title: [Factors associated with HIV and syphilis infection among men who have sex with men blood donors in Shenzhen].
abstract: OBJECTIVE
  To investigate the distribution and factors associated with HIV and syphilis infection among Men who have sex with men blood donors (MSMBD) in Shenzhen.
  
  
  METHODS
  A total of 813 MSMBD were recruited using snowball sampling and respondent driven sampling from 2009 to 2012 in Shenzhen. Questionnaire-based interviews were conducted on a one-on-one basis. Data were collected including socio-demographic information, HIV testing history, self-identified sexual orientation, role in homosexual behavior, information about having sex with male sexual partners in the past six months and information about having sex with female sexual partners in the past six months.5 ml blood samples were taken and tested for treponema pallidum and HIV antibodies. Comparisons of syphilis and HIV infection among different years were analyzed by the Cochran-Armitage trend test. Factors associated with syphilis and HIV infection were analyzed by the univariate logistic regression and multivariate unconditional logistic regression.
  
  
  RESULTS
  The prevalence of syphilis, HIV, and syphilis-HIV co-infection among 813 participants were 22.0% (179/813), 8.0% (65/813), and 4.2% (34/813), respectively. In the multivariate logistic regression analysis, ever tested for HIV (versus without HIV testing history, OR (95%CI) = 0.369(0.213-0.641)) will decrease the risk of HIV infection among MSMBD in comparison with never tested for HIV (OR (95%CI) = 0.37 (0.21-0.64) ); having five or more anal sexual partners in the past six months and co-infected with syphilis will increase the risk of HIV infection among MSMBD in comparison with having 0-1 sexual partners (OR (95%CI) = 2.04 (1.03-4.06) ) and negative syphilis (OR (95%CI) = 4.52(2.64-7.73)), respectively, bisexual orientation, having 2-4 anal sexual partners and having five or more anal sexual partners in the past six months, using condoms not for every act of anal sex, co-infected with HIV will increase the risk of syphilis infection among MSMBD in comparison with homosexual orientation (OR (95%CI) = 1.60(1.12-2.27)), having 0-1 sexual partner in the past six months (OR (95%CI) = 1.77 (1.09-2.87) and OR (95%CI) = 1.84(1.09-3.08) ) , using condoms for every act of anal sex (OR (95%CI) = 1.61 (1.10-2.36) ) and negative HIV (OR (95%CI) = 4.02 (2.33-6.96)), respectively.
  
  
  CONCLUSIONS
  The prevalence of HIV and syphilis among MSMBD in Shenzhen are much higher with complex influence factors. The relevant government should pay great attention to it and ensure the blood safety.
authors.affiliation: Sexually Transmitted Disease Control and Prevention Department, Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen, Guangdong 518020, China.
authors.forename: Yumao
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Email: lh_0805@hotmail.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Song
authors.forename: Fuchang
authors.initials: F
authors.lastname: Hong
mesh_terms: D000328:Adult; D001782:Blood Donors; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D015658:HIV Infections / Q000097:blood / Q000453:epidemiology*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013587:Syphilis / Q000097:blood / Q000453:epidemiology*