Evaluation of rapid assays for screening and confirming HIV-1 infection in Ethiopia

To evaluate a simple and rapid testing strategy to diagnose HIV infection in Ethiopia, we subjected a panel of 688 sera with known HIV serologic status (confirmed by ELISA/WB or double ELISA) to 3 rapid assays: Determine HIV-1/2, Capillus HIV-1/2 and Serocard HIV. Samples were obtained from participants in a cohort study on HIV-infection (72%), from tuberculosis patients (18%) and from participants in surveillance studies among police recruits and commercial sex workers (10%). The panel consisted of 249 HIV-1 positive samples, of which 68 were HIV-1 subtype C and 1 HIV-1 subtype A, and 439 HIV-1 negative samples. Determine and Capillus were 100% sensitive and 99.8% specific, Serocard was 100% sensitive and specific. On retrospective evaluation, both parallel (samples tested simultaneously by two rapid assays) and serial (samples tested by two consecutive rapid assays) testing algorithms were 100% sensitive and specific when compared to ELISA/WB or double ELISA testing strategy. In conclusion rapid assays have high sensitivity and specificity. HIV serodiagnosis based on rapid assays may therefore be a valuable alternative in voluntary counselling and testing centres and in facilities where sophisticated laboratories are not available.