High HIV incidence and prevalence and associated factors among young MSM, 2008.

Objective: To estimate HIV prevalence, annual HIV incidence density, and factors associated with HIV infection among young MSM in the United States.

Design: The 2008 National HIV Behavioral Surveillance System (NHBS), a cross-sectional survey conducted in 21 US cities.

Methods: NHBS respondents included in the analysis were MSM aged 18-24 with a valid HIV test who reported at least one male sex partner in the past year. We calculated HIV prevalence and estimated annual incidence density (number of HIV infections/total number of person-years at risk). Generalized estimating equations were used to determine factors associated with testing positive for HIV.

Results: Of 1889 young MSM, 198 (10%) had a positive HIV test; of these, 136 (69%) did not report previously testing HIV positive when interviewed. Estimated annual HIV incidence density was 2.9%; incidence was highest for blacks. Among young MSM who did not report being HIV infected, factors associated with testing HIV positive included black race; less than high school education; using both alcohol and drugs before or during last sex; having an HIV test more than 12 months ago; and reporting a visit to a medical provider in the past year.

Conclusion: HIV prevalence and estimated incidence density for young MSM were high. Individual risk behaviors did not fully explain HIV risk, emphasizing the need to address sociodemographic and structural-level factors in public health interventions targeted toward young MSM.