HIV incidence and cohort retention among men who have sex with men in Hangzhou, China A prospective cohort study

Prospective cohort studies have been conducted to estimate HIV incidence among men who have sex with men (MSM) in first-line megacities cities (>10 million residents) in China, but few in the second-line large- or middle-size cities. This study was to investigate HIV incidence and cohort retention among MSM in a second-line city Hangzhou in eastern China. A total of 523 HIV-seronegative MSM were recruited during September 2014 to September 2015, and were followed up prospectively at 3, 6, 9, and 12 months. Questionnaire interviews were conducted, and laboratory tests were performed to evaluate baseline syphilis infection and HIV seroconversions. Chi-square test and logistic regression model were used to identify factors associated with cohort retention rate and syphilis prevalence. Of 523 participants, 137 (26.2%) completed 6-month follow-up, and use of Internet for recruiting study participants (vs other recruitments: adjusted odds ratio [AOR]=0.5; 95% confidence interval [CI]: 0.3-0.8) and being homosexual (vs heterosexual or bisexual: AOR=0.6; 95% CI: 0.4-0.9) were associated with lower cohort retention. The overall HIV incidence during 12 months of follow-up was 6.6 per 100 person-years (95% CI: 3.4-9.8/100 PY). The prevalence of syphilis at baseline was 6.5% (95% CI: 4.4%8.6%), and disclosing sexual orientation (AOR=0.4, 95% CI: 0.2-0.9) was associated with lower risk of syphilis infection. HIV is spreading rapidly among MSM in the second-line Chinese city. Effective interventions are needed to target this population in both first-line megacities and second-line large and middle-size cities.