HIV prevalence and sexual behavior in a cohort of New York City gay men (aged 18-24).

An ethnically diverse cohort (n = 174) of New York City gay men (aged 18-24) was studied to determine human immunodeficiency virus (HIV) prevalence and to document sexual behavior patterns. Blood tests of 87 men showed an HIV prevalence of 9%, but only 3% of the previously tested men (n = 77) reported knowledge of a positive test result at baseline interview. An annual HIV seroconversion rate of 2% was observed. Ethnic minority men were more likely to test HIV positive. In addition, the median number of both sexual episodes and sex partners, and the proportion of men who engaged in anal intercourse, increased significantly from 1990 to 1991. During this 2-year period, 91% of the men engaged in unprotected receptive oral intercourse, and 37% engaged in unprotected receptive anal intercourse.