Sexual mixing patterns and partner characteristics of black MSM in Massachusetts at increased risk for HIV infection and transmission.

Black men who have sex with men (MSM) are at increased risk for HIV infection in the United States compared to other MSM. The aim of this study was to investigate Black MSM's sexual mixing patterns and partner characteristics in relation to sexual risk taking, as a possible explanation for this observed increase in HIV incidence. Between January and July 2008, 197 Black MSM were recruited via modified respondent-driven sampling and completed optional pretest and post-test HIV serological testing, counseling, and a demographic, behavioral, and psychosocial assessment battery. Bivariate and multivariable logistic regression procedures were used to examine predictors of risky sex across partner types. Overall, 18% of the sample was HIV-infected; 50% reported unprotected intercourse with men, 30% with women, and 5% with transgender partners. Fifty-three percent identified as bisexual or straight, although all reported oral or anal sex with another man in the prior 12 months. Significant predictors of engaging in at least one episode of: (1) serodiscordant unprotected anal sex (UAS) with a male partner in the past 12 months: individuals at risk for social isolation (AOR = 4.23; p = 0.03), those with unstable housing (AOR = 4.19; p = 0.03), and those who used poppers at least weekly during sex (AOR = 5.90; p = 0.05); (2) UAS and/or unprotected vaginal intercourse with a female partner in the past 12 months: those with unstable housing (AOR = 4.85; p = 0.04), those who used cocaine at least weekly during sex (AOR = 16.78; p = 0.006), being HIV-infected (AOR = 0.07; p = 0.02), and feeling social norms favor condom use (AOR = 0.60; p = 0.05); (3) UAS with the participants' most recent nonmain male sex partner: use of alcohol and drugs during last sex by participant (AOR = 4.04; p = 0.01), having sex with a Hispanic/Latino male (AOR = 2.71; p = 0.04) or a Black male (AOR = 0.50; p = 0.05) compared to a White male, and lower education (AOR = 1.31; p = 0.02). Findings suggest that sexual risk behaviors of Black MSM differ across partner type and by the characteristics of their sexual networks and that this subpopulation of MSM are at high risk for HIV acquisition and transmission. Effective prevention strategies need to address the distinct sexual and behavioral risk patterns presented by different sexual partnerships reported by Black MSM.