
Independent assessment of candidate HIV incidence assays on specimens in the CEPHIA repository. Cross-sectional HIV incidence surveillance, using assays that distinguish 'recent' from 'nonrecent' infections, has been hampered by inadequate performance and characterization of incidence assays. In this study, the Consortium for the Evaluation and Performance of HIV Incidence Assays presents results of the first independent evaluation of five incidence assays (BED, limiting antigen avidity, less-sensitive Vitros, Vitros avidity and BioRad avidity). A large repository of diverse specimens from HIV-positive patients was established, multiple assays were run on 2500 selected specimens, and data were analyzed to estimate assay characteristics relevant for incidence surveillance. The mean duration of recent infection (average time 'recent' while infected for less than some time cut-off T) was estimated from longitudinal data on seroconverters by regression. The false-recent rate (FRR, probability of testing 'recent' when infected for longer than T) was explored by measuring the proportions of 'recent' results in various subsets of patients.