Hepatitis C virus antibodies and hepatitis C virus RNA in Chinese blood donors determined by ELISA, recombinant immunoblot assay and polymerase chain reaction

Antibodies to hepatitis C virus (anti-HCV) were determined in Chinese blood donors from the city of Wuhan by a second generation ELISA screening test and a confirmatory recombinant immunoblot assay (RIBA II). Two materials of 281 and 222 sera were sampled under similar conditions in 1989 and 1990, respectively. The first collection of sera was sent to Sweden in lyophilized form, the second directly as fresh unfrozen sera. A high proportion (7.1%) of the lyophilized sera reacted positively in the anti-HCV screening assay, but only seven (2.5%) were positive by the RIBA confirmatory test. In four of these sera HCV-RNA could be detected by polymerase chain reaction (PCR) analysis. In the second material of fresh sera six reacted positively in the screening anti-HCV ELISA, but only one was RIBA positive and four were RIBA indeterminate. None of these sera was positive for HCV-RNA. Thus, the overall prevalence of anti-HCV among the 503 Chinese blood donors, as identified by RIBA, was 1.6%, and of HCV-RNA by PCR 0.8%. The confirmed antibody prevalence is higher than reported from the Western world. Caution about using data from the screening ELISA only, especially if sera have been handled in an unorthodox way, is emphasized.