[Consecutive cross-sectional survey of prevalence of HIV infection/STD and related factors in Vietnamese female sex workers at a China-Vietnam border area, 2014-2015].

Objective: To investigate the prevalence of HIV infection/STD and related factors in Vietnamese female sex workers (FSWs). Methods: Consecutive cross-sectional surveys were conducted in June 2014, December 2014, May 2015 and November 2015 in Hekou, a county bordering Vietnam in Yunnan province. Convenience sampling were adopted to select 1 058 Vietnamese FSWs aged>16 years. Questionnaire interview were used to collect the information about their demographics, sexual behaviors and drug use. Serum and urine samples were collected for HIV infection/STD detection and drug use test. Trend χ(2) test was applied for HIV infection/STD and drug use trend analysis. Multivariate logistic regression model was used to identify the related factors. Results: The consecutive cross sectional surveys indicated that the prevalence of HIV infection in Vietnamese FSWs were 3.20%(7/219), 2.04%(5/245), 1.89%(5/265) and 1.82%(6/329) respectively; the HSV-2 positive rates were 57.08%(125/219), 58.37%(143/245), 38.11%(101/265) and 51.06% (168/329) respectively. In addition, the prevalence of syphilis were 0.91%, 1.51%, 0.75% and 1.22% respectively. HSV-2 infection prevalence showed a downward trend (χ(2)=4.823, P=0.028). By logistic regression analysis, the related factors for HIV infection in Vietnamese FSWs were being amphetamine type stimulants (ATS) positive (OR=10.18, 95%CI: 4.33-23.92) and being HSV-2 positive (OR=2.89, 95%CI: 1.09-7.88); Age (OR=1.88, 95%CI: 1.32-2.61), no-paid sexual partner (OR=1.59, 95%CI: 1.26-2.01) and being ATS positive (OR=2.48, 95%CI: 1.10-5.57) were related factors for HSV-2 infection. Conclusions: Compared with the results of previous studies, the HIV infection prevalence declined in Vietnamese FSWs, but the HSV-2 infection prevalence was still high. The association between ATS use and HIV infection/STD suggested the necessity of strengthening AIDS intervention in Vietnamese FSWs, including the control of new type drug and sexual transmission.