Understanding disparities in HIV infection between black and white MSM in the United States.

OBJECTIVE: We evaluated several hypotheses for disparities in HIV infection between black and white MSM in the United States, including incarceration, partner HIV status, circumcision, sexual networks, and duration of infectiousness. DESIGN: The 2008 National HIV Behavioral Surveillance System (NHBS), a cross-sectional survey conducted in 21 US cities. METHODS: MSM were interviewed and tested for HIV infection. For MSM not previously diagnosed with HIV infection, we used logistic regression to test associations between newly diagnosed HIV infection and incarceration history, partner HIV status, circumcision status, and sexual networks (older partners, concurrency, and partner risk behaviors). For HIV-infected MSM, we assessed factors related to duration of infectiousness. RESULTS: Among 5183 MSM not previously diagnosed with HIV infection, incarceration history, circumcision status, and sexual networks were not independently associated with HIV infection. Having HIV-infected partners [adjusted odds ratio (AOR) = 1.9, 95% confidence interval (CI) = 1.2­3.0] or partners of unknown status (AOR = 1.4, CI = 1.1­1.7) were associated with HIV infection. Of these two factors, only one was more common among black MSM ­ having partners of unknown HIV status. Among previously diagnosed HIV-positive MSM, black MSM were less likely to be on antiretroviral therapy (ART). CONCLUSION: Less knowledge of partner HIV status and lower ART use among black MSM may partially explain differences in HIV infection between black and white MSM. Efforts to encourage discussions about HIV status between MSM and their partners and decrease barriers to ART provision among black MSM may decrease transmission.