Validation study of a conventional enzyme immunoassay to detect HIV antibodies in oral fluid

Abstract

The aim of our study was to validate the Genscreen HIV ½ version 2 (BIO-RAD) for detecting HIV antibodies in oral fluid specimens (OF). The advantage of assays to detect HIV infection in OF lies in the on-site easy access and noninvasive sample collection. Paired serum and OF were collected from 496 subjects (263 HIV-positive and 233 HIV-negative) using the Oracol test kit (Oracle Diagnostics, Inc). The quality of OF was verified by measuring total IgGs using the Human IgG ELISA Quantitation Kit (Bethyl Lab.inc). All reactive OF samples were retested by Western blot HIV1/2 BLOT 2.2 (MP Biomedical, Singapore, China). Of 263 OF samples from participants with blood-based HIV-positive results, 259 were positive by Genscreen HIV ½ version 2 (98.48% sensitivity, 95% CI; 96.2-99.6). The 233 individuals who had a non-reactive HIV blood test were found negative on testing their OF by Genscreen HIV ½ version 2 (100% specificity, 95% CI; 98.4-100). NPV and PPV of the assay were 98.31% (95% CI; 95.74-99.34) and 100%, (95% CI; 98.53-100.00), respectively. Genscreen HIV ½ version 2 (Bio-Rad) is aprospective method for HIV surveillance studies in hard-to-reach populations with high risk behavior using non-invasive OF collection (Tab. 1, Fig. 1, Ref. 16).