Detection of antibodies to hepatitis C virus in blood donors and their relationship to surrogate markers.

Stored serum samples from 7,179 nonselected blood donors were tested for anti-HCV using Ortho EIA first generation. Results were compared to data acquired by anti-HBc testing and ALT levels found in routine testing. 24 donors (0.33%) were repeatedly reactive with Ortho HCV EIA, 230 (3.20%) were anti-HBc-positive and 138 (1.92%) had raised ALT levels > or = 36 IU/l. A low correlation was found between HCV antibody screening with EIA and surrogate testing. When tested in addition with the Abbott HCV EIA, 20 of the 24 Ortho EIA-positive subjects showed a positive reaction. In the Abbott neutralization test 13 of these 20 (65%) were reactive. 8 (33.33%) of the 24 Ortho-EIA-positive donors were positive in the two-antigen-RIBA (first generation), 8 were indeterminate and 8 were nonreactive. The neutralization test and the RIBA can be used as supplementary tests fo further analyze HCV-EIA-positive specimens.