Hepatitis Delta Virus Testing and Prevalence Among Chronic Hepatitis B Patients Across Three U.S. Safety-Net Health Systems.

Background & aims: Despite a high prevalence of risk factors associated with hepatitis delta virus (HDV) infection among safety-net populations, data evaluating HDV testing and prevalence are limited. We aim to evaluate HDV testing practices and HDV prevalence among an ethnically diverse, multi-center cohort of safety-net patients with chronic hepatitis B (CHB).

Methods: We retrospectively evaluated 13,218 patients with CHB (54.2% male, 57.9% non-white minorities, 12.5% HIV, 23.0% HCV) across three U.S. safety-net health systems from 2010-2022 to evaluate proportion tested for HDV and proportion positive among those tested. Adjusted multivariate logistic regression models evaluated for predictors of HDV testing and predictors of anti-HDV positive.

Results: Anti-HDV testing was performed in 6.1% overall and in 4.9% that met AASLD criteria for HDV testing. Greater odds of testing was observed in men vs. women (OR 1.49, 95%CI 1.27-1.75), Asian individuals vs. white individuals (OR 2.18, 95%CI 1.74-2.72), black/African American individuals vs. white individuals (OR 1.29, 95%CI 1.07-1.56), and patients with Medicare or Medicaid. Among CHB patients tested for HDV, 15.7% were positive (22.9% among those meeting AASLD HDV testing criteria). Only 2 (1.6%) patients had follow-up HDV RNA testing. Greater proportion of anti-HDV positive was observed in patients with baseline cirrhosis (47.4% vs. 13.3%, p<0.001), and patients with Medicare or Medicaid vs. those with commercial insurance.

Conclusions: Among an ethnically diverse, multi-center safety-net cohort of CHB patients, low rates of HDV testing were observed, even among those with high-risk HDV risk factors. Among those tested, 15.7% were positive, only 2 had follow up RNA testing. This highlights the need for greater awareness, education, and advocacy to improve HDV testing rates.