HEPATITIS-B CORE ANTIBODY SCREENING OF VOLUNTARY BLOOD-DONORS - AN EXTENDED PILOT-STUDY USING A MODIFIED PASSIVE HEMAGGLUTINATION ASSAY

Screening for hepatitis B surface antigen (HBsAg), even by the most se nsitive techniques, fails to detect all carriers of the hepatitis B vi rus (HBV). The presence of hepatitis B core antibody (anti-HBc) in the absence of HBsAg is a common finding in donors implicated in cases of post-transfusion hepatitis B (PTHB), and viral DNA may also be demons trated in many of these individuals. An extended pilot study of routin e screening of all donations for anti-HBc in addition to HBsAg was int roduced into the Mersey and North Wales Regional Transfusion Service i n November 1991 to improve surveillance for carriers of HBV. In order to reduce costs a modified passive have a sensitivity of 99% and speci ficity of 98% compared with a conventional assay. In the first 6 month s 60 530 donations were tested and 12 (0.02%) were found to have anti- HBc in the absence of HBsAg or adequate antibodies to HBsAg (anti-HBs) . These sera will later be submitted for polymerase chain reaction (PC R) testing in order to determine their infectivity or other-wise by th e detection HBV DNA sequences.