Diagnostic value of two HIV rapid diagnostic tests 16 years after their adoption in national strategies in the Central African Republic (CAR)

The broad genetic diversity of HIV requires regular reassessment of adopted HIV diagnostic tests. The objective of this study was to reassess the performances of Determine® HIV 1/2 and Uni-gold® HIV1/2, 2 HIV rapid diagnostic tests of the national algorithm, adopted since 2005 in Central African Republic. A reference prospective panel of 150 plasma samples were tested in duplicate with Determine® HIV 1/2 and Uni-gold® HIV, according to reference serological immune-enzymatic method. Analytical and virological characteristics were calculated. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) of Determine® HIV 1/2 were 100%, as well as the specificity and NPV of Uni-gold® HIV 1/2. Uni-gold® HIV 1/2 sensitivity and PPV were 96 and 92%, respectively. The Cohen k coefficient was close to 1 for the 2 tests, 1 for Determine® HIV 1/2 and 0.97 for Uni-gold® HIV 1/2. Except for the sensitivity of Uni-gold® HIV 1/2, the performances of 2 tests were acceptable and in perfect agreement with the reference tests. These results require a revision of the algorithm. In addition, an exploration in molecular biology is indicated to determine the subtypes of the HIV strains of the 4 samples that tested false negative with Uni-gold® HIV 1/2.