Insights into blood donor screening for occult hepatitis B virus infection

Thesis

Occult hepatitis B virus (HBV) infection remains a risk to the blood supply. Prevention of transmission by transfusion requires a numerous set of tests, including surface antigen, anti-core antibodies and HBV DNA. Since anti-core testing was introduced in 2022 in England, the effectiveness of testing and potential alternatives required investigations. This thesis details the development of assays that uncover the existence of donors with HBV DNA viral loads below the limit of detection of commercially available assays; the potential utility (and insensitivity) of next-generation sequencing assays in blood donor screening; the need for a second screening assay to reduce false positivity in anti-core screening assays; and an international survey gained insight into the screening practices for occult HBV infection, effectiveness of screening in preventing transfusion-transmitted infections, and the lack of consensus regarding donor follow-up. These results highlight the complexity of the diagnosis and care of individuals with occult HBV infection, and conclude that while screening strategies are necessary, a more sensitive screening strategy to identify occult HBV infections would improve blood safety even further. Further research could identify alternative biomarkers that could predict the presence of infectious forms of occult HBV, as well as gather insights from donors with occult HBV infection into their diagnosis and follow-up.

Authors: Fu, MX

• DOI: 10.5287/ora-yqeprva0a
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: assay sensitivity and limit of detection; Occult hepatitis B virus (OBI); blood services policy; confirmatory testing algorithms; transfusion-transmitted infection (TTI); transfusion medicine; anti-HBc screening; blood safety; molecular diagnostics; false-positive reactivity; donor follow-up and management; diagnostic assay development; public health virology; HBV DNA low-level viraemia; next-generation sequencing (NGS); blood donor screening; serological assays
• Subjects: Hepatitis B; Molecular virology; Public health; Hepatology; Hepatitis B virus; Blood donors; Blood banks; Medical virology; Diagnostic virology; Hepatitis, Viral; Virology