An Accurate and Rapid Laboratory Testing Algorithm for the Diagnosis of HIV Infection for Decentralisation: Use of A Rapid Fourth Generation Test as a Second-line Test

For the accurate and early diagnosis of Human Immunodeficiency virus (HIV), the classical laboratory testing algorithm that included Western Blot (WB) as the confirmatory test has been replaced by another one, the Centers for Disease Control and Prevention (CDC) algorithm that includes testing the fourth generation enzyme immunoassay (EIA) reactive samples with a rapid HIV-1/2 antibody differentiating second-line test, followed by HIV-1 nucleic acid amplification test (NAT) in the case of non-reactive or indeterminate second test result.The aim of the study was to evaluate the utility of a fourth generation rapid test as an alternative for antibody differentiation test in the second step of a three step diagnostic algorithm.The specificity and sensitivity of new version Alere HIV Combo test as the second test in the algorithm was evaluated by using 130 EIA negative and 123 4th generation EIA repeteadly reactive and WB positive sera, respectively.All of 130 sera that were negative by 4th generation EIA were non-reactive by Alere HIV Combo test resulting in the specificity of 100%.The sensitivity of the rapid test was found to be 100% because 123 sera that were 4th generation EIA repeatedly reactive and WB positive were all found to be reactive.Alere HIV Combo, a fourth generation rapid test with 100% sensitivity and specificity, can reliably be considered as a second-line test in the algorithm in which the non-reactive samples should be tested by HIV-1 NAT.