[Initial experiences with HCV detection and confirmation tests of the 3rd generation].

We compared the reactivity of a new 3rd-generation anti-HCV enzyme immunoassay (EIA) using an additional, nonstructural antigen from the NS5 region, with a currently used 2nd-generation anti-HCV EIA, by investigating 419 serum specimens from healthy blood donors with normal liver function and 256 samples from patients at risk for hepatitis C infection; 2 of 419 blood donors and 1 of 256 patients were reactive to the NS5 region antigens only (later confirmed by Western blot and RP-2 RIBA), whereas 1 patient was reactive with the 2nd-generation EIA only (antibodies against c33c). We further evaluated the recently developed anti-HCV RP-2 RIBA by testing samples, that were indeterminate by the 2nd-generation RIBA. Nine of 15 patients were identified as reactive by RP-2 RIBA, 6 remained indeterminate. Of the 6 blood donor samples tested, 2 were found reactive, 1 remained indeterminate, and 3 were negative. These test results suggest a higher sensitivity and specificity of the RP-2 RIBA, whereas the relevance of an isolated NS5 EIA reactivity remains to be established.