Cornelia Ottiger and Andreas R. Huber
Background: Most human immunodeficiency virus (HIV) point-of-care tests detect antibodies but not p24 antigen. Individuals with an acute or early primary HIV infection have generally high viral loads, but do not produce antibodies yet. The first 4th generation rapid test – Alere Determine HIV-1/2 Combo test, disappointedly, gave rarely positive p24-antigen results in acute or early infections. To improve the sensitivity, a new test was developed: Alere HIV Combo test.
Methods and Findings: A pilot study should elucidate the performance of the new Alere HIV Combo assay in comparison with Alere Determine HIV-1/2 Combo, and with the reference method. Samples of HIV-1 and HIV-2 infections of patients, who had not been under antiretroviral treatment before, were tested with both the new Alere HIV Combo and the Alere Determine HIV-1/2 Combo. Results were compared with Western blot and HIV viral loads from the reference laboratory. Fifteen samples were from patients with established HIV-1 infections, and two were of HIV-2; six samples were from acute or early primary HIV-1 infections. Fifteen samples were of negative HIV status. Alere Determine HIV-1/2 Combo gave correct results in established infections, where antibodies are produced, whereas in primary infections only HIV-1 of Clade B reacted weakly at the p24-antigen site. The new Alere HIV Combo assay reacted very well with all the positive samples of all clades, also in acute or early primary infections.
Conclusions: The new Alere HIV Combo rapid test performs well in detecting anti- HIV antibodies as well as p24-antigen.
