title: [A prospective cohort study on human immunodeficiency virus and syphilis seroconversion among injecting drug users].
abstract: OBJECTIVE
  To study the rate of human immunodeficiency virus (HIV) seroconversion, HIV transmission and related risk factors among injecting drug users (IDUs) in an area of Sichuan province.
  
  
  METHODS
  In November 2002, a community-based baseline survey was conducted to recruit 333 HIV-seronegative IDUs for a prospective cohort study in Xichang county of Sichuan province, China. Follow-up visits were carried out every 6 months to study the situation of drug use, sexual behaviors of the IDUs and blood specimens were collected to test for antibodies against HIV and syphilis.
  
  
  RESULTS
  During a 24-month follow-up period, cohort retention rate and HIV incidence were 75.7% and 2.53 per 100 person-years [95% confidence interval (CI): 1.10-3.97)], respectively. Multivariate Poisson regression model showed that risk factors which were significantly associated with HIV seroconversion would include: ethnicity (RR = 12.42; 95% CI: 2.72-56.74, P = 0.0012) and needle or syringe sharing in the past 3 months (RR = 4.06; 95% CI: 1.29-12.81, P = 0.0168). Syphilis seroconversion in this cohort was 4.71 per 100 person-years (95% CI: 2.59-6.82). In multivariate Poisson regression being female (RR = 4.42; 95% CI: 1.78-10.99, P = 0.0014) appeared to be the only factor which was significantly associated with syphilis seroconversion.
  
  
  CONCLUSIONS
  Our study results showed that there was a rapid transmission of HIV and syphilis among IDUs in Sichuan province, suggesting that effective intervention should be urgently taken.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Center for Sexually Transmitted Disease and Acquired Immune Deficiency Syndrome Prevention and Control, Chinese Center for Disease Prevention and Control, Beijing 100050, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Yin
authors.forename: Guang-ming
authors.initials: GM
authors.lastname: Qin
authors.forename: Yu-hua
authors.initials: YH
authors.lastname: Ruan
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Qin-ning
authors.initials: QN
authors.lastname: Hao
authors.forename: Xian-huang
authors.initials: XH
authors.lastname: Chen
authors.forename: Zheng-qing
authors.initials: ZQ
authors.lastname: Jiang
authors.forename: Ben-li
authors.initials: BL
authors.lastname: Song
authors.forename: Shi-zhu
authors.initials: SZ
authors.lastname: Liu
authors.forename: Xiao-yun
authors.initials: XY
authors.lastname: Cao
authors.forename: Chun
authors.initials: C
authors.lastname: Hao
authors.forename: Kang-lin
authors.initials: KL
authors.lastname: Chen
authors.forename: Yi-ming
authors.initials: YM
authors.lastname: Shao
mesh_terms: D015331:Cohort Studies; D006679:HIV Seropositivity / Q000276:immunology* / Q000635:transmission; D006801:Humans; D011446:Prospective Studies; D012307:Risk Factors; D012725:Sexual Behavior; D015819:Substance Abuse, Intravenous; D013587:Syphilis / Q000276:immunology* / Q000635:transmission