The Seroprevalence, Risk Factors, and Clinical Profile of Hepatitis D in Patients with Chronic Hepatitis B in Oman: A Multicenter Cross-Sectional Study

Background: Since the introduction of the hepatitis B virus (HBV) vaccination program in Oman in 1990, the HBV prevalence has markedly decreased. However, hepatitis D virus (HDV) infection, which is associated with progressive liver disease in patients with chronic HBV, remains understudied in the Omani population. This study aimed to estimate HDV’s seroprevalence, characterize its virological and clinical features, and identify factors associated with anti-HDV positivity among adults with an HBV infection in Oman. Methods: We conducted a multicenter cross-sectional study in 2024 at two referral hospitals and two polyclinics in Oman. Adult patients with chronic HBV (HBsAg-positive for > 6 months) were enrolled. Demographic, clinical, laboratory, imaging, and elastography data were collected. The total anti-HDV antibodies were tested using an ELISA; HDV RNA was tested for anti-HDV-positive or equivocal results. Fibrosis was assessed using transient elastography and clinical evaluation. Logistic regression identified predictors independently associated with anti-HDV positivity. Results: Among 639 patients (59.3% male; mean age of 46.6 ± 8.8 years), 36 patients were anti-HDV-positive, resulting in an HDV seroprevalence of 5.63% (95% CI: 4.10–7.70). Only one anti-HDV-positive patient had detectable HDV RNA, which became undetectable on follow-up without HDV treatment. The anti-HDV-positive patients were more frequently female and had a higher frequency of prior blood transfusions. In a multivariable analysis, blood transfusions were independently associated with anti-HDV positivity (OR of 36.72, 95% CI: 4.03–334.24; p =0.001), whereas male sex was associated with lower odds of being anti-HDV-positive (OR of 0.10, 95% CI: 0.04–0.28; p < 0.001). All the anti-HDV-positive patients had mild fibrosis (F0–F1). Conclusions: Our study demonstrated an anti-HDV prevalence of 5.63% among adults with chronic HBV infection in Oman, while active viremia appeared to be rare. Blood transfusions were the main identified risk factor. Given the very low HDV viremia and potential limitations of the assay used, targeted screening of higher-risk groups may be efficient, but universal one-time screening remains reasonable where feasible to avoid missed cases.