Magnitude and Determinants of Syphilis and HIV Co-Infection Among Female Sex Workers in Ethiopia: Evidence from Respondent Driven Samples, 2019–2020

BACKGROUND: Female sex workers (FSWs) play an important role in transmitting Human Immunodeficiency Virus (HIV) and syphilis from high-risk groups to the general population. Syphilis and HIV infections are generally more prevalent among FSWs. However, in Ethiopia, up-to-date evidence about Syphilis–HIV co-infections among FSWs was lacking. OBJECTIVE: To determine the magnitude and determinants of Syphilis–HIV co-infection among FSWs in Ethiopia, 2019–2020. METHODS: A cross-sectional HIV and other sexually transmitted infections Bio-Behavioral Survey (HSBS) was conducted using respondent-driven sampling (RDS) among 6,085 FSWs in Ethiopia from August 2019 to January 2020. Data was collected, merged with laboratory data, and analyzed in R software using the RDS package. The odds ratio was calculated at 95% CI to measure associations between the dependent and independent variables. Variables that yield p<0.25 in univariate analysis were included in multivariate analysis. In multivariate analysis, variables with p<0.05 were declared as statistically significant. Results were presented in frequency tables and charts. RESULTS: The prevalence of Syphilis–HIV co-infection among FSWs was 2.9% [95% CI=2.6–3.2]. Age of the FSWs (15–19 years old (AOR=0.03; 95% CI=0.01–0.12)), non-formal educational level (AOR=3.18; 95% CI=1.78–5.68), monthly income <2,500 ETB (AOR=3.05; 95% CI=1.45–6.42), major depression (AOR=1.85; 95% CI=1.18–2.89), forced first sex experience (AOR=1.71; 95% CI=1.2–2.44), condom breakage (AOR=1.62; 95% CI=1.14–2.30), Hepatitis B seropositivity (AOR=2.32; 95% CI=1.10–4.90), and Hepatitis C seropositivity (AOR=5.37; 95% CI=1.70–16.93) were strongly associated with Syphilis–HIV co-infection among FSWs in Ethiopia. CONCLUSION: The prevalence of Syphilis–HIV co-infection among FSWs in Ethiopia was high. To ward off Syphilis–HIV co-infection among FSWs, a special FSWs-targeted HIV and Syphilis/STIs prevention program and treatment approach needs to be devised. An outreach approach to address the sexual and reproductive health needs of FSWs has to be part of the strategy.