Unintentional HIV exposures from young men who have sex with men who disclose being HIV-negative.

Objective: To evaluate the proportion of new sexual partners potentially exposed to HIV from young MSM who disclosed being HIV-negative.

Design: Cross-sectional, observational study of men aged 23-29 years recruited from randomly sampled MSM-identified venues in six US cities.

Methods: Participants were interviewed and tested for HIV. Analyses were restricted to MSM who reported last testing HIV-negative and having one or more new partners in the prior 6 months.

Results: Of 1701 MSM who reported a total of 11 793 new partners, 1075 (63%) disclosed being HIV-negative to 4253 (36%) new partners before having sex with them for the first time. Of disclosers, 352 (33%) reported last testing HIV-negative > 1 year before their interview and 80 (7%) tested HIV-positive (HIV-infected unaware). By race, 24% of black, 5% of Hispanic, and 3% of white disclosers tested HIV-positive. Of the 4253 new partners, 296 (7%) were partners of the 80 HIV-infected unaware MSM. By race, 22% of new partners of black, 3% of new partners of Hispanic, and 4% of new partners of white MSM, were partners of HIV-infected unaware MSM who disclosed being HIV-negative.

Conclusions: Many new sex partners may be unintentionally exposed to HIV from young MSM, particularly those who are black and who disclose being HIV-negative based on an earlier test. Young MSM should test for HIV more frequently and consistently use condoms with all partners unless they are in a mutually monogamous relationship in which both partners have tested HIV-negative at least 3 months since their last potential HIV exposure.