Hepatitis C virus infection in a male homosexual cohort: risk factor analysis.
BACKGROUND: Hepatitis C virus (HCV) infection is a major cause of morbidity throughout the world. Parenteral exposure to infected blood accounts for the majority of cases. Sexual transmission is suggested by the higher prevalence of infection in sex workers and homosexual men. Sexual practices which contribute to HCV infection need to be identified. METHODS: The social and medical history, and HCV serostatus of 1058 homosexual men in the Pittsburgh arm of the Multicenter AIDS Cohort Study were analysed. Multivariate analysis was used to determine risk factors for HCV seropositivity. RESULTS: 31 men were HCV seropositive by enzyme immunoassay and recombinant immunoblot assay (2.9%). They were more likely to be HIV seropositive (39%) than the HCV seronegative men (19%). Needle sharing and illegal drug use were the most important risk factors for HCV seropositivity. Statistically significant sexual factors (p < 0.05) included a history of syphilis, rectal gonorrhea, anal insertive intercourse with ejaculation, and douche or enema use before anal receptive intercourse. The number of sexual partners was not a significant risk factor. CONCLUSIONS: HCV infection is associated with specific sexually transmitted diseases (STDs) and sexual practices in the male homosexual population. The evidence of high risk behavior should be incorporated into ongoing educational efforts to decrease the incidence of STDs.