Multi-centre evaluation of the Determine HIV Combo assay when used for point of care testing in a high risk clinic-based population

• Published in: PloS one Vol. 9; no. 4; p. e94062
• Main Authors: Conway, Damian P, Holt, Martin, McNulty, Anna, Couldwell, Deborah L, Smith, Don E, Davies, Stephen C, Cunningham, Philip, Keen, Phillip, Guy, Rebecca
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.04.2014; Public Library of Science (PLoS)
• Subjects: Adult; Ambulatory Care Facilities; Analysis; Antigens; Biology and Life Sciences; Bisexual; Bisexuality; Care and treatment; Clinics; Comparative analysis; Diagnosis; Evaluation; Health aspects; Health risks; Health services; HIV; HIV antibodies; HIV Antibodies - immunology; HIV infection; HIV Infections - diagnosis; HIV Infections - immunology; HIV Seropositivity - diagnosis; HIV Seropositivity - immunology; Hospitals; Human immunodeficiency virus; Humans; Immunoassay; Infections; Infectious diseases; Laboratories; Male; Mass Screening; Medical diagnosis; Medical tests; Medicine and health sciences; Mens health; p24 Protein; Patients; Public health; Reagent Kits, Diagnostic - standards; Research and Analysis Methods; Ribonucleic acid; Risk factors; RNA; Sensitivity; Sensitivity and Specificity; Serology; Sexually transmitted diseases; Studies; Virology; Australia
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0094062

Determine HIV Combo (DHC) is the first point of care assay designed to increase sensitivity in early infection by detecting both HIV antibody and antigen. We conducted a large multi-centre evaluation of DHC performance in Sydney sexual health clinics. We compared DHC performance (overall, by test component and in early infection) with conventional laboratory HIV serology (fourth generation screening immunoassay, supplementary HIV antibody, p24 antigen and Western blot tests) when testing gay and bisexual men attending four clinic sites. Early infection was defined as either acute or recent HIV infection acquired within the last six months. Of 3,190 evaluation specimens, 39 were confirmed as HIV-positive (12 with early infection) and 3,133 were HIV-negative by reference testing. DHC sensitivity was 87.2% overall and 94.4% and 0% for the antibody and antigen components, respectively. Sensitivity in early infection was 66.7% (all DHC antibody reactive) and the DHC antigen component detected none of nine HIV p24 antigen positive specimens. Median HIV RNA was higher in false negative than true positive cases (238,025 vs. 37,591 copies/ml; p = 0.022). Specificity overall was 99.4% with the antigen component contributing to 33% of false positives. The DHC antibody component detected two thirds of those with early infection, while the DHC antigen component did not enhance performance during point of care HIV testing in a high risk clinic-based population.