title: HIV incidence and associated factors in a cohort of men who have sex with men in Nanjing, China.
abstract: BACKGROUND
  Many surveys conducted in recent years reported the increasing trend of HIV infection among men who have sex with men (MSM), but limited data exists on HIV incidence by cohort study in China.
  
  
  METHODS
  A 6-month prospective cohort study was conducted. A total of 397 MSM found HIV seronegative at baseline study were followed-up for 6 months starting from May 2007 and re-evaluated seroconversions of HIV at 6 months. Questionnaire interviews were conducted to collect information about risk behaviors.
  
  
  RESULTS
  Of the 397 MSM who were found seronegative at the baseline study, 286 (72.0%) received the HIV antibody testing at month 6; 7 of them showed HIV seroconversions, yielding an incidence of 5.12 per 100 person-years. Significant predictors of seroconversion (Poisson regression analyses) included duration being MSM >10 years (relative risks [RR] = 3.08, 95% CI: 1.53-6.20), recruiting male sex partner mostly at saunas (RR = 2.35, 95% CI:1.09-5.08), positive syphilis diagnosis made at the baseline study (RR = 2.82, 95% CI: 1.31-6.09), having multiple male sex partners in the last 6 months (RR = 2.54, 95% CI: 1.18-5.49), having at least 1 casual male sex partner in the last 6 months (RR = 2.17, 95% CI: 1.00-4.70), and having unprotected anal sex with a regular male sex partner in the last 6 months (RR = 2.22, 95% CI: 1.10-4.49).
  
  
  CONCLUSIONS
  The incidence of HIV among MSM is very high; many new infections would hence occur in China. Effective interventions are warranted. The risk factors reported in this study give some insights for designing relevant prevention programs.
authors.affiliation: Jiangsu Provincial Central for Disease Control and Prevention, Nanjing, Jiangsu, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Yang
authors.forename: Chun
authors.initials: C
authors.lastname: Hao
authors.forename: Xiping
authors.initials: X
authors.lastname: Huan
authors.forename: Hongjing
authors.initials: H
authors.lastname: Yan
authors.forename: Wenhui
authors.initials: W
authors.lastname: Guan
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Xu
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Weiming
authors.initials: W
authors.lastname: Tang
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.forename: Joseph T F
authors.initials: JT
authors.lastname: Lau
mesh_terms: D000328:Adult; D044466:Asian People / Q000706:statistics & numerical data*; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D005500:Follow-Up Studies; D006679:HIV Seropositivity / Q000453:epidemiology* / Q000523:psychology; D007722:Health Knowledge, Attitudes, Practice; D006293:Health Promotion; D018451:Homosexuality, Male / Q000523:psychology / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D059012:Lost to Follow-Up; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012747:Sexual Partners / Q000523:psychology; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014505:Urban Population