Blood donor hepatitis B data: An under-recognized surveillance resource in Canada

Hepatitis B virus (HBV) infection surveillance is essential to gauge progress toward elimination, assess success identifying/treating cases, and evaluate prevention strategies. Canadian surveillance relies primarily on case detection. Data on undiagnosed HBV infection prevalence are limited. We explore the insight blood donors can bring to surveillance.

Drawing upon the authors' expertise, operational knowledge, and published literature, we identified key topics to evaluate blood donor data. We then synthesized the relevant data and publications to propose unique insight gained from blood donor data.

Annually there are over 100,000 first-time donors; all are tested for anti-HBc, HBsAg, and HBV NAT. The infection rate (HBsAg- and/or NAT-positive) is about 70/100,000 donors, several-fold lower than general population estimates, and has decreased over the past two decades, consistent with an impact of vaccination programs and similar to the general population. Also similar to the general population, HBV infections are more common in Asian, Arab, and Black donors. There are a range of genotypes, with A and D more common in donors than in referred patients. Vaccine-age-eligible donors have lower chronic and resolved hepatitis B prevalence than vaccine-age-ineligible donors.

Blood donors are an underutilized source of hepatitis B surveillance data that can lend unique insight into a low-risk population unlikely to be tested in clinical settings. Such data could supplement case detection surveillance. The impact of childhood vaccination programs is evident in adult blood donors. Blood donor residual specimens may be suitable for HBV vaccine-related serosurveillance.