Proportion of samples classified as assay positive using the LAg-Avidity assay alone or with HIV viral load, as a function of the duration of HIV infection.

<p>Probability curves were generated by analyzing samples from three cohort studies (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0082772#s2" target="_blank">Methods</a>). (A) Probability curves generated using the LAg-Avidity assay with four different assay cutoffs (0.5, 1.0, 1.5, and 3.0 normalized optical density units [OD-n]). Samples were classified as assay positive if the LAg-Avidity assay result was below the assay cutoff. (B) Probability curves generated using the MAAs shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0082772#pone-0082772-g002" target="_blank">Figure 2</a>. Samples were classified as MAA positive if results from each of the component assays met the requirements of the MAA.