Efficacy of screening donors for antibodies to the hepatitis C virus to prevent transfusion-associated hepatitis: Final report of a prospective trial

Abstract

Routine screening of blood donors for anti‐hepatitis C virus (HCV) has been implemented in most developed countries. However, the independent efficacy of such screening has not been established in a controlled, prospective study. We tracked 478 patients transfused with anti‐HCV‐negative blood by first‐generation enzyme‐linked immunoassay (EIA) between July 1989 and May 1990 and compared the incidence of transfusion‐associated hepatitis and HCV infections with that found among 280 patients transfused with blood unscreened for anti‐HCV during the immediately preceding year. Of the 280 patients who had received transfusions before donors were screened for anti‐HCV, 27 (9.6%) developed posttransfusion hepatitis and 1 additional patient sero‐converted to anti‐HCV without evidence of hepatitis, for a risk of posttransfusion HCV infection of 10.7% (28 of 262 recipients seronegative for anti‐HCV before transfusion). Of the 478 patients transfused after July 1989 with blood screened for anti‐HCV, only 9 (1.9%) developed posttransfusion hepatitis for a risk reduction of 80%. Seven of the 9 residual cases of hepatitis were caused by HCV (7 of 456 recipients seronegative before transfusion or 1.5%) for a risk reduction of transfusion‐associated HCV infection of 86%. In retrospect, an anti‐HCV positive donor was detected by second‐generation immunoassay in 4 (57%) of the 7 HCV cases from the study cohort and in 19 of the 23 (83%) cases from whom all donor samples were available for testing in the historical cohort. No additional infectious donors were detected by third‐generation immunoassay or serum HCV‐RNA by polymerase chain reaction. Implementation of donor screening for anti‐HCV with a first‐generation immunoassay appeared to be independently associated with an 80% and 86% reduction in the risks of transfusion‐associated hepatitis and HCV infection, respectively. Screening of donors with second‐generation immunoassays might have further reduced the risk by 57%. An additional 0.4% may be at risk of developing non‐A, non‐B, non‐C hepatitis. (Hepatology 1995;22:439–445.)