Three commercially available 3rd-generation anti-HCV ELISAs (Abbott, Murex and Ortho) were evaluated in various serum panels: (A) blood donor samples (n = 403) with 1st- or 2nd-generation anti-HCV ELISA (various manufacturers) positive test results; (B) non-A, non-B hepatitis patients (n = 212); (C) multi- transfused patients (n = 253); (D) serial dilutions of HCV confirmed (RIBA and PCR) positive blood donors (n = 24), and (E) first-time blood donors (n = 1,055). All samples of panels A, B and C were tested in PCR and RIBA-2. In panels A, B and C, 398 samples were HCV PCR positive: all were detected by Abbott and Ortho, and 397 (99.7%) by Murex. The sample missed by the Murex ELISA showed an isolated anti-C33c reactivity in RIBA-2. In panels A-C, 442 samples were RIBA-2 positive and all were detected by the 3 tests. With Probit analysis on results of panel D, no significant difference in sensitivity was observed between the 3 evaluated ELISAs. Specificities of Abbott, Murex and Ortho in 1,055 blood donors were 99.7, 99.3 and 99.9%, respectively (NS, χ2). We conclude that the sensitivity and specificity of the 3 ELISAs are comparable although the C33c antigen in the Murex VK47 test should be improved.

No abstract

Recently, an assay for detection of provirai HIV-1 DNA in leukocytes became commercially available. This assay (Amplicor HIV-1 test, Roche Diagnostic Systems) multiplies HIV-1 DNA up to a detectable level, using the polymerase chain reaction. We studied performance of this assay on 74 samples from HIV-1-infected patients and on 41 samples from healthy blood donors. Twice a negative control sample appeared to be erroneously reactive. However, sensitivity and specificity on the patient and donor samples both were 100%. To avoid false-positive results, we advise to repeat initially reactive samples if no other data confirm HIV-infection.

No abstract

No abstract