Crack use, sex trading and male bisexual behavior: Implications for HIV diffusion

Background: In HIV research, gay and bisexual men are often lumped together as men who have sex with men (MSM). However, they differ in important ways that may influence their risk for HIV infection and transmission. Moreover, there may be variations among men who have sex with men and women (MSMW or bisexual men) that may affect their risk of HIV infection and their potential to serve as a bridge for the sexual spread of HIV from MSM to women and the general population. Methods: MSMW (n=164) were recruited using respondent driven sampling in central North Carolina between 2005 and 2008. Cluster analysis was used to classify these men into clusters based on their drug use, involvement in sex trading, sexual identification and homelessness. Additional analyses were conducted to examine the relationships between cluster membership and risk behaviors with men and disclosure of bisexual behavior to women. Results: Cluster analysis resulted in a three cluster solution. The clusters varied significantly by age, race, homelessness, sexual identification, involvement in the sex trade, HIV status and drug use. In multivariate models, cluster membership was a significant predictor of insertive but not receptive anal intercourse. Cluster membership was also a significant predictor of disclosure of bisexual behavior to women. Conclusions: These findings suggest that there are important differences among MSMW that influence the risk of HIV infection and transmission and their potential to serve as a bridge for the sexual diffusion of HIV from MSM to women and the general population.