The impact of past HIV interventions and diagnosis gaps on new HIV acquisitions, transmissions, and HIV-related deaths in Côte d'Ivoire, Mali, and Senegal.

OBJECTIVES: To estimate the epidemiological impact of past HIV interventions and the magnitude and contribution of undiagnosed HIV among different risk groups on new HIV acquisitions in Côte d'Ivoire, Mali and Senegal. DESIGN: HIV transmission dynamic models among the overall population and key populations [female sex workers (FSW), their clients, and MSM]. METHODS: Models were independently parameterized and calibrated for each set of country-specific demographic, behavioural, and epidemiological data. We estimated the fraction of new HIV infections over 2012-2021 averted by condom use and antiretroviral therapy (ART) uptake among key population and nonkey population, the direct and indirect contribution of specific groups to new infections [transmission population-attributable fraction (tPAF)] over 2012-2021 due to prevention gaps, and the distribution of undiagnosed PWH by risk group in January 2022 and their tPAF over 2022-2031. RESULTS: Condom use and ART may have averted 81-88% of new HIV infections over 2012-2021 across countries, mostly because of condom use by key population. The tPAF of all key populations combined over 2012-2021 varied between 27% (Côte d'Ivoire) and 79% (Senegal). Male key population (clients of FSW and MSM) contributed most to new infections (>60% in Mali and Senegal) owing to their higher HIV prevalence and larger prevention gaps. In 2022, men represented 56% of all PWH with an undiagnosed infection in Côte d'Ivoire (male key population = 15%), 46% in Mali (male key population = 23%), and 69% in Senegal (male key population = 55%). If HIV testing and ART initiation rates remain at current levels, 20% of new HIV infections could be due to undiagnosed key population PWH in Côte d'Ivoire over 2022-2031, 53% in Mali, and 65% in Senegal. CONCLUSION: Substantial HIV diagnosis gaps remain in Western Africa, especially among male key population. Addressing these gaps is key to impacting the HIV epidemics in the region and achieving the goal of ending AIDS by 2030.

Potential population-level effects of HIV self-test distribution among key populations in Côte d'Ivoire, Mali, and Senegal: a mathematical modelling analysis.

BACKGROUND: During 2019-21, the AutoTest VIH, Libre d'accéder à la connaissance de son Statut (ATLAS) programme distributed around 380 000 HIV self-testing kits to key populations, including female sex workers, men who have sex with men, and their partners, in Côte d'Ivoire, Mali, and Senegal. We aimed to estimate the effects of the ATLAS programme and national scale-up of HIV self-test distribution on HIV diagnosis, HIV treatment coverage, HIV incidence, and HIV-related mortality. METHODS: We adapted a deterministic compartmental model of HIV transmission in Côte d'Ivoire, parameterised and fitted to country-specific demographic, behavioural, HIV epidemiological, and intervention data in Côte d'Ivoire, Mali, and Senegal separately during 1980-2020. We simulated dynamics of new HIV infections, HIV diagnoses, and HIV-related deaths within scenarios with and without HIV self-test distribution among key populations. Models were separately parameterised and fitted to country-specific sets of epidemiological and intervention outcomes (stratified by sex, risk, age group, and HIV status, if available) over time within a Bayesian framework. We estimated the effects on the absolute increase in the proportion of people with HIV diagnosed at the end of 2021 for the ATLAS-only scenario and at the end of 2028 and 2038 for the HIV self-testing scale-up scenario. We estimated cumulative numbers of additional HIV diagnoses and initiations of antiretroviral therapy and the proportion and absolute numbers of new HIV infections and HIV-related deaths averted during 2019-21 and 2019-28 for the ATLAS-only scenario and during 2019-28 and 2019-38 for the HIV self-testing scale-up scenario. FINDINGS: Our model estimated that ATLAS could have led to 700 (90% uncertainty interval [UI] 500-900) additional HIV diagnoses in Côte d'Ivoire, 500 (300-900) in Mali, and 300 (50-700) in Senegal during 2019-21, a 0·4 percentage point (90% UI 0·3-0·5) increase overall by the end of 2021. During 2019-28, ATLAS was estimated to avert 1900 (90% UI 1300-2700) new HIV infections and 600 (400-800) HIV-related deaths across the three countries, of which 38·6% (90% UI 31·8-48·3) of new infections and 70·1% (60·4-77·3) of HIV-related deaths would be among key populations. ATLAS would avert 1·5% (0·8-3·1) of all HIV-related deaths across the three countries during this period. Scaling up HIV self-testing would avert 16·2% (90% UI 10·0-23·1) of all new HIV infections during 2019-28 in Senegal, 5·3% (3·0-8·9) in Mali, and 1·6% (1·0-2·4) in Côte d'Ivoire. HIV self-testing scale-up among key populations was estimated to increase HIV diagnosis by the end of 2028 to 1·3 percentage points (90% UI 0·8-1·9) in Côte d'Ivoire, 10·6 percentage points (5·3-16·8) in Senegal, and 3·6 percentage points (2·0-6·4) in Mali. INTERPRETATION: Scaling up HIV self-test distribution among key populations in western Africa could attenuate disparities in access to HIV testing and reduce infections and deaths among key populations and their partners. FUNDING: Unitaid, Solthis, the UK Medical Research Council Centre for Global Infectious Disease Analysis, the EU European & Developing Countries Clinical Trials Partnership programme, and the Wellcome Trust. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.