Residual Risk of HBV in African Blood Banks: Systematic Review and Meta-Analysis

Background: Blood transfusions carry the risk of transmitting blood-borne infections. A precise estimate of the transfusion risk of viral infection will help to determine the effect of new and current safety measures in sub-Saharan Africa. This study proposes to estimate the residual risk of HBV in blood banks in African countries and to compare them to other countries in the South.

Methods: The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. PubMed, Medline, Google Scholar and Zotero were accessed. The eligibility criteria were based on published studies that had blood donors as participants, looking at the residual risk of HBV in developing countries and the technique was based on the search for HBsAg or Hepatitis B Core Antibodies or Nucleic Acid (DNA) testing. The Cochrane tool was used to assess the risk of bias.

Results: Twelve articles comprising 71,207 allogeneic and hepatitis B surface antigen (HBsAg)-negative blood donations were included in the meta-analysis. A total of 4912 HBsAg negative African donation including (51.0%) new donors and (49.0%) from regular donors. 80.8% of them were male and the median age was 28 years. Of 1225 HBV strains (47% and 53.4% incident cases) were frequencies in sub-Saharan Africa and in other Southern countries respectively. Considering the twelve participating blood centres as a whole, the incidence rate of new infections was high (4905.1) in sub-Saharan Africa than (869.7) in other Southern countries per 100,000 person-years. In contrast, the estimated residual risk in sub-Saharan Africa (5913 in 1 million donations) was five times higher than estimated in other Southern countries (1048.4 in 1 million donations).

Conclusion: Blood donations with HBsAg undetectable by routine testing and low levels of HBV DNA are extremely common in sub-Saharan Africa, at a rate of 5913 per 1 million donations. Given that at least several of these samples could reflect contamination or a false negative result, elimination of infection by a test limited to HBsAg does not prevent transmission.