In a resource-constrained African setting, children suspected of being infected with HIV are often screened with rapid antibody tests prior to definitive diagnosis with viral genome detection. It has previously been shown that a rapid antibody assay such as the Capillus HIV-1/HIV-2 test may have a high false-negative rate in infants. In this study CD(4) (+) count and percentage, HIV-1 viral load, antigen-specific reactivity, and age was explored as predictors of negative or low antibody reactivity by this assay. Young age was found to be the only factor associated significantly with low antibody reactivity. This phenomenon appeared to be specific to HIV since no such age association was found for antibody reactivity to tetanus toxoid. Rapid assays only validated in adults should therefore be used with utmost caution in young infants since this may lead to high rates of false-negative results.
(c) 2010 Wiley-Liss, Inc.