HIV incidence and associated risk factors among female sex workers in a high HIV-prevalence area of China.

BACKGROUND: Heterosexual sex is replacing injection drug use as the main mode of HIV transmission in China. The objective of this study is to determine HIV incidence and associated risk factors among female sex workers (FSWs) in China. METHODS: From March 2006 to November 2009 FSWs in Kaiyuan City Yunnan were recruited into an open cohort study. Participants were interviewed and tested for HIV and sexually transmitted infections every 6 months. A multivariate Cox proportional hazards regression model with time-dependent variables was used to measure associations between independent variables and HIV seroconversion. RESULTS: During 3.5 years of follow-up 19 incident cases of HIV infection were diagnosed yielding an overall incidence of 1.44 per 100 person-years (95% confidence interval [CI]: 0.87-2.24). In the multivariate Cox proportional hazards regression model noninjection drug use (adjusted hazard ratio [AHR]: 6.7 95% CI: 2.25-19.93) inconsistent condom use with clients in the previous week (AHR: 2.9 95% CI: 1.03-8.34) and number of clients in the previous week >/=7 (AHR: 4.9 95% CI: 1.81-13.13) were all independent risk factors for HIV seroconversion. CONCLUSION: These results underscore the urgency for preventive interventions on sexual and drug use behaviors among FSWs including condom promotion as well as sexually transmitted infection screening and treatment.