[Behavior and influencing factors of HIV infection among men who have sex with men only and men who have sex with both men and women in Shandong province].

This study aimed to examine the demographic characteristics, HIV related knowledge and behavior, correlates of bisexual behavior and status of HIV infection among men who have sex with men only (MSMO) and men who have sex with both men and women (MSMW) in Shandong province. According to the requirements from "National HIV/AIDS sentinel surveillance program" , a cross-sectional survey was conducted to collect information on demographics, sexual and drug use behaviors, and HIV-related services among MSM in nine sentinel surveillance sites from April to July in 2018. Blood samples were drawn for serological tests on both HIV and syphilis antibodies. A total of 3 474 participants were included in this study. Related information on these participants would include: average age as (31.66±9.01) years; 35.06% (1 218) married or cohabiting with a woman, 50.52% (1 755) had college or higher education, 80.11% (2 783) self-identified as gays and 14.22% (494) self-identified as bisexual men,16.87% (586) ever having sex with woman in the past 6 months, 10.51% (365) ever using drugs. HIV and syphilis prevalence rates were 2.99% (104/3 474) and 2.76%(96/3 474). Through multivariable logistic models, MSMW were more likely to be ≥35 years of age, local residents, self-identified as heterosexual/bisexual/uncertain, ever having commercial sex with man but less likely to consistently use condoms in the past 6 months, less using internet/dating software to find male sex partners and less using drugs. There was no significant differences noticed in the following areas: number of sexual partners in the last week, condom use in the last six months with commercial sex partners, with HIV or syphilis infection and self-reported history of STD in the past year between MSMO and MSMW (>0.05). HIV-infected MSM were more likely to have the following features, ≥45 years of age, non-local residents, finding male sex partners from the bothhouses, park/toilets or from the internet/dating software, also less likely to consistently use condoms in the past 6 months, using drugs or with syphilis infection. High prevalence of bisexual behavior as well as higher risk of HIV infection were noticed among MSM in Shandong province. It is important to strengthen related surveillance and effective intervention programs for MSM with different characteristics in Shandong province.