Rapid and simple hepatitis assays: encouraging results from a blood donor population in Zimbabwe.

A rapid assay to detect antibodies to hepatitis C virus (HCV) in serum and two rapid/simple assays to detect hepatitis B surface antigen (HBsAg) in whole blood/serum were evaluated for their accuracy and suitability at the National Blood Transfusion Service, Harare, Zimbabwe. For this purpose, a total of 206 sera (196 routinely collected and 10 frozen) were tested using the HCV-SPOT (Genelabs Diagnostics), the SimpliRED HBsAg test (AGEN), and the Dipstick-HBsAg (PATH/Immuno-Chemical Laboratories). The results were compared with those obtained using a routine HBsAg enzyme immunoassay (EIA) (Auszyme, Abbott) and an HCV IgG second-generation EIA (Abbott). An HCV IgM test (Abbott) was used for samples that produced discordant results, and all HCV-reactive samples were confirmed using the INNO-LIA HCV Ab III synthetic peptide assay (Innogenetics). Overall, the concordance between the HCV-SPOT and the HCV EIA was 97.6% (201/206). For the 193 sera that were true HCV negatives, the number of false positives was six with the HCV-SPOT test, while the HCV EIA produced three (specificity = 97.0% and 98.5%, resp.). Of these false positives, two were so in both tests. None of the false positives contained IgM antibodies to HCV, and there were no false negatives in the two HCV tests. The concordance between the two rapid HBsAg tests and the HBsAg EIA was 99.5% (205/206). All the rapid/simple tests were easy to perform and interpret, required no (or minimal) laboratory equipment, and could be taught easily to local laboratory personnel. The cost of these tests is equivalent to or less than that of routine EIA methods.