A Prospective Cohort About Incidence Of HIV Among Men Who Have Sex With Men

Objective Through a prospective cohort study among 731 HIV-negative men who have sex with men(MSM)in Zhejiang Province to understand the follow-up rate and factors associated with retention among MSM,understand the level of HIV incidence and related factors,and understand the situation and influencing factors of unprotected anal sex between MSM and their casual homosexual partners,provide the theoretical basis for formulating HIV intervention strategies for MSM.Methods Prospective cohort was conducted among MSM recruited through the voluntary counseling and testing(VCT)clinic of the Center for Disease Control and Prevention(CDC)and the free online application platform created by the local nongovernmental organization(NGO)“Sunshine Coast” in Shaoxing with informed consent.Questionnaire survey was conducted via the free online application platform.The questionnaire included sociodemographic characteristics,knowledge of HIV prevention and treatment,sexual behavior characteristics,awareness of HIV status between sexual partners,access to Internet information and HIV testing experiences.MSM recruited through CDC regularly go to CDC for HIV screening test;MSM recruited through NGO were regularly received HIV rapid testing kits by mail and performed the test by themselves,and the test results were sent back in the form of photos within a week.The follow-up survey were conducted every six months,including questionaries and HIV test.MSM were received messages or telephone call 4 weeks before and after the schedule visit.HIV positive MSM were referred to the local CDC for HIV confirmation test.We determined the MSM who were HIV negative in the baseline study had turned to be positive during the follow-up visits was new HIV infection.New infections will be referred to the local disease control center for HIV confirmation test and the observation is terminated.After that we will use a case epidemiological questionnaire to understand their sexual behavior characteristics in the past year.Results 1.A total of 747 HIV positive MSM were enrolled in the cohort study,baseline study found 16 MSM who were HIV positive and the prevalence of HIV was 2.14%(95%CI:1.10%～3.18%).Excluding 16 HIV positive MSM,731 MSM were included in the cohort.2.638 and 572 MSM were retained at 6-month and 12-month follow-up visits,and follow-up rate were 87.28% and 78.79% respectively.Multivariate logostic analysis revealed that AIDS related knowledge awareness(OR=4.17,95%CI:2.18～7.97),no unprotected anal sex with casual homosexual partners in the past 6 months(OR=3.113,95%CI:2.03～4.79),low infection risk of selfevaluation(OR=1.98,95%CI:1.15～3.44)were significantly associated with 12-month follow-up.3.Among 731 MSM tested negative for HIV antibody,7 participants seroconverted for HIV infection during 438.48 PY at the first follow-up,HIV incidence was 1.60/100PY(95%CI:0.42～2.78).2 participants seroconverted for HIV infection during 315.77 PY at the second follow-up,HIV incidence was 0.63/100PY(95%CI:0.25～1.51).A total of 9 participants seroconverted for HIV infection during 754.25 PY after 12-month follow-up,HIV incidence was1.19/100PY(95%CI:0.42～1.97).The multivariate Cox regression model analysis indicated that there was statistical difference between HIV incidence and having unprotected anal sex with casual homosexual partners in the past 6 months.4.The baseline study found that 289 participants(39.54%)reported haing unprotected anal sex with casual homosexual partners,and 241 participants(32.97%)had had unprotected anal sex with casual homosexual partners in the past 6 months,108 participants(14.77%)had unprotected anal sex with casual homosexual partners in the past 6 months.Multivariate logostic analysis revealed that nevr ask about the HIV status of casual homosexual partners(OR=2.15,95%CI:1.28～3.60),watching sexual culture images with sexual partners(OR=1.78,95%CI:1.11～2.86),having no history of HIV detection(OR=1.84,95%CI:1.15～2.94)were the influence factors of having unprotected anal sex with casual homosexual partnersConclusions 1.The follow-up rate were 87.28% and 78.79% at 6-month and 12-month follow-up visits respectively.Multivariate logostic analysis revealed that AIDS related knowledge awareness,no unprotected anal sex with casual homosexual partners for 6 months,low infection risk of self-evaluation were significantly associated with 12-month follow-up.2.The HIV incidence of 731 MSM tested negative for HIV antibody was 1.19/100 PY,and the HIV incidence level is relatively low,but the HIV incidence level at 6-month follow-up was higher than late observation.The HIV incidence of MSM who having unprotected anal sex with casual homosexual partners in the past 6 months was much higher than MSM who not having unprotected anal sex with casual homosexual partners in the past 6 months.3.The rate of MSM having unprotected anal sex with casual homosexual partners is high.Whether MSM are willing to investigate HIV status of sexual partners,the surrounding social environment when watching sexual culture images,accessible HIV testing services may affect whether MSM have unprotected anal sex with with casual homosexual partners.