Evaluation of a synthetic peptide-based assay and a rapid blot recombinant test for detection of antibodies to HIV-1 and HIV-2

The objective of this study was to evaluate two new serologic assays for detecting HIV-form 1 and HIV-2 positive and negative sera. A total of 154 human sera from Egypt and African countries was tested using a synthetic peptide-based passive hemagglutination assay [PHA] and a rapid dot-blot recombinant test [Test-Pack], both of which are marketed as HIV-1/HIV-2 combination assays. The results indicated that the PHA identified all HIV-1 and HIV-2 positive sera, although some reacted only weakly. It produced one false positive reaction. The Test-Pack correctly detected all positive sera and three false negatives. All tests ran concurrently. Both identified HIV-2 positive antibodies and HIV-1 positive antibodies sera

Evaluation of a synthetic peptide-based assay and a rapid dot-blot recombinant test for detection of antibodies to HIV-1 and HIV-2

Our objective was to evaluate two new serologic assays for detecting HIV-1 and HIV-2 positive and negative sera. A total of 154 human sera from African countries were tested using a synthetic peptide-based passive hemagglutination assay [PHA] and a rapid dot-blot recombinant test [Test-Pack], both of which are marketed as HIV-l/HIV-2 combination assays. Results indicated that the PHA identified all HIV-1 and HIV-2 positive sera, although some were only weakly reactive. It produced one false positive reaction. The Test-Pack correctly detected all positive and negative sera, although several negative sera produced extremely weak reactions. Both tests detected two HIV-2 positive sera which were non-reactive by HIV-1 screening assays

Screening for HIV: can we afford the false negative rate

False negative results by screening assays for HIV represent an important and serious concern. We have assayed fourty-three western-blot confirmed positive sera from North and East Africa by five HIV-1 screening assays, four ELISAs [Virgo, Behring, Dupont, and Organon] and a particle agglutination test [Serodia]. Results indicated low sensitivities, ranging from .77 - .86. Concordance of positive results by all five screening assays was complete in only 51%. However, only a small portion of the African sera was responsible for the majority of inaccurate and discordant results.In addition, if western blot positivity had been defined by more stingent criteria [i.e. presence of p31 reactivity], sensitivities of the screening assays would have increased dramatically