# Unexpectedly low prevalence of hepatitis delta virus infection in Southern Viet Nam

## TL;DR

This study found that hepatitis delta virus (HDV) is very rare in Southern Vietnam, suggesting it is not a major cause of liver disease in this region.

## Contribution

The study reveals unexpectedly low HDV prevalence in Southern Vietnam compared to other regions, highlighting the need for region-specific screening strategies.

## Key findings

- HDV antibodies were detected in only 1.5% of 721 HBsAg positive individuals in Southern Vietnam.
- HDV prevalence was not significantly different across groups with liver disease or chronic hepatitis B.
- The low HDV prevalence suggests it is not a major contributor to liver disease in Southern Vietnam.

## Abstract

Viet Nam faces a significant burden of viral hepatitis-associated liver disease, but the contribution of HDV, the most severe form of viral hepatitis, remains underinvestigated. HDV is substantial in the Northern and Central regions, but has not been documented in the South of Viet Nam. To investigate HDV prevalence and its association with severe liver disease in Southern Viet Nam, we used the standardized assay (LIAISON XL Anti-HDV) to detect HDV antibodies (anti-HDV) in 721 HBsAg positive individuals with hepatitis flare (n = 158), liver cirrhosis (LC) (181), hepatocellular carcinoma (HCC) (207), chronic hepatitis B (CHB) (175). Unexpectedly, anti-HDV was rare and only detected in 11/721 participants (1.5%), and not significantly different among groups: 2/158 (1.3%) in flare, 4/181 (2.2%) in LC, and 5/207 (2.4%) in HCC, and 0/175 (0%) in CHB. This suggests that HDV is not one of the major contributors to the high burden of liver disease in Southern Viet Nam. The discrepancy of HDV prevalence between Northern-Central and Southern regions suggests location-specific distribution of HDV, which in turn reflects differences in HDV transmission routes, study populations, and/or study methodologies. Our study underscores the need for tailored, regional screening strategies rather than a single national guideline for HDV infection.

The online version contains supplementary material available at 10.1038/s41598-025-33268-0.