HIV and syphilis prevalence among young migrant men who have sex with men (MSM) by different sampling methods in China: Implications for HIV/STD surveillance and prevention

Background & Objectives: One of the challenges in HIV/STD surveillance and prevention targeted at MSM in China is the potential selection bias. Despite the consistently documented differences in demographic characteristics and sexual risk among MSM recruited by different sampling methods, systematic variations in HIV and syphilis infections and demographic and behavioral factors by different sampling methods have not been investigated to date. We examined these variations among MSM who were recruited using four different sampling methods. Methods: A total of 307 young migrant MSM (aged 18-29 years) were recruited through venue-based sampling, internet, community outreach, and social network in Beijing, China, in 2009. They completed a self-administered cross-sectional survey and provided blood specimens for HIV/STD testing. Results: Among MSM recruited from venues (e.g., MSM bars), internet, community outreach, and social network, HIV prevalence were3.4%, 7.8%, 5.1%, and 5.8%, respectively; syphilis prevalence were 13.8%, 11.8%, 21.8%, and 36.2%, respectively; consistent condom use were 62.1%, 42.2%, 43.6%, and 46.4%, respectively. Additionally, MSM from venues were significantly more likely to use illicit drugs (8.6%) compared to MSM recruited by other means (1.0%, 2.6%, and 1.4%). Significant differences were also found in such individual characteristics as age, education, and duration in Beijing. Conclusion: Significant differences exist among MSM recruited by different sampling methods including HIV and syphilis prevalence, consistent condom use, substance use, and various individual characteristics. The results underscore the importance of using multiple sampling methods to reach MSM from diverse backgrounds and in different social segments in both HIV/STD surveillance and intervention.