First report of anti-HDV antibodies in HBsAg-negative blood donors with detectable HBV-DNA in southern Mozambique

This study aimed to evaluate the seroprevalence of hepatitis D virus in hepatitis B virus positive blood donors in southern Mozambique. A cross-sectional study was conducted among blood donors in southern Mozambique between December 2022 and January 2024. HBV infection was defined by HBsAg positivity and/or detectable HBV DNA. HDV serology was assessed among HBV-positive samples. Samples that tested positive for anti-HDV were tested for anti-HBc and HDV RNA. Among 3,855 donors screened, 72 (1.9%) were HBsAg-positive, while 65 (2.5%) HBsAg-negative donors had detectable HBV DNA, suggesting occult HBV infection. No Anti-HDV was detected in HBsAg-positive samples (0; 95% CI: 0.0–5.0%). The seroprevalence of anti-HDV in HBsAg-negative samples with detectable HBV DNA was 1.5% (1; 95% CI: 0.04–8.4%). No HDV RNA was detected in the anti-HDV-reactive sample. In conclusion, only one anti-HDV-reactive sample was identified among HBsAg-positive blood donors, suggesting a low frequency of detectable HDV exposure in this study.