Prospective Cohort Study To The Incidence Of HIV/STIs Among FSWs In Kaiyuan City

Background Female sex workers(FSWs) are one of the HIV/AIDS-related high risk populations in China;however,there is still lack of information about HIV/STIs incidence,HIV/STIs prevalence trends,and the changes in high-risk behaviors among FSWs.Objective(1) to estimate HIV prevalence trends and the correlates of HIV infection among China FSWs;(2) to estimate the longitudinal change in HIV/AIDS related high-risk behaviors among FSWs;(3) to measure HIV incidence and the characteristics of recently HIV-infected FSWs;(4) to evaluate the effect of HIV-1-specific IgG capture ELISA(BED-CEIA) on HIV incidence estimation among China FSWs by cohort survey.Method(1) Three-stage serial cross-sectional surveys were carried out among FSWs in Kaiyuan City,China between March 2006 and April 2007;(2) FSW participants who repeatedly attended serial cross-sectional surveys comprised an open-cohort.(3) FSWs participants who attended all the three cross-sectional surveys composed an close-cohort.(4) The effect of BED-CEIA estimated HIV incidence was evaluated by open-cohort survey among the same FSWs population.Result(1) The prevalence of HIV were 10.3%(76/737),11.9%(89/747) and 13.0%(92/705) among Kaiyuan FSWs who attended the serial cross-sectional surveys, but its increasing trend was not statistically significant(p＞0.1).Injection drug use history was the main risk factor among FSWs(adjusted OR=9.8);(2) The self reported illicit drug-using behaviors and high risk sexual behaviors among close-cohort of FSWs who attended all the three cross-sectional surveys decreased accompanied with the survey time.The decrease of STIs prevalence and urine positive rate among them confirmed their decreased high risk behaviors;(3)The incidence of HIV was 1.4(95%CI 0.5～3.3)/100 Person Year(PY) in the open-cohort.FSWs who were recently HIV-infected had obvious high risk sexual behaviors with clients and 4/5 of them were not illicit-drug using FSWs;(4) 42.1%(16/38) of BED-CEIA positive specimens were false positives(＞155 days),but after eliminating the misclassified long-term HIV infected specimens,the BED-CEIA estimated HIV incidence were similar with that of the cohort survey among the same FSWs(2.1/100PY vs.2.0/100PY;0.4/100PY vs. 0.6/100PY).Conclusion The main transmission route for HIV among Kaiyuan FSWs is changing from drug injecting behaviors to unprotected heterosexual behaviors. Strengthened efforts should be made to curb their unprotected commercial sex;the decrease in various high risk behaviors among Kaiyuan FSWs may be related to the HIV/STIs post-counseling and information provided by our questionnaire.With careful collection of information on previous HIV testing conditions and so on,BED-CEIA is appropriate for the estimation of HIV incidence among China FSWs.