The Asanté HIV-1 Rapid Recency assay\'s \'verification\' line detected HIV infection a median of 18 days later than a nucleic acid detection assay and performed similarly to 19 other existing rapid HIV antibody tests. Pending regulatory approval, the assay could be an option with other rapid tests in national HIV-1 testing algorithms, which would allow collection of HIV recency data as part of a national screening program without requiring additional testing.

Incidence estimation of HIV infection can be performed using recent infection testing algorithm (RITA) results from a cross-sectional sample. This allows practitioners to understand population trends in the HIV epidemic without having to perform longitudinal follow-up on a cohort of individuals. The utility of the approach is limited by its precision, driven by the (low) sensitivity of the RITA at identifying recent infection. By utilizing results of previous HIV tests that individuals may have taken, we consider an enhanced RITA with increased sensitivity (and specificity). We use it to propose an enhanced estimator for incidence estimation. We prove the theoretical properties of the enhanced estimator and illustrate its numerical performance in simulation studies. We apply the estimator to data from a cluster-randomized trial to study the effect of community-level HIV interventions on HIV incidence. We demonstrate that the enhanced estimator provides a more precise estimate of HIV incidence compared to the standard estimator.

BACKGROUND: Testing for recent HIV infection can distinguish recently acquired infection from long-standing infections. Given current interest in the implementation of recent infection testing algorithms (RITA), we report our experiences in implementing a RITA in three pilot studies and highlight important issues to consider when conducting recency testing in routine settings.
METHODS: We applied a RITA, incorporating a limited antigen (LAg) avidity assay, in different routine HIV service-delivery settings in 2018: antenatal care clinics in Siaya County, Kenya, HIV testing and counselling facilities in Nairobi, Kenya, and female sex workers clinics in Zimbabwe. Discussions were conducted with study coordinators, laboratory leads, and facility-based stakeholders to evaluate experiences and lessons learned in relation to implementing recency testing.
RESULTS: In Siaya County 10/426 (2.3%) of women testing HIV positive were classified as recent, compared to 46/530 (8.7%) of women and men in Nairobi and 33/313 (10.5%) of female sex workers in Zimbabwe. Across the study setting, we observed differences in acceptance, transport and storage of dried blood spot (DBS) or venous blood samples. For example, the acceptance rate when testing venous blood was 11% lower than when using DBS. Integrating our study into existing services ensured a quick start of the study and kept the amount of additional resources required low. From a laboratory perspective, the LAg avidity assay was initially difficult to operationalise, but developing a network of laboratories and experts to work together helped to improve this. A challenge that was not overcome was the returning of RITA test results to clients. This was due to delays in laboratory testing, the need for multiple test results to satisfy the RITA, difficulties in aligning clinic visits, and participants opting not to return for test results.
CONCLUSIONS: We completed three pilot studies using HIV recency testing based on a RITA in Kenya and Zimbabwe. The main lessons we learned were related to sample collection and handling, LAg avidity assay performance, integration into existing services and returning of test results to participants. Our real-world experience could provide helpful guidance to people currently working on the implementation of HIV recency testing in sub-Saharan Africa.

To enable an up-to-date molecular analysis of human immunodeficiency virus (HIV) genotypes circulating in Germany we have established a surveillance system based on recently acquired HIV infections. New HIV infections are reported to the Robert Koch Institute as a statutory duty for anonymous notification. In 2013 and 2014, a dried serum spot (DSS) sample was received from 6,371 newly diagnosed HIV-cases; their analysis suggested that 1,797 samples originated from a recent infection. Of these, 809 were successfully genotyped in the pol region to identify transmitted drug resistance (TDR) mutations and to determine the HIV-1 subtype. Total TDR was 10.8%, comprising 4.3% with mono-resistance to nucleoside reverse transcriptase inhibitors (NRTIs), 2.6% to non-NRTIs, 3.0% to protease inhibitors and 0.6% and 0.2%, respectively, with dual- and triple-class resistances. HIV-1 subtype B was most prevalent with 77.0%. Non-B infections were identified more often in men and women with heterosexual transmission compared with intravenous drug users or men who have sex with men (79% and 76%, 33%, 12%; all p < 0.05). Non-B subtypes were also more frequently found in patients originating from countries other than Germany (46% vs 14%; p < 0.05) and in patients infected outside of Germany (63% vs 14%; p < 0.05).