HERACLIS‐HDV cohort for the factors of underdiagnosis and prevalence of hepatitis D virus infection in HBsAg‐positive patients.

Background and Aims: Hepatitis D virus (HDV) underdiagnosis remains common. We assessed the HDV screening and prevalence rates in HBsAg‐positive patients seen at tertiary liver centres throughout Greece as well as factors affecting HDV diagnosis. Methods: All adult HBsAg‐positive patients seen within the last 5 years were included. Non‐screened patients who visited or could be recalled to the clinics over a 6‐month period were prospectively tested for anti‐HDV. Results: Of 5079 HBsAg‐positive patients, 53% had anti‐HDV screening (41% before and 12% after study initiation). Pre‐study (8%–88%) and total screening rates (14%–100%) varied widely among centres. Screening rates were associated with older age, known risk group, elevated ALT, centre location and size and period of first visit. Anti‐HDV prevalence was 5.8% without significant difference in patients screened before (6.1%) or after study initiation (4.7%, p = 0.240). Anti‐HDV positivity was associated with younger age, parenteral drug use, born abroad, advanced liver disease and centre location. Overall, HDV RNA detectability rate was 71.6% being more frequent in anti‐HDV‐positive patients with elevated ALT, advanced liver disease and hepatitis B therapy. Conclusions: Anti‐HDV screening rates and recall capabilities vary widely among Greek liver clinics being higher in HBsAg‐positive patients of known risk group with active/advanced liver disease seen at smaller centres, while non‐medical factors are also important. Anti‐HDV prevalence varies throughout Greece being higher in patients born abroad with younger age, parenteral drug use and advanced liver disease. Viremia is more frequently but not exclusively detected in anti‐HDV‐positive patients with elevated ALT and advanced liver disease. [ABSTRACT FROM AUTHOR]