Prevalence of screening markers for HIV, hepatitis B virus, hepatitis C virus, and syphilis and associated factors among voluntary non-remunerated blood donors in Addis Ababa, Ethiopia: a cross-sectional study

Transfusion-transmissible infections (TTIs) remain a major blood-safety concern, particularly in low- and middle-income countries. This study estimated the prevalence of HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis screening markers and identified factors associated with TTI screening-marker positivity (positivity for at least one marker) among voluntary non-remunerated blood donors in Addis Ababa, Ethiopia. A cross-sectional study with prospective enrollment was conducted at the Ethiopian Blood and Tissue Bank Service from January to June 2026 among 2,642 blood donors. Sociodemographic, behavioural, clinical, and occupational data were collected using a structured questionnaire. The primary outcome was TTI screening-marker positivity; marker-specific prevalence was also estimated. Screening used chemiluminescent microparticle immunoassay, with transcription-mediated amplification nucleic acid testing for HIV, HBV, and HCV. Crude and adjusted odds ratios (CORs and AORs) with 95% confidence intervals (CIs) were estimated using logistic regression with team-clustered robust standard errors and, because only five teams were included, a wild cluster bootstrap sensitivity analysis. Ninety-six donors (3.63%; 95% CI: 2.95–4.41) had TTI screening-marker positivity. Marker-specific prevalence was 1.29% (95% CI: 0.92–1.80) for syphilis, 1.21% (95% CI: 0.86–1.71) for HBV, 0.95% (95% CI: 0.64–1.40) for HCV, and 0.57% (95% CI: 0.34–0.94) for HIV; 10 donors (0.38%; 95% CI: 0.20–0.70) had pairwise coinfections. Higher odds were associated with diploma-level education (AOR = 3.20, 95% CI: 1.63–6.29), multiple sexual partners (AOR = 23.41, 95% CI: 11.45–47.89; wild cluster bootstrap P = 0.120), and needlestick injury (AOR = 3.60, 95% CI: 1.66–7.80); lower odds with repeat donation (AOR = 0.30, 95% CI: 0.18–0.49) and static-site donation (AOR = 0.28, 95% CI: 0.13–0.58). Middle income showed an imprecise inverse association (AOR = 0.32, 95% CI: 0.11–1.00; P = 0.050). Overall TTI screening-marker positivity (3.63%) was moderate and lower than most previous Ethiopian estimates, with low marker-specific prevalence, but remains a blood-safety concern among voluntary non-remunerated donors in Addis Ababa. Estimates for multiple sexual partners were imprecise. Strengthening repeat-donor retention, pre-donation behavioural risk assessment, prevention of occupational blood exposure, and sensitive screening may improve transfusion safety.