Anti-HBc testing for blood donations in areas with intermediate hepatitis B endemicity.

Preventing hepatitis B virus and other transfusion-transmitted infectious diseases relies on stringent blood-donor qualifications and on serological screening for infectious disease markers among potential donors. Several studies have evaluated the reduced risk of transfusion-transmitted infections that comes from screening for hepatitis B core antibody (anti-HBc) in addition to testing for hepatitis B surface antigen (HBsAg), using the currently available serologic tests (1–7) or the newly developed molecular biology assays (8–10). However , most of these analyses were based on data from regions with low hepatitis B endemicity and/or from blood banks from developed countries , where repeat donors account for the majority of the blood supply. In South America, screening for hepatitis B surface antigen (HBsAg) is mandatory (11–13). Brazil, Venezuela, and Ecuador have also introduced anti-HBc testing in recent years (11, 14). Evaluating the usefulness of anti-HBc screening is critical, particularly for Brazil and other countries that have intermediate and high hepatitis B endemicity. Reasons for this include: 1) a residual risk of transfusion hepatitis B is still present, despite the progressive improvement in the quality of the blood supply; 2) anti-HBc is the most prevalent marker among donors; and 3) anti-HBc seropositiv-ity is the main cause of donor deferral (15, 16). Safe and affordable screening policies should be based on an analysis of the economic burden and possible blood supply shortages due to discarding anti-HBc-positive units. The epidemiologic context, donor characteristics, hepatitis B vaccine coverage, and availability and cost of serologic tests are key elements to be considered. In order to discuss the pros and cons of anti-HBc screening in Brazil, we present an analysis of results from hepatitis B virus (HBV) and hepatitis C virus (HCV) serology in blood banks in that country. First, a brief description of the history and interpretation of the screening tests adopted to prevent posttransfusion hepatitis is presented. Second, hepatitis B screening data for all the regions of Brazil are reported. This overall analysis of anti-HBc screening among Brazilian blood donors can indicate the appropriateness of deferring blood units and also provide insights for research priorities to guide evidence-based policies on blood screening.