Objectives: To access the prevalence of HIV infection and the associated factors among urban MSM in China.
Methods: Participants were recruited using respondent driven sampling and snowball sampling method in Beijing, Harbin, Zhengzhou and Chengdu city. A face-to-face questionnaire was administrated to collect relevant demographic and ethological data; 5 ml venous blood sample was taken from each subject to measure HIV antibody in serum (samples were first screened by colloidal gold, latex chromatographic and double-antigen sandwich ELISA method, positive samples were further confirmed by immunoblotting method). The characteristics of HIV infection was described and the risk factors were analyzed.
Results: A total of 1864 MSM were recruited and the prevalence of HIV was 6.7% (125/1864). It was 9.5% (24/252) among MSM older than 39 years and it was 1.9% (2/105) among those less than 20 years old. The prevalence was 8.4% (31/371) among MSM with junior level education and was 4.8% (41/858) among those with college level education. It was 10.3% (35/340) among MSM with sexual partner old than him for over 10 years while it was 5.0% (58/1168) among those having sexual partner within 10 years older. The prevalence of HIV infection was 8.9% (61/695) among MSM with unprotected receptive anal sex and it was 5.5% (64/1169) among those without unprotected receptive anal sex. The risk factors independently associated with HIV infection included being older than 39 years (OR = 6.5, 95%CI: 1.5 - 28.7), with junior or lower level education (OR = 1.8, 95%CI: 1.2 - 2.7), having sexual partner older than himself for over 10 years (OR = 2.1, 95%CI: 1.3 - 3.3) and having unprotected receptive anal intercourse (OR = 1.6, 95%CI: 1.1 - 2.4).
Conclusion: MSM had a high rate of HIV infection. Older age, lower level education, having older sexual partner and unprotected receptive anal intercourse were related to HIV infection.