title: Incidence of HIV and Syphilis among Men Who Have Sex with Men (MSM) in Beijing: An Open Cohort Study.
abstract: BACKGROUND
  This study investigated HIV and syphilis incidence among men who have sex with men (MSM) in Beijing, China.
  
  
  METHODS
  An open cohort was established from September 2009 to April 2012. Participants were followed up with every three to four months after recruitment and for thirty-one months in total. Chi-square tests were used to compare demographic and behavioral characteristics between participants who were followed up with and those lost to follow up. Univariate and multivariate Cox proportional hazards regression analyses were used to examine demographic and behavioral associations with HIV and syphilis incidence.
  
  
  RESULTS
  69.7% (699/1,003) of the participants finished at least two follow-up surveys during the study period. Variables which corresponded to increased loss to follow-up included younger age, less education, non-identification of homosexual identity, and migrant status. A total of 1,045 person-years (PYs) and 1,016.4 PYs were followed up for HIV and syphilis incidence estimation, respectively. The HIV incidence was 5.9 per 100 PYs and 7.8 per 100 PYs for syphilis. The predictors for the high HIV incidence included unsafe anal sex, sex after drinking alcohol and STI infection.
  
  
  CONCLUSIONS
  HIV incidence increased rapidly within the cohort, but syphilis incidence remained stable and decreased. More research is needed to provide multi-pronged HIV prevention interventions among MSM in order to reduce the increasing burden of HIV and sexually transmitted infections (STIs) in China.
authors.affiliation: Beijing Municipality Center for Disease Control and Prevention, Beijing, China.
authors.forename: Guowu
authors.initials: G
authors.lastname: Liu
authors.affiliation: Beijing Municipality Center for Disease Control and Prevention, Beijing, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Lu
authors.affiliation: Beijing Municipality Center for Disease Control and Prevention, Beijing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Beijing Municipality Center for Disease Control and Prevention, Beijing, China.
authors.forename: Dongyan
authors.initials: D
authors.lastname: Xia
authors.affiliation: Beijing Municipality Center for Disease Control and Prevention, Beijing, China.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Sun
authors.affiliation: National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Mi
authors.affiliation: Beijing Ditan Hospital, Capital Medical University, Beijing, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000068476:Beijing / Q000453:epidemiology; D015331:Cohort Studies; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013587:Syphilis / Q000453:epidemiology* / Q000517:prevention & control; D055815:Young Adult