Prevalence, Trends and Correlates of HIV, Syphilis and HCV Infection Among Chinese Local and Cross-border Migrant Female Sex Workers in the Sino-Vietnam Border Area of Guangxi, 2016-2021.

Female sex workers (FSWs) are considered a high-risk group for sexually transmitted infections (STIs). However, limited data exist on the prevalence and trends of HIV, syphilis and HCV among FSWs in the Sino-Vietnam border area. To determine the prevalence, trends and correlates of STIs among Chinese local FSWs (CL-FSWs) and cross-border migrant FSWs (CM-FSWs), we conducted consecutive cross-sectional surveys from 2016 to 2021, recruiting 7747 CL-FSWs and 932 CM-FSWs. The overall HIV, syphilis and HCV prevalence declined from 1.0%, 8.8% and 1.7% to 0.1%, 0.9% and 0.3%, respectively. There was no significant downward trend in the overall HIV and syphilis prevalence. However, HCV prevalence showed a decreasing trend among CL-FSWs. CM-FSWs had higher HIV prevalence (2.5% vs. 0.6%). Similarities and differences in STIs-related factors existed between CM-FSWs and CL-FSWs. For instance, receiving HIV-related services in the last year reduced the risk of HIV infection (for CM-FSWs: aOR = 0.234, 95% CI: 0.055-0.993; for CL-FSWs: aOR = 0.182, 95% CI: 0.058-0.567). Serving male clients at least 50 years old increased the risk of syphilis infection (for CM-FSWs: aOR = 4.277, 95% CI: 1.535-11.917; for CL-FSWs: aOR = 1.404, 95% CI: 1.087-1.815). Moreover, CM-FSWs with past-year STIs history had a higher risk of HIV (aOR = 34.976, 95% CI: 5.338-229.176) and HCV infection (aOR = 17.649, 95% CI: 1.846-168.846), both of which were associated with multiple factors in CL-FSWs. It is therefore necessary to develop effective, accessible, high-quality and targeted interventions for CM-FSWs and CL-FSWs.