A US-Based Multi-Site Pilot to Screen Hepatitis B Surface Antigen-Positive Patients for Hepatitis D.

Hepatitis D (HDV) is a severe infection with well-recognised clinical ramifications that remains relatively neglected and underdiagnosed; consequently, the epidemiology of HDV is poorly characterised, both in the United States and globally. In 2022, a pilot project involving eight healthcare institutions was undertaken to ascertain the prevalence of HDV in healthcare institutions with an HBV seropositivity of at least 1%, describe the characteristics of patients testing positive for HDV, and evaluate diagnostic and laboratory processes of HDV screening. From August 2022 to April 2024, a total of 106,693 patients were tested for HBsAg, of whom 65,341 (61.2%) were female and 40,863 (38.3%) were male, with a mean age of 47 years. The overall HBsAg positivity rate was 1.04% (n = 1112). Among the HBsAg+ samples, 645 (58.0%) underwent HDV Ab testing. The HDV Ab positivity rate was 0.81% (n = 9), with 2 cases of HDV RNA positivity (0.18%). The incomplete testing reflects several challenges associated with screening for both HBV and HDV. Further research is necessary to better understand the epidemiology and burden of HDV in the United States and considerations for implementation.