Robust tests for recent HIV infection (as opposed to just HIV infection) would substantially reduce the enormous challenges of estimating HIV incidence (the rate of occurrence of new infections). This article of SACEMA and the related Policy Brief provides the results of the first independent evaluation of five incidence assays conducted by the Consortium for the Evaluation and Performance of HIV Incidence Assays.
The headline-grabber at the 20th Conference for Retroviruses and Opportunistic Infections (CROI) was the ‘functional cure’ of an HIV-infected child. A key success of the ‘Mississippi miracle’ is that no latent reservoir of replication-competent HIV developed in the infant. The study of latent reservoirs, and prospects for eliminating these through treatment, in adults and infants, was the topic of many sessions. Apart from the laboratory science, a number of results from studies and modelling exercises were presented, assessing a number of risk factors and interventions for various conditions. Of particular relevance to the work of SACEMA is the topic of HIV incidence estimation. CEPHIA hosted a satellite session, focussed on the first independent assessments of incidence assays for HIV incidence estimation in cross-sectional studies.
There are a number of approaches for estimating HIV incidence, with varying tractability, complexity and limitations. In recent years, there has been considerable interest in estimating HIV incidence from single cross-sectional surveys testing for ‘recent infection’ through laboratory-measured host or viral biomarkers. In a survey, the sizes of the HIV-negative, ‘recently infected’ and ‘non-recently infected’ populations can be measured, and incidence estimated using knowledge of the dynamics of the ‘recent infection’ biomarker. However, two key obstacles to cross-sectional biomarker-based incidence surveillance remain: the lack of standardisation of terminology and methodology, and poor characteristics, and characterisation, of currently available tests.