Can HIV recent infection surveillance help us better understand where primary prevention efforts should be targeted? Results of three pilots integrating a recent infection testing algorithm into routine programme activities in Kenya and Zimbabwe

Abstract

IntroductionSurveillance of recent HIV infections in national testing services has the potential to inform primary prevention programming activities. Focusing on procedures required to accurately determine recent infection, and the potential for recent infection surveillance to inform prevention efforts, we present the results of three independent but linked pilots of recency testing.MethodsTo distinguish recently acquired HIV infection from long‐standing infection, in 2018 we applied a Recent Infection Testing Algorithm that combined a laboratory‐based Limiting Antigen Avidity Enzyme Immunoassay with clinical information (viral‐load; history of prior HIV diagnosis; antiretroviral therapy‐exposure). We explored potential misclassification of test results and analysed the characteristics of participants with recent infection. We applied the algorithm in antenatal clinics providing prevention of mother‐to‐child transmission services in Siaya County, Kenya, outreach sites serving female sex workers in Zimbabwe, and routine HIV testing and counselling facilities in Nairobi, Kenya. In Nairobi, we also conducted recency testing among partners of HIV‐positive participants.ResultsIn Siaya County, 2.3% (10/426) of HIV‐positive pregnant women were classified as recent. A risk factor analysis comparing women testing recent with those testing HIV‐negative found women in their first trimester were significantly more likely to test recent than those in their second or third trimester. In Zimbabwe, 10.5% (33/313) of female sex workers testing HIV‐positive through the outreach programme were classified recent. A risk factor analysis of women testing recent versus those testing HIV‐negative, found no strong evidence of an association with recent infection. In Nairobi, among 532 HIV‐positive women and men, 8.6% (46) were classified recent. Among partners of participants, almost a quarter of those who tested HIV‐positive were classified as recent (23.8%; 5/21). In all three settings, the inclusion of clinical information helped improve the positive predictive value of recent infection testing by removing cases that were likely misclassified.ConclusionsWe successfully identified recently acquired infections among persons testing HIV‐positive in routine testing settings and highlight the importance of incorporating additional information to accurately classify recent infection. We identified a number of groups with a significantly higher proportion of recent infection, suggesting recent infection surveillance, when rolled‐out nationally, may help in further targeting primary prevention efforts.

Experiences and lessons learned from the real-world implementation of an HIV recent infection testing algorithm in three routine service-delivery settings in Kenya and Zimbabwe

“…Across 34 pilot sites, in total 1269 people testing HIV positive completed the RITA, of whom 89 (7.0%) were classified as positive for recent infection. A detailed description of the test results (quantitative focus) have been presented elsewhere [17].…”

“…Together, this provided a picture of how the study was conducted in actuality and how it could be improved in the future. A more detailed description of this study has been provided elsewhere [17].…”

Use of HIV Recency Assays for HIV Incidence Estimation and Non-Incidence Surveillance Use Cases: A systematic review

“…Among non-incidence use cases, seven [91][92][93][94][95][96][97] described case-based surveillance among new HIV diagnoses in routine HIV programme settings and 2 described recency testing to inform targeted prevention planning, including one from a population-level cohort study 90 and one that described use of recency testing within three separate routine HIV country programs. 98 The quality of evidence was at least "moderately strong" in all 9/9 non-incidence use cases, each identified from the peer-reviewed literature. Each of these 9 articles used proportion testing recent and/or odds for recently acquired infection as the primary outcome measures.…”

Differentiated Prevention And Care To Reduce The Risk of HIV Acquisition And Transmission Among Female Sex Workers In Zimbabwe: Study Protocol For The ‘AMETHIST’ Cluster Randomised Trial

“…Results of HIV and Syphilis rapid tests will be returned to all participants on site. All women will have two dried blood spot samples (DBS) collected for HIV viral load testing, LAg avidity assay testing (for incorporation into a recent infection testing algorithm) [25] at the Flow Cytometry Laboratory, Harare. Results of viral load tests will be made available to women within 4 weeks of the survey.…”