Bisexual behavior and infection with HIV and syphilis among men who have sex with men along the east coast of China.

This study examined the correlates of bisexual behavior and infection with HIV/syphilis among men who have sex with men only (MSM-only) and those who have sex with both men and women (MSMW) in Shandong, China. Cross-sectional surveys probed sociodemographic information, sexual and drug use behaviors, knowledge, and use of prevention services; blood samples were tested for HIV/syphilis status. Of 2996 participants, 39.5% acknowledged being MSMW; 60.5% being MSM-only; 2.5% were HIV-infected with similar rates for MSMW (2.5%) and MSM-only (2.6%); 5.5% syphilis-infected with comparable rates for MSMW (5.6%) and MSM-only (5.5%). In multivariable models, MSMW were more likely than MSM-only to be older, local residents, recruited from outdoor cruising area, drug users, and less likely to have used a condom during last anal sex with a male partner. HIV-infected MSMW were more likely to have syphilis and other sexually transmitted diseases (STDs) and less likely to have received peer education. HIV-infected MSM-only were more likely to be older, nonlocal residents, and have syphilis and other STDs. MSMW with syphilis were more likely to be recruited from Jinan, Qingdao, and Zibo (versus Yantai), infected with HIV, and less likely to have received lubricant promotion. MSM-only with syphilis were more likely to be recruited from Jinan and Qingdao (versus Yantai), drug users, infected with HIV, and have had sex with male partners in the past 6 months. High prevalence of bisexual behavior and HIV/other STDs with common unprotected sex and multiple sexual partners among Shandong's gay community revealed in this study highlighted the importance of bisexuals as a potential epidemiologic bridge. Further research is needed to investigate the impact of bisexual behaviors on population transmission.