SENSITIVITY AND SPECIFICITY OF STANDARD AND RAPID HIV-ANTIBODY TESTS EVALUATED BY SEROCONVERSION AND NON-SEROCONVERSION LOW-TITER PANELS

Background and objectives: The aim of this study is to compare the rel ative sensitivity and specificity of commercial HIV-antibody assays us ing seroconversion, non-seroconversion panels, and negative blood dono r samples. Materials and methods: We evaluated the sensitivity of five standard ELISA HIV-antibody assays: Vironostika HIV Uni-Form II, Abbo tt recombinant HIV-1/HIV-2 third-generation EIA, Biotest Anti-HIV-1/-2 recombinant, Recombigen HIV-1/HIV-2 EIA and Wellcozyme HIV 1+2 (VK54/ 55), and three rapid screening tests, Capillus HIV-1/HIV-2, Abbott Tes t Pack HIV-1/HIV-2 third-generation EIA, and Sensy-Test HIV 1/2. All t ests were assessed using four panels of plasma samples obtained from i ndividuals who were seroconverting and a low-titre HIV-antibody panel of samples. Specificity of the standard screening tests was determined on 3,500 HIV-antibody-negative blood donor samples. Results: There wa s no statistically significant difference in sensitivity between the f ive standard ELISA tests. One of these tests was significantly less sp ecific than the others. The standard ELISA tests detected all the low- titre HIV-antibody-positive samples. Two of the rapid screening tests were significantly less sensitive on the seroconversion panels and all three tests failed to detect at least one of the positive samples in the low-titre panel. Conclusions: The additional risk of using one or other of the standard ELISA tests under review of not detecting all HI V-positive units of blood is not statistically significant. Using some of the rapid screening tests will, however, add a significant additio nal risk. A rapid screening test should therefore be adopted only afte r careful consideration of the effect of a possible lack of sensitivit y on the safety of the blood supply.