Cross-sectional study finds rare anti-HDV reactivity among southern Mozambique blood donors

A cross-sectional study of blood donors in southern Mozambique detected anti-hepatitis D virus antibodies in one donor whose sample lacked hepatitis B surface antigen, or HBsAg, but contained detectable hepatitis B virus DNA. The study screened 3,855 donors between December 2022 and January 2024. Investigators found no anti-HDV antibodies in HBsAg-positive samples, while the single reactive result occurred among HBsAg-negative donors with detectable HBV DNA. No HDV RNA was detected in that reactive sample.

Among the 3,855 donors screened, 72, or 1.9%, were HBsAg-positive. Another 65 donors, corresponding to 2.5% of the HBsAg-negative group, had detectable HBV DNA. The authors described this HBsAg-negative, HBV-DNA-positive pattern as suggesting occult HBV infection. HDV serology was performed on samples from donors classified as HBV-positive through HBsAg positivity and/or detectable HBV DNA, allowing the researchers to assess anti-HDV reactivity in both groups.

No anti-HDV was detected in the HBsAg-positive samples, yielding an estimated seroprevalence of 0%, with a 95% confidence interval of 0.0% to 5.0%. Among the 65 HBsAg-negative donors with detectable HBV DNA, one sample was anti-HDV-reactive. This corresponded to anti-HDV seroprevalence of 1.5%, with a wide 95% confidence interval of 0.04% to 8.4%. The reactive sample was also tested for anti-HBc and HDV RNA. No HDV RNA was detected. Based on the study’s stated interpretation, the antibody result provided evidence of detectable HDV exposure, but the absence of HDV RNA in the single reactive sample did not demonstrate active HDV infection or ongoing viral replication at the time of sampling.

The findings are limited by the cross-sectional design, the small number of anti-HDV-reactive samples, and the focus on blood donors from one geographic area. The confidence interval of 0.04% to 8.4% reflects substantial uncertainty around the 1.5% estimate, while the negative HDV RNA result restricts conclusions about viral activity in the one positive donor. The study did not determine how HDV exposure occurred or establish transmission patterns, clinical outcomes, or the prevalence of HDV infection in the wider population. Its authors concluded that detectable HDV exposure was infrequent in the population studied. More broadly, the results show that anti-HDV reactivity was not confined to the HBsAg-positive group: it was identified in one donor with detectable HBV DNA but no HBsAg.

Subject of Research: Prevalence of anti-HDV antibodies among blood donors with HBsAg positivity or detectable HBV DNA in southern Mozambique

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

Article References: Matola, O., Remane, K., Mussá, T., & Mabunda, N. (2026). First report of anti-HDV antibodies in HBsAg-negative blood donors with detectable HBV-DNA in southern Mozambique. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14656-x

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14656-x

Keywords: hepatitis D virus, anti-HDV antibodies, occult hepatitis B, HBV DNA, HBsAg, HDV RNA, blood donors, Mozambique, seroprevalence, cross-sectional study, First, report