Neighborhood and network influences on HIV and STIs among young men who have sex with men

Black young men who have sex with men (YMSM) show alarming disparities in the prevalence of HIV infections, yet studies have shown they do not report higher levels of HIV risk behaviors compared to white YMSM. Increasingly, research is suggesting that structural and network-level phenomena may explain these disparities. One possible explanation links together the effects of racial homophily in sexual networks, patterns of racial segregation by neighborhoods in many large cities, and neighborhood differences in HIV prevalence. To study the effects of having sex partners from high HIV prevalence neighborhoods we linked together epidemiological data on numbers and rates of HIV diagnoses by neighborhood area with egocentric network data from 175 YMSM (Age: 17 - 23; Race: 14% White, 54% Black; 21% Latino, 11% other). Network study participants completed assessments of individual risk factors of HIV/STIs, biological assessment of HIV/STIs (10.9% positive), and neighborhood residence for each of their sexual partners. Participants reported a total of 3,390 network members (including sexual and social network members), with each participant having on average 14.7 core support network members and 8.0 sex network members. There was significant homophily of sexual partners by race, and number of black alters was significantly associated with HIV status controlling for participant race. Epidemiological data and network data demonstrate that rates of HIV infection significantly differ by neighborhood area. We will describe the incremental effect of HIV prevalence in neighborhoods of residence for network sex partners compared to self-reported HIV risk behavior.