Trends in knowledge of HIV status and efficiency of HIV testing services in Sub-Saharan Africa (2000-2020): a modelling study of survey and HIV testing program data

Background Knowledge of HIV status (KOS) among people living with HIV (PLHIV) is essential for an effective national HIV response. This study estimates progress and gaps in reaching the UNAIDS 2020 target of 90% KOS, and the efficiency of HIV testing services (HTS) in sub-Saharan Africa (SSA), where two thirds of all PLHIV live. Methods We used data from 183 population-based surveys (N=2.7 million participants) and national HTS programs (N=315 country-years) from 40 countries as inputs into a mathematical model to examine trends in KOS among PLHIV, median time from HIV infection to diagnosis, HIV testing positivity, and proportion of new diagnoses among all positive tests, adjusting for retesting. Findings Across SSA, KOS steadily increased from 6% (95% credible interval [95%CrI]: 5% to 7%) in 2000 to 84% (95%CrI: 82% to 86%) in 2020. Twelve countries and one region, Southern Africa, reached the 90% target. In 2020, KOS was lower among men (79%) than women (87%) across SSA. PLHIV aged 15-24 years were the least likely to know their status (65%), but the largest gap in terms of absolute numbers was among men aged 35-49 years, with over 700,000 left undiagnosed. As KOS increased from 2000 to 2020, the median time to diagnosis decreased from 10 to 3 years, HIV testing positivity declined from 9% to 3%, and the proportion of first-time diagnoses among all positive tests dropped from 89% to 42%. Interpretation On the path towards the next UNAIDS target of 95% diagnostic coverage by 2030, and in a context of declining positivity and yield of first-time diagnoses, we need to focus on addressing disparities in KOS. Increasing KOS and treatment coverage among older men could be critical to reduce HIV incidence among women in SSA, and by extension, reducing mother-to-child transmission. ### Competing Interest Statement We acknowledge funding from the Steinberg Fund for Interdisciplinary Global Health Research (McGill University), the Canadian Institutes of Health Research, and the Bill and Melinda Gates Foundation. MMG holds a Canada Research Chair (Tier 2) in Population Health Modeling and reports other from UNAIDS, other from WHO, grants from Gilead Sciences Inc., outside the submitted work; KG reports a Postdoctoral Fellowship from Fonds de recherche du Québec - Santé, during the conduct of the study; personal fees from UNAIDS, outside the submitted work; JWE reports grands from Bill and Melinda Gates Foundation, grants from UNAIDS, grants from UK Medical Research Council, during the conduct of the study; grants from NIH, grants from UNAIDS, grants from WHO, personal fees from WHO, grants from USAID, outside the submitted work; All other authors has nothing to disclose. The contents in this article are those of the authors and do not necessarily reflect the view of the World Health Organization. ### Funding Statement We acknowledge funding from the Steinberg Fund for Interdisciplinary Global Health Research (McGill University), the Canadian Institutes of Health Research, and the Bill and Melinda Gates Foundation. MMG holds a Canada Research Chair (Tier 2) in Population Health Modeling and reports other from UNAIDS, other from WHO, grants from Gilead Sciences Inc., outside the submitted work; KG reports a Postdoctoral Fellowship from Fonds de recherche du Québec - Santé, during the conduct of the study; personal fees from UNAIDS, outside the submitted work; JWE reports grands from Bill and Melinda Gates Foundation, grants from UNAIDS, grants from UK Medical Research Council, during the conduct of the study; grants from NIH, grants from UNAIDS, grants from WHO, personal fees from WHO, grants from USAID, outside the submitted work; All other authors has nothing to disclose. The contents in this article are those of the authors and do not necessarily reflect the view of the World Health Organization. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: All analyses were performed on anonymized and deidentified data. All DHS/AIS survey protocols have been approved by the Internal Review Board of ICF International in Calverton (USA) and by the relevant country authorities for other surveys (MICS and PHIA). Further information on the ethics approval can be found in the individual country reports. Ethics approval for secondary data analyses was obtained from McGill University's Faculty of Medicine Institutional Review Board (A10-E72-17B). All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes For the analyses reported here, we used the Shiny90 country files submitted to UNAIDS in 2020 ([www.unaids.org/en/dataanalysis/datatools/spectrum-epp][1]), including Spectrum, surveys, and program data. Sources of national household surveys included Demographic and Health Surveys (DHS; ), AIDS Indicator Surveys (AIS), Multiple Indicator Cluster Surveys (MICS; [www.mics.unicef.org/surveys][2]), Population-based HIV Impact Assessments (PHIA; ), and other country-specific surveys (Figure 1). [1]: http://www.unaids.org/en/dataanalysis/datatools/spectrum-epp [2]: http://www.mics.unicef.org/surveys