title: [Study on the incidence of HIV and associated risk factors through a prospective cohort among men who have sex with men in Beijing, China].
abstract: OBJECTIVE
  To investigate the dynamic change and associated risk factors of HIV sero-conversion rate in Beijing.
  
  
  METHODS
  809 sero-negative men who have sex with men (MSM) were recruited in the cohort from August to December in 2009. HIV sero-antibody, medicinal examination and behavior questionnaire interview were carried out every six months.
  
  
  RESULTS
  962 MSM with overall baseline prevalence of HIV infection as 6.34% (61/962) together with 809 sero-negative MSM, were enrolled in the cohort. Of the 809 sero-negative participants, 95.1% (769/ 809), 85.5% (692/809) and 71.0% (574/809) of them were retained in the 6-month, 12-month and 18-month follow-up visits, with 19, 29 and 17 of them became HIV sero-conversion at 6-month, 12-month, and 18-month follow-up visits and the HIV incidence rates appeared to be 5.47, 12.37 and 6.86 per 100 person-years respectively. The HIV incidence was 7.59 per 100 person-years in the 18 months follow-up visit. Factors including: younger than 25-years old (HR = 2.32, 95%CI: 1.39 - 3.87), having more than 8 MSM partners (HR = 2.50, 95%CI: 1.49 - 4.20), less than 2000¥ every month income (HR = 1.76, 95%CI: 1.05 - 2.95), having more than 4 homosexual partners in the last six months (HR = 3.50, 95%CI: 2.11 - 5.81), showing phimosis and redundant prepuce (HR = 2.47, 95%CI: 1.50 - 4.07) as well as positive syphilis test (HR = 2.62, 95%CI: 1.53 - 4.49) etc., were significantly associated with HIV incidence.
  
  
  CONCLUSIONS
  High HIV incidence was shown among MSM in Beijing and had spread fast in this population, calling for more favorable prevention measures to be taken.
authors.affiliation: Chaoyang Center for Disease Control and Prevention, Beijing 100021, China.
authors.forename: Dong-Liang
authors.initials: DL
authors.lastname: Li
authors.forename: Yan-Jie
authors.initials: YJ
authors.lastname: Gao
authors.forename: Ming-Run
authors.initials: MR
authors.lastname: Yu
authors.forename: Xue-Ying
authors.initials: XY
authors.lastname: Yang
authors.forename: Shu-Ming
authors.initials: SM
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.forename: Ying-Jie
authors.initials: YJ
authors.lastname: Liu
authors.forename: Shu-Lin
authors.initials: SL
authors.lastname: Jiang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zhang
authors.forename: Dong
authors.initials: D
authors.lastname: Xiao
authors.forename: Li
authors.initials: L
authors.lastname: Yan
authors.forename: Gui-Yan
authors.initials: GY
authors.lastname: Jiang
authors.forename: Hong-Ping
authors.initials: HP
authors.lastname: Wang
authors.forename: Zhen-Hai
authors.initials: ZH
authors.lastname: Zhou
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Ruan
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Shao
authors.forename: Feng-Ji
authors.initials: FJ
authors.lastname: Luo
mesh_terms: D017677:Age Distribution; D002681:China / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology*; D006679:HIV Seropositivity; D018451:Homosexuality, Male / Q000523:psychology* / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D012309:Risk-Taking; D012725:Sexual Behavior / Q000523:psychology / Q000706:statistics & numerical data; D012747:Sexual Partners; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D013587:Syphilis / Q000175:diagnosis; D055815:Young Adult