Short Communication: Low False Recent Rate of Limiting Antigen-Avidity Assay Combined with HIV-1 RNA Data in Botswana

Cross-sectional estimation of HIV incidence could misclassify some established or chronic HIV infections as recent. Usually long-term nonprogressors, elite and viremic controllers, and individuals on ART contribute to misclassification. Local data on the false recent rate (FRR) could minimize misclassification during estimation of HIV incidence. To improve monitoring of HIV incidence, we estimated local FRR in Botswana. A total of 1,036 specimens from individuals infected for at least 1.5-2 years were sampled between 2004 and 2009 and tested using the limiting antigen (LAg)-avidity assay using a cutoff of 1.5 normalized optical density units. The FRR was 0.97% (10/1,036; 95% confidence interval [CI] 0.46-1.77). Four samples had HIV-1 RNA >1,000 cps/ml, giving an adjusted FRR of 0.39% (4/1,036; 95% CI 0.11-0.99). A combination of LAg and HIV-1 RNA load data resulted in FRR below 1% in the Botswana population.

Performance of rapid HIV testing by lay counselors in the field during the behavioral and biological surveillance survey among female sex workers and men who have sex with men in Botswana

: The study assessed the performance of rapid HIV testing with whole blood using Kehua Bio-engineering HIV (1 + 2) and Uni-Gold HIV test kits by trained and certified lay counselors, offered to female sex workers and men who have sex with men during the 2012 survey fieldwork. The results of rapid HIV testing were compared with enzyme-linked immunosorbent assay testing performed in a parallel algorithm at the HIV Reference Laboratory. The sensitivity and the specificity of rapid HIV testing were high for men who have sex with men and female sex workers, with 98.1% and 100%, and 98.2% and 98.5%, respectively. Misclassifications occurred with rapid testing.