Risk factors for hepatitis C virus infection in hepatitis C virus antibody ELISA-positive blood donors according to RIBA-2 status: A case-control survey



Studies of blood donors positive for antibody to hepatitis C virus on enzyme-linked immunosorbent assay are probably biased by the large number of false-positive results. We evaluated the epidemiological and biological characteristics of 177 such donors with regard to the confirmatory secondgeneration RIBA test (Ortho Diagnostic Systems) and have compared the results to those from an age- and sex-matched control group of 177 donors negative for antibody to hepatitis C virus on enzyme-linked immunosorbent assay. Second-generation recombinant immunoblot assay was positive in 38% of cases, indeterminate in 6% and negative in 56%. The case-control study showed a significantly higher frequency of intravenous drug abuse (27% vs. 0%), blood transfusion (22% vs. 9%), history of jaundice (21% vs. 7%), elevated ALT level (49% vs. 4%) and HBc antibody positivity (32% vs. 7%) in second-generation recombinant immunoblot assay–positive donors. No such differences were found between the second-generation recombinant immunoblot assay–negative donors and their controls. The 35 second-generation recombinant immunoblot assay–positive donors without histories of transfusion or intravenous drug abuse had a significantly higher frequency of surgery with major blood loss or prolonged stays in areas of hepatitis B virus endemicity than did their controls (20% vs. 0% and 49% vs. 26%, respectively). In conclusion, at least one risk factor for HCV infection was identified in 82% of the secondgeneration recombinant immunoblot assay–positive donors, 91% of whom could have been identified on the basis of these risk factors, ALT level and presence of HBc antibody. (HEPATOLOGY 1993;17:183–187.)