Burden of hepatitis B virus and syphilis co-infections and its impact on HIV treatment outcome in Ethiopia: nationwide community-based study

BACKGROUND: Hepatitis B virus (HBV) and syphilis have been the most common co-infections that hinder treatment outcomes and increase early mortality among people living with human immunodeficiency virus (PLHIV). In this study, we aimed to determine the burden of HBV and syphilis co-infections and its impact on treatment outcomes among PLHIV in Ethiopia. METHODS: We used data from the Ethiopian Population-based HIV Impact Assessment (EPHIA), which was a household-based national survey in 2017/2018. Human immunodeficiency virus (HIV) testing was done among 19,136 participants using the national testing algorithm and 662 participants (3.50%) were HIV positives who were further tested for viral hepatitis and syphilis co-infections using HBV surface antigen and Chembio DPP syphilis assay, respectively. Viral load, CD4 count and high-sensitivity C-reactive protein (hsCRP) were done to measure HIV treatment outcomes. Descriptive statistics were used to determine the burden of co-infections and a logistic regression model to evaluate the determinants of co-infections using STATA V17.0. RESULTS: Overall prevalence of HBV and syphilis co-infection was 5.5% and 2.2%, respectively. HBV and syphilis (double co-infection) was 5.9%. The highest prevalence of HBV co-infection was observed among 10–19 years age group (12.9%) and male participants (7.44%) while the highest syphilis co-infection was among people aged ≥50 years (3.5%) followed by age groups 40–49 (3.3%) and 10–19 years (3.2%). Syphilis co-infection was higher among males (5.2%) compared to females (1.1%). After adjusted regression analysis, HBV co-infected PLHIV had higher odds of virologic failure (AOR (95% confidence interval (CI)) = 6.3 (4.2–14.3)), immunosuppression (CD4 count < 500 cells/mm(3)) (AOR (95%CI) = 2.1(1.3–4.9)) and inflammation (hsCRP >10 mg/dL) (AOR (95%CI) = 9.2(4.3–14.6)). Immunosuppression was also significantly higher among syphilis co-infected PLHIV (AOR (95%CI) = 3.4 (1.3–5.2)). CONCLUSIONS: Burden of HBV and syphilis co-infections is high particularly among male and adolescent PLHIV and these co-infections hinder virologic and immunologic outcome in Ethiopia. Hence, the program shall enhance HBV and syphilis testing and treatment.