Detection of antibody to hepatitis C virus by second-generation enzyme immunoassay

Of 106 samples positive for antibody to hepatitis C virus (anti-HCV) by first-generation enzyme immunoassay (EIA-1), 63 (59%), 67 (63%) and 43 (41%) were reactive by second-generation EIAs (EIA-2). Among positive EIA-1 samples, 33% were reactive by second-generation recombinant immunoblot assay (RIBA-2). A higher percentage of positive EIA-2 samples, however, were reactive by RIBA-2. In the high-risk group there was a correlation between the EIA-2 and RIBA-2 results. In the low-risk group, however, the correlation was poor except in blood donors, in whom 57% of samples were reactive by EIA-2 and RIBA-2. Results showed that the sensitivity and specificity of EIA-2s has improved although further improvement is desirable.