POSTTRANSFUSION HEPATITIS - IMPACT OF NON-A, NON-B-HEPATITIS SURROGATE TESTS

Canada has not introduced the non-A, non-B (NANB) surrogate marker tes ts (antibodies to hepatitis B core antigen and alanine aminotransferas e) to screen donated blood. We evaluated the effect of NANB surrogate markers in reducing post-transfusion hepatitis in a prospective random ised intervention study. From 1988 to 1992, 4588 subjects were enrolle d into two study groups that received allogeneic blood from which unit s positive for NANB surrogate markers were either withheld (n=2311) or not withheld (n=2277). We also assessed a simultaneous non-randomised cohort (n=650) of subjects who received only syngeneic blood. All sub jects were followed up for 6 months and assessed for the presence of p ost-transfusion hepatitis due to hepatitis A, B, C, non ABC, Epstein-B arr virus (EBV) and cytomegalovirus (CMV). Withholding of blood contai ning NANB surrogate positive units reduced the overall posttransfusion hepatitis rate by 40% (p=0.065) and the hepatitis C rate by 70% (p=0. 05). Most of the benefit of NANB surrogate testing was due to reduced frequency of hepatitis C virus after transfusion before all donor bloo d was screened far anti-HCV. During this time the overall post-transfu sion hepatitis rate per 1000 transfusion recipients was 20.2 in the no -withhold group compared with 5.0 in the withhold group (p=0.05), and the HCV hepatitis rate was 12.6 and 0 respectively (p=0.06). After the introduction of HCV screening, the overall posttransfusion hepatitis rates were 8.6 and 6.8 per 1000 (p=0.55) respectively. Our study indic ates that screening of blood donors with the NANB surrogate markers wa s of value in reducing HCV infection before HCV screening began, but s ubsequently the value of screening cannot be clearly established.