HIV-1 and Syphilis Prevalence Among Local Chinese and Cross-border Migrant Female Sex Workers in Sino-Vietnam Border Cities in Guangxi, China: a Nine-year Consecutive Cross-sectional Study
Authors: Liang Bingyu , Zhang Fei , Wei Dongmei , Zhang Peidong , Wei Guangwu , Mo Shide , Nong Aidan , Ou Yanyun , Wu Zhenxian , Xie Hai , Liang Xu , Huang Jiegang , Jiang Junjun , Liu Jie , Liao Yanyan , Liu Deping , Liang Hao , Ye Li 
Published: October 2021

Abstract
Background To analyze the trends of HIV-1 and syphilis prevalence as well as associated factors among local Chinese female sex workers (LCFSWs) and cross-border migrant female sex workers (CMFSWs) in Sino-Vietnam border cities in Guangxi, China. Methods A consecutive cross-sectional study was conducted from 2010 to 2018 in three border cities in Guangxi. The survey was conducted through face-to-face interview with a structured questionnaire. HIV-1 and syphilis infections were tested simultaneously. Cochran-Armitage analysis was used to assess the trends of HIV-1, syphilis and HCV prevalence, as well as the trend of risk behaviors, HIV/AIDS knowledge and prevention services. Multivariate logistics regression analysis was used to identify factors associated with HIV-1 and syphilis infection.Results Totally, 19873 LCFSWs and 1723 CMFSWs were enrolled. The overall prevalence of HIV-1 and syphilis infection was 0.91% and 5.14%, respectively. The HIV-1 prevalence among CMFSWs was higher than that among LCFSWs, without a declined trend. However, a downward trend was observed among LCFSWs. Overall, the main associated factors of HIV-1 infection among CMFSWs shifted from age >35 years old, staying in current residence for >12 months, self-reporting sexually transmitted infections (STIs) in the last year during 2010-2015 to inconsistent condoms use in commercial sex in last month, not receiving peer education and self-reporting STIs in the last year during 2016-2018. The main correlated factors of syphilis infection among CMFSWs changed from history of illicit drug use, staying in current residence for more than 12 months, self-reporting of STIs and inconsistent condoms use in commercial sex in the past month during 2010-2015 to working in low-tier venues, self-reporting of STIs in the last year, and sexing with commercial male clients who used aphrodisiac drugs during 2016-2018. For LCFSWs, the relative strong associated factors of HIV-1 infection shifted from receiving less than 6 years of education, illicit drugs use, and self-reporting STIs in the last year during 2010-2015 to sexing with commercial male clients who use aphrodisiac drugs and self-reporting of STIs during 2016-2018, while the main factors of syphilis infection changed from self-reporting STIs in the last year, history of illicit drug use and receiving less than 9 years of education during 2010-2015 to self-reporting of STIs in the last year, sexing with commercial male clients who use aphrodisiac drugs, and history of illicit drugs use during 2016-2018.Conclusions The relatively higher prevalence of HIV-1 infection and frequent risk behaviours among CMFSWs in border cities in Guangxi, indicating that CMFSWs is the high-risk population for HIV-1 infection and transmission in the region, and is the key population of HIV/AIDS prevention and control. Meanwhile, the change of HIV infection-associated risk factors over time suggests that HIV intervention strategies need to be changed accordingly.