Final sample classification, HIV prevalence, and estimated annual HIV incidence.

Abbreviations: MAA: multi-assay algorithm; ARV: antiretroviral drug.aThe HIV status of study participants was initially characterized based on the results of the two HIV rapid tests performed in-country (see Methods). The testing algorithms used to classify samples according to HIV infection status are shown in Figures 1 and 2.bSamples classified as MAA positive (see Figure 1) were tested for the presence of ARV drugs (see text).cTwo samples did not have sufficient volume remaining for testing and four samples failed testing; these were included in the analysis as incident infections.dIncident infections include acute infections, early infections (confirmed infections with indeterminate Western blots), and established infections classified MAA positive (see Figure 2) that either had no ARV drugs detected or no ARV test result (shown in bold).