identified from hea lth department surveillance data (cases) were compared with 42 homosex ual and bisexual men of similar age distribution who were seronegative for hepatitis A virus and Identified from private physician offices ( controls). Odds ratios (OR) were determined for acute hepatitis A infe ction according to demographics, numbers of sexual partners, frequency of specific sexual behaviors, and self-reported human immunodeficienc y virus status. RESULTS: Cases had more anonymous sex partners (0 to 1 partner versus >1 partner) than controls during the 6 weeks before il lness onset (OR = 4.4, 95% confidence interval [CI] 1.4 to 14.4). Case s were more likely than controls to have engaged in group sex (OR = 3. 8, 95% CI 1.1 to 12.6). Among specific sexual behaviors examined, oral -anal intercourse (oral role) and digital-rectal intercourse (digital role) with anonymous sex partners were more commonly reported by cases than controls (OR = 9.7, 95% CI 1.2 to 78.7 and OR = 2.6, 95% CI 1.0 to 7.4, respectively). Multivariate analysis showed that >1 anonymous sex partner, group sex, oral-anal intercourse, and digital-rectal inte rcourse were associated with illness in models controlling for duratio n of sexual activity. Because these variables were highly correlated, independent risk could not be evaluated in a single model. CONCLUSIONS : Hepatitis A infection among homosexual and bisexual men is associate d with oral-anal and digital-rectal intercourse, as well as with incre asing numbers of anonymous sex partners and group sex. These findings reinforce the importance of developing educational activities for homo sexual and bisexual men that focus on risk reduction for hepatitis A a s well as other sexually transmitted diseases spread via the fecal-ora l route.