BACKGROUND:Awareness of HIV status is crucial for accessing HIV care and prevention but remains suboptimal in West Africa. The ATLAS initiative, launched in Côte d'Ivoire, Mali, and Senegal, addressed this gap by distributing approximately 380,000 HIV self-testing (HIVST) kits from 2019 to 2021, primarily to key populations and their social networks. This study assessed levels and correlates of Knowledge, Attitudes, and Practices (KAP) related to HIVST in the Bas-Sassandra region of Côte d'Ivoire following ATLAS's introduction. METHOD:A cross-sectional population-based survey was conducted in the Bas-Sassandra region in 2021 among individuals aged 15-49. A total of 6,271 people (3,203 men and 3,068 women) were interviewed. They were selected using a three-stage stratified sampling approach in the Bas-Sassandra region. Bivariate statistics and multivariable logistic regressions were used to assess KAP levels and the associated factors. RESULTS:Although few participants reported having heard about HIVST (11%) or having used it (3%), most of them reported that if it were freely available, they would be interested/very interested in using it for themselves (76%), as well as for their sexual partners (75%). Education and wealth were positively associated with knowledge and positive attitudes towards HIVST among both men and women, whereas age was positively correlated to knowledge and use of HIVST among men only. The number of sexual partners over the last 12 months was positively associated with knowledge of HIVST and willingness to use HIVST for themselves or their sexual partners among both sexes. We also found that high HIV-related knowledge and low levels of negative attitude were positively associated with positive attitudes towards HIVST, while exposure to the media appeared to be correlated to knowledge of HIVST. CONCLUSION:The high level of positive attitudes towards HIVST calls for a scaling up of access to HIVST in the region. Specific attention to groups with the worst KAP, such as the less educated, the poor or those with more HIV-related negative attitude, could enhance the success of such initiatives.

Background. Characterising disparities in HIV infection across populations by gender, age, and HIV risk is key information to guide intervention priorities. We compared 9 models representing 15 different settings across Africa to assess how indicators measuring HIV acquisitions, transmissions, or potential long-term infections influence estimates of the contribution of different populations to new infections, including key populations (KPs, including female sex workers (FSW), their clients, men who have sex with men). Methods. We evaluated four indicators: I1) acquisition indicator measuring the annual fraction of all new infections acquired by a specific population, I2) direct transmission indicator measuring the annual fraction of all new infections directly transmitted by a specific population, I3) 1-year and I4) 10-year transmission population-attributable fractions (tPAFs). tPAFs measure the fraction of new infections averted if transmission involving a specific population was blocked over a specific time period. We compared estimates of the four indicators across 7 populations and 15 settings and assessed if the contribution of specific populations is ranked differently across indicators for 10 settings. Findings. Indicators identified distinct priority populations as the largest contributors: The acquisition indicator (I1) identified women aged 25+ years outside KPs as contributing the most to acquired infections in 8/10 settings in 2020, but to direct transmissions (I2) in only two settings. In 6/10 settings, the 10-year tPAFs (I4) identified non-KP men aged 25+ years and clients of FSW as the largest contributors to HIV transmission. Notably, non-KP women aged 15-24 years acquired (I1) more infections in 2020 (median of 1.7-fold across models) than they directly transmitted (I2), while non-KP men aged 25+ years and clients of FSWs transmitted more infections than they acquired in all but one model (median: 1.4 and 1.6-fold, respectively). Estimates of the 10-year tPAFs accounting for transmission in the long-term were substantially larger than the direct transmission indicator for all populations, especially for FSW (median: 2.0-fold). Interpretation. Indicators that reflect HIV acquisitions and transmissions over the short and long term can be utilised to capture the complexity of HIV epidemics across different populations and timeframes. The added nuance would improve the effectiveness of the HIV prevention response across all populations at risk. Funding. NIH, MRC. ### Competing Interest Statement JWI-E reports research grants from the Gates Foundation, the US National Institutes of Health, UNAIDS, and UK Research and Innovation; personal fees from BAO Systems; and support for meeting travel from UNAIDS, the International AIDS Society, and the Gates Foundation, all outside the submitted work. MCB reports research funding for unrelated projects from the Wellcome Trust and CIHR. RSt reports unrelated contracts with the Gates Foundation. The remaining authors have no conflicts of interest to disclose. ### Funding Statement Supported partly by UNAIDS and the HPTN Modelling Centre, which is funded by the U.S. National Institutes of Health (NIH UM1 AI068617) through HPTN. RSi, RDB, KMM, JSta, OS, JWI-E and M-CB acknowledge funding from the MRC Centre for Global Infectious Disease Analysis (reference MR/X020258/1), funded by the UK Medical Research Council (MRC). This UK funded award is carried out in the frame of the Global health EDCTP3 Joint Undertaking. RSi, JSton, PV, M-CB and MM-G acknowledge funding from the Wellcome Trust (WT 226619/Z/22/Z). MM-G and SM's research program are supported by Tier 2 Canada Research Chairs in Population Health Modeling and Mathematical Modeling and Program Science, respectively. AB was supported by the US National Institutes of Health (NIH R01AI179417). Support for EMOD-HIV and Thembisa was provided by the Gates Foundation. Country models utilized for Optima HIV have been supported by the Gates Foundation, Global Fund, and the World Bank. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. 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, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The model estimates that support the findings of this analysis are available from the corresponding author upon reasonable request, after consultation with the modelling teams.

BACKGROUND:In January, 2025, the US Government issued a directive, pausing all foreign aid programmes. This directive included a 90-day pausing of all US President's Emergency Plan for AIDS Relief (PEPFAR) funding for HIV oral pre-exposure prophylaxis (PrEP) except for pregnant and breastfeeding women, with a return to funding for PrEP looking increasingly unlikely. We aimed to estimate the impact of a funding pause for PrEP on HIV infections in sub-Saharan Africa. METHODS:In this mathematical modelling study, we developed a static HIV transmission model incorporating PrEP, parameterised with estimates of population size, HIV prevalence and incidence, and PrEP effectiveness for different subpopulations (including key populations) in each PEPFAR-funded sub-Saharan African country. Key populations were men who have sex with men, female sex workers, transgender women, and people who inject drugs. We used PEPFAR reporting on numbers of people in different subpopulations returning for oral PrEP for each country in July to September, 2024, as the estimated number using oral PrEP provided by PEPFAR. For each country and subpopulation, we modelled the relative and absolute increase in new primary HIV infections resulting from removing this funded PrEP for a year and the number of secondary infections that could result from these primary infections during the next 5 years. FINDINGS:Towards the end of 2024, 719 384 individuals who were not breastfeeding or pregnant, including 205 868 people from key populations, received PEPFAR-funded PrEP across 28 sub-Saharan African countries. The estimated proportion of HIV-negative key population individuals receiving PEPFAR-funded PrEP (ie, the coverage) ranged from 2·6% (95% uncertainty interval 2·0-3·4) in people who inject drugs to 5·0% (4·5-5·9) in female sex workers. Estimated coverage among non-key population men was less than 0·1% (<0·1 to <0·1) and in women was 0·1% (0·1 to 0·1). Stopping PEPFAR's provision of PrEP for a year could lead to 6671 (5032-8192) additional new primary HIV infections, including 5663 (4146-7074) in key populations. Within key populations, this absolute increase corresponds to relative increases in new HIV infections of 0·8% (0·3-1·5) in people who inject drugs, 1·4% (0·8-2·3) in transgender women, 2·2% (1·3-3·0) in men who have sex with men, and 2·9% (1·8-4·4) in female sex workers. In Zambia, the country with the highest PEPFAR coverage across all key populations, this increase ranges from 7·8% (2·5-17·1) in people who inject drugs to 18·1% (9·7-33·2) in men who have sex with men. When considering secondary transmissions, we estimated that a 1-year pause could lead to 10 313 (7796-12 921) additional infections during the next 5 years. INTERPRETATION:Our projections show the substantial detrimental impacts that cuts to PEPFAR funding could have. Mitigation measures, including funding through alternative international donors or domestic government budgets, are needed to maintain and increase existing coverage levels of PrEP and therefore prevent the detrimental impact of PEPFAR's funding cuts, particularly in high coverage countries. FUNDING:Wellcome Trust. TRANSLATION:For the French translation of the abstract see Supplementary Materials section.

BACKGROUND:Characterising disparities in HIV infection across populations by gender, age, and HIV risk is key information to guide intervention priorities. We aimed to assess how indicators measuring HIV acquisitions, transmissions, or potential long-term infections influence estimates of the contribution of different populations to new infections, including key populations (including female sex workers, their clients, men who have sex with men). METHODS:In this mathematical model comparison analysis, we evaluated four indicators using nine models representing 15 different settings across Africa. The acquisition indicator (I1) measured the annual proportion of all new infections acquired by a specific population, the direct transmission indicator (I2) measured the annual proportion of all new infections directly transmitted by a specific population, and the 1-year transmission population-attributable fractions (tPAFs; I3) and 10-year tPAFs (I4) measured the proportion of new infections averted if transmission involving a specific population was blocked over a specific time period. We compared estimates of the four indicators across seven populations and 15 settings and assessed if the contribution of specific populations ranked differently across indicators for ten settings. FINDINGS:Different indicators identified distinct priority populations as the largest contributors: I1 identified women aged 25 years and older outside key populations as contributing the most to acquired infections in eight of ten settings in 2020, but to direct transmissions (I2) in only two settings. In six of ten settings, I4 identified non-key population men aged 25 years and older and clients of female sex workers as the largest contributors to HIV transmission. Notably, non-key population women aged 15-24 years acquired (I1) more infections in 2020 (median of 1·7 times higher across models) than they directly transmitted (I2), whereas more infections were transmitted than acquired in non-key population men aged 25 years and older (median 1·4 times more) and clients of female sex workers (1·6 times more) in all but one model. Estimates of the 10-year tPAFs accounting for transmission in the long-term were substantially larger than the direct transmission indicator for all populations, especially for female sex workers (2·0 times higher). INTERPRETATION:Indicators that reflect HIV acquisitions and transmissions in the short and long term can be used to capture the complexity of HIV epidemics across different populations and timeframes. The added nuance would improve the effectiveness of the HIV prevention response across all populations at risk. FUNDING:US National Institutes of Health and UK Medical Research Council. TRANSLATION:For the French translation of the abstract see Supplementary Materials section.

BACKGROUND:Oral HIV pre-exposure prophylaxis (PrEP) can effectively reduce HIV incidence. A 2020-21 demonstration project assessed the feasibility and health outcomes of offering oral PrEP to men who have sex with men (MSM) in Cotonou, Benin. We evaluated the epidemiological impact and cost-effectiveness of this project and the potential scale-up of oral HIV PrEP for MSM in Cotonou. METHODS:We calibrated an HIV transmission-dynamic model structured by age and risk within a Bayesian framework to MSM-specific HIV prevalence and treatment data, parameterised with project behavioural and cost (including PrEP drug, implementation, and HIV care costs) data. We estimated the impact and cost-effectiveness of the 2020-21 Cotonou demonstration project (PrEP coverage, 5-10% of all MSM who are not living with HIV in Grand Cotonou; and adherence, 13-21% taking at least four of seven required doses [ie, at least four doses per week for daily users and at least four of seven expected doses given reported sexual activity for on-demand users]) and of its potential scale-up over 5 years (from 2022 to 2027), reaching 30% coverage of MSM in Grand Cotonou and with demonstration project adherence levels. We additionally modelled ideal PrEP adherence (100% taking at least four of seven required doses). We estimated the percentage of cumulative new HIV infections averted among participating MSM over 1 year and among all MSM in Grand Cotonou and their female partners over 20 years, and cost-effectiveness as cost per disability-adjusted life-year (DALY) averted over 20 years. Costs and DALYs were discounted 3% annually. FINDINGS:We found that the demonstration project averted an estimated 21·5% (95% uncertainty interval 16·6 to 26·2) of HIV infections among participants over 1 year. With ideal adherence, cases that would be averted increased to 95·2% (90·8 to 98·8). A 5-year PrEP scale-up could avert 3·2% (1·6 to 4·8) of HIV infections among all MSM and female partners over 20 years, at US$388 (36 to 2792) per DALY averted. With ideal adherence, this decreased to -$28 (-126 to 589) per DALY averted. INTERPRETATION:Low adherence to PrEP restricted the impact of the demonstration project. At 30% coverage among MSM by 2027, PrEP scale-up would be cost-effective at a $1225 threshold with 86·6% probability, and it could be more cost-effective if high adherence could be reached without substantially increasing costs. FUNDING:Canadian Institutes of Health Research and US National Institutes of Health. TRANSLATION:For the French translation of the abstract see Supplementary Materials section.

Background Consultations for sexually transmitted infection (STI) provide an opportunity to offer HIV testing to both patients and their partners. This study describes the organisation of HIV self-testing (HIVST) distribution during STI consultations in Abidjan (Côte d’Ivoire) and analyse the perceived barriers and facilitators associated with the use and redistribution of HIVST kits by STI patients. Materials and methods A qualitative study was conducted between March and August 2021 to investigate three services providing HIVST: an antenatal care clinic (ANC), a general health centre that also provided STI consultations, and a dedicated STI clinic. Data were collected through observations of medical consultations with STI patients ( N = 98) and interviews with both health professionals involved in HIVST distribution ( N = 18) and STI patients who received HIVST kits for their partners ( N = 20). Results In the ANC clinic, HIV testing was routinely offered during the first prenatal visit. HIVST was commonly offered to women who had been diagnosed with an STI for their partner’s use (27/29 observations). In the general health centre, two parallel pathways coexisted: before the consultation, a risk assessment tool was used to offer HIV testing to eligible patients and, after the consultation, patients who had been diagnosed with an STI were referred to a care assistant for HIVST. Due to this HIV testing patient flow, few offers of HIV testing and HIVST were made in this setting (3/16). At the dedicated STI clinic, an HIVST video was played in the waiting room. According to the health professionals interviewed, this video helped reduce the time required to offer HIVST after the consultation. Task-shifting was implemented there: patients were referred to a nurse for HIV testing, and HIVST was commonly offered to STI patients for their partners’ use (28/53). When an HIVST was offered, it was generally accepted (54/58). Both health professionals and patients perceived HIVST positively despite experiencing a few difficulties with respect to offering HIVST to partners and structural barriers associated with the organisation of services. Conclusion The organisation of patient flow and task-shifting influenced HIV testing and offers of HIVST kits. Proposing HIVST is more systematic when HIV testing is routinely offered to all patients. Successful integration requires improving the organisation of services, including task-shifting.

Background: Key populations (KPs), including female sex workers (FSWs), gay men and other men who have sex with men (MSM), people who inject drugs (PWID), and transgender women (TGW) experience disproportionate risks of HIV acquisition. The UNAIDS Global AIDS 2022 Update reported that one-quarter of all new HIV infections occurred among their non-KP sexual partners. However, this fraction relied on heuristics regarding the ratio of new infections that KPs transmitted to their non-KP partners to the new infections acquired among KPs (herein referred to as “ infection ratios” ). We recalculated these ratios using dynamic transmission models. Setting: One hundred seventy-eight settings (106 countries). Methods: Infection ratios for FSW, MSM, PWID, TGW, and clients of FSW were estimated from 12 models for 2020. Results: Median model estimates of infection ratios were 0.7 (interquartile range: 0.5–1.0; n = 172 estimates) and 1.2 (0.8–1.8; n = 127) for acquisitions from FSW clients and transmissions from FSW to all their non-KP partners, respectively, which were comparable with the previous UNAIDS assumptions (0.2–1.5 across regions). Model estimates for female partners of MSM were 0.5 (0.2–0.8; n = 20) and 0.3 (0.2–0.4; n = 10) for partners of PWID across settings in Eastern and Southern Africa, lower than the corresponding UNAIDS assumptions (0.9 and 0.8, respectively). The few available model estimates for TGW were higher [5.1 (1.2–7.0; n = 8)] than the UNAIDS assumptions (0.1–0.3). Model estimates for non-FSW partners of FSW clients in Western and Central Africa were high (1.7; 1.0–2.3; n = 29). Conclusions: Ratios of new infections among non-KP partners relative to KP were high, confirming the importance of better addressing prevention and treatment needs among KP as central to reducing overall HIV incidence.

A bstract HIV self-testing (HIVST) empowers individuals to decide when and where to test and with whom to share their results. From 2019 to 2022, the ATLAS program distributed ∼ 400 000 HIVST kits in Côte d’Ivoire, Mali, and Senegal. It prioritised key populations, including female sex workers and men who have sex with men, and encouraged secondary distribution of HIVST to their partners, peers and clients. To preserve the confidential nature of HIVST, use of kits and their results were not systematically tracked. Instead, an anonymous phone survey was carried out in two phases during 2021 to estimate HIVST positivity rates (phase 1) and linkage to confirmatory testing (phase 2). Initially, participants were recruited via leaflets from March to June and completed a sociobehavioural questionnaire. In the second phase (September-October), participants who had reported two lines or who reported a reactive result were recontacted to complete another questionnaire. Of the 2 615 initial participants, 89.7% reported a consistent response between the number of lines on the HIVST and their interpretation of the result (i.e., ‘non-reactive’ for 1 line, ‘reactive’ for 2 lines). Overall positivity rate based on self-interpreted HIVST results was 2.5% considering complete responses, and could have ranged from 2.4% to 9.1% depending on the interpretation of incomplete responses. Using the reported number of lines, this rate was estimated at 4.5% (ranging from 4.4% to 7.2%). Positivity rates were significantly lower only among respondents with higher education. No significant difference was observed by age, key population profile, country or history of HIV testing. The second phase saw 78 out of 126 eligible participants complete the questionnaire. Of the 27 who reported a consistent reactive response in the first phase, 15 (56%, 95%CI: 36 to 74%) underwent confirmatory HIV testing, with 12 (80%) confirmed as HIV-positive, all of whom began antiretroviral treatment. The confirmation rate of HIVST results was fast, with 53% doing so within a week and 91% within three months of self-testing. Two-thirds (65%) went to a general public facility, and one-third to a facility dedicated to key populations. The ATLAS HIVST distribution strategy reached people living with HIV in West Africa. Linkage to confirmatory testing following a reactive HIVST remained relatively low in these first years of HIVST implementation. However, if confirmed HIV-positive, almost all initiated treatment. HIVST constitutes a relevant complementary tool to existing screening services.

Background: The distribution of new HIV infections among key populations, including female sex workers (FSWs), gay men and other men who have sex with men (MSM), and people who inject drugs (PWID) are essential information to guide an HIV response, but data are limited in sub-Saharan Africa (SSA). We analyzed empirically derived and mathematical model-based estimates of HIV incidence among key populations and compared with the Joint United Nations Programme on HIV/AIDS (UNAIDS) estimates. Methods: We estimated HIV incidence among FSW and MSM in SSA by combining meta-analyses of empirical key population HIV incidence relative to the total population incidence with key population size estimates (KPSE) and HIV prevalence. Dynamic HIV transmission model estimates of HIV incidence and percentage of new infections among key populations were extracted from 94 country applications of 9 mathematical models. We compared these with UNAIDS-reported distribution of new infections, implied key population HIV incidence and incidence-to-prevalence ratios. Results: Across SSA, empirical FSW HIV incidence was 8.6-fold (95% confidence interval: 5.7 to 12.9) higher than total population female 15–39 year incidence, and MSM HIV incidence was 41.8-fold (95% confidence interval: 21.9 to 79.6) male 15–29 year incidence. Combined with KPSE, these implied 12% of new HIV infections in 2021 were among FSW and MSM (5% and 7% respectively). In sensitivity analysis varying KPSE proportions within 95% uncertainty range, the proportion of new infections among FSW and MSM was between 9% and 19%. Insufficient data were available to estimate PWID incidence rate ratios. Across 94 models, median proportion of new infections among FSW, MSM, and PWID was 6.4% (interquartile range 3.2%–11.7%), both much lower than the 25% reported by UNAIDS. Conclusion: Empirically derived and model-based estimates of HIV incidence confirm dramatically higher HIV risk among key populations in SSA. Estimated proportions of new infections among key populations in 2021 were sensitive to population size assumptions and were substantially lower than estimates reported by UNAIDS.

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 populations and non-key populations, 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 people with HIV (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 due to 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 populations (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 populations = 15%), 46% in Mali (male key populations = 23%), and 69% in Senegal (male key populations = 55%). If HIV testing and ART initiation rates remain at current levels, 20% of new HIV infections could be due to undiagnosed key populations living with HIV 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 populations. Addressing these gaps is key to impacting the HIV epidemics in the region and achieving the goal of ending AIDS by 2030.

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.

BACKGROUND:Previously, The Joint United Nations Programme on HIV/AIDS estimated proportions of adult new HIV infections among key populations (KPs) in the last calendar year, globally and in 8 regions. We refined and updated these, for 2010 and 2022, using country-level trend models informed by national data. METHODS:Infections among 15-49 year olds were estimated for sex workers (SWs), male clients of female SW, men who have sex with men (MSM), people who inject drugs (PWID), transgender women (TGW), and non-KP sex partners of these groups. Transmission models used were Goals (71 countries), AIDS Epidemic Model (13 Asian countries), Optima (9 European and Central Asian countries), and Thembisa (South Africa). Statistical Estimation and Projection Package fits were used for 15 countries. For 40 countries, new infections in 1 or more KPs were approximated from first-time diagnoses by the mode of transmission. Infection proportions among nonclient partners came from Goals, Optima, AIDS Epidemic Model, and Thembisa. For remaining countries and groups not represented in models, median proportions by KP were extrapolated from countries modeled within the same region. RESULTS:Across 172 countries, estimated proportions of new adult infections in 2010 and 2022 were both 7.7% for SW, 11% and 20% for MSM, 0.72% and 1.1% for TGW, 6.8% and 8.0% for PWID, 12% and 10% for clients, and 5.3% and 8.2% for nonclient partners. In sub-Saharan Africa, proportions of new HIV infections decreased among SW, clients, and non-KP partners but increased for PWID; elsewhere these groups' 2010-to-2022 differences were opposite. For MSM and TGW, the proportions increased across all regions. CONCLUSIONS:KPs continue to have disproportionately high HIV incidence.

ABSTRACT Introduction HIV self‐testing (HIVST) is a promising strategy to improve diagnosis coverage among key populations (KP). The ATLAS (Auto Test VIH, Libre d'Accéder à la connaissance de son Statut) programme implemented HIVST in three West African countries, distributing over 380,000 kits up between 2019 and 2021, focussing on community‐led distribution by KP to their peers and subsequent secondary distribution to their partners and clients. We aim to evaluate the cost‐effectiveness of community‐led HIVST in Côte d'Ivoire, Mali and Senegal. Methods An HIV transmission dynamics model was adapted and calibrated to country‐specific epidemiological data and used to predict the impact of HIVST. We considered the distribution of HIVST among two KP—female sex workers (FSW), and men who have sex with men (MSM)—and their sexual partners and clients. We compared the cost‐effectiveness of two scenarios against a counterfactual without HIVST over a 20‐year horizon (2019–2039). The ATLAS‐only scenario mimicked the 2‐year implemented ATLAS programme, whereas the ATLAS‐scale‐up scenario achieved 95% coverage of HIVST distribution among FSW and MSM by 2025 onwards. The primary outcome is the number of disability‐adjusted life‐years (DALY) averted. Scenarios were compared using incremental cost‐effectiveness ratios (ICERs). Costing was performed using a healthcare provider's perspective. Costs were discounted at 4%, converted to $USD 2022 and estimated using a cost‐function to accommodate economies of scale. Results The ATLAS‐only scenario was highly cost‐effective over 20 years, even at low willingness‐to‐pay thresholds. The median ICERs were $126 ($88–$210) per DALY averted in Côte d'Ivoire, $92 ($88–$210) in Mali and 27$ ($88–$210) in Senegal. Scaling‐up the ATLAS programme would also be cost‐effective, and substantial epidemiological impacts would be achieved. The ICERs for the scale‐up scenario were $199 ($122–$338) per DALY averted in Côte d'Ivoire, $224 ($118–$415) in Mali and $61 ($18–$128) in Senegal. Conclusions Both the implemented and the potential scale‐up of community‐led HIVST programmes in West Africa, where KP are important to overall transmission dynamics, have the potential to be highly cost‐effective, as compared to a scenario without HIVST. These findings support the scale‐up of community‐led HIVST to reach populations that otherwise may not access conventional testing services.

Background Coverage of HIV testing remains sub-optimal in West Africa. Between 2019 and 2022, the ATLAS program distributed ~400 000 oral HIV self-tests (HIVST) in Côte d’Ivoire, Mali, and Senegal, prioritising female sex workers (FSW) and men having sex with men (MSM), and relying on secondary redistribution of HIVST to partners, peers and clients to reach individuals not tested through conventional testing. This study assesses the proportion of first-time testers among HIVST users and the associated factors. Methods A phone-based survey was implemented among HIVST users recruited using dedicated leaflets inviting them to anonymously call a free phone number. We collected socio-demographics, sexual behaviours, HIV testing history, HIVST use, and satisfaction with HIVST. We reported the proportion of first-time testers and computed associated factors using logistic regression. Results Between March and June 2021, 2 615 participants were recruited for 50 940 distributed HIVST (participation rate: 5.1%). Among participants, 30% received their HIVST kit through secondary distribution (from a friend, sexual partner, family member, or colleague). The proportion who had never tested for HIV before HIVST (first-time testers) was 41%. The main factors associated with being a first-time tester were sex, age group, education level, condom use, and secondary distribution. A higher proportion was observed among those aged 24 years or less (55% vs 32% for 25–34, aOR: 0.37 [95%CI: 0.30–0.44], and 26% for 35 years or more, aOR: 0.28 [0.21–0.37]); those less educated (48% for none/primary education vs 45% for secondary education, aOR: 0.60 [0.47–0.77], and 29% for higher education, aOR: 0.33 [0.25–0.44]). A lower proportion was observed among women (37% vs 43%, aOR: 0.49 [0.40–0.60]); those reporting always using a condom over the last year (36% vs 51% for those reporting never using them, aOR: 2.02 [1.59–2.56]); and those who received their HISVST kit through primary distribution (39% vs 46% for secondary distribution, aOR: 1.32 [1.08–1.60]). Conclusion ATLAS HIVST strategy, including secondary distribution, successfully reached a significant proportion of first-time testers. HIVST has the potential to reach underserved populations and contribute to the expansion of HIV testing services in West Africa.

Background A third of people living with HIV (PLHIV) in Western Africa had an undiagnosed infection in 2020. In 2019-2021, the ATLAS programme has distributed a total of 380 000 HIV self-testing (HIVST) kits to key populations (KP) including female sex workers (FSW) and men who have sex with men (MSM), and their partners in Côte d’Ivoire, Mali and Senegal. We predicted the potential impact of ATLAS and of national HIVST scale-up strategies among KP. Methods A deterministic model of HIV transmission was calibrated to country-specific empirical HIV and intervention data over time. We simulated scenarios reflecting 1) the actual ATLAS HIVST distribution only over 2019-2021 (∼2% of all tests done in countries), and 2) ATLAS followed by a scale-up of HIVST distribution to KP (total of ∼570 000 kits distributed each year). Impacts on HIV diagnosis, new HIV infections and deaths were derived using counterfactual scenarios without HIVST. Findings ATLAS was predicted to substantially increase HIV diagnosis among KP by the end of 2021, especially among MSM in Mali (9·3 percentage point [pp] increase), and a 1·0pp increase overall. ATLAS might have averted a median of 706 new HIV infections among KP over 2019-2028 in the 3 countries combined, especially among MSM, and 1794 new HIV infections (0·4-3·3% of all new HIV infections across countries) and 591 HIV-related deaths overall. HIVST scale-up increased HIV diagnosis at the end of 2028 by around 8pp among FSW and 33pp among MSM in every country. Overall increases ranged from 1·0pp (Côte d’Ivoire) to 11·0pp (Senegal). HIVST scale-up may avert 3-5% of new HIV infections among FSW, 3-10% among FSW clients, and 20-28% among MSM across countries (and 2-16% overall), and avert 13-18% of HIV-related deaths among MSM over 2019-2028. Interpretation Scaling-up HIVST distribution among KP in Western Africa may substantially attenuate disparities in access to HIV testing and help reduce HIV infections and deaths among KP and their partners. Funding Unitaid MRC ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by Unitaid (Grant Number: 2018-23 ATLAS) through a collaborative agreement with Solthis. RS and MCB acknowledge funding from the MRC Centre for Global Infectious Disease Analysis (reference MR/R015600/1), jointly funded by the UK Medical Research Council (MRC) and the UK Foreign, Commonwealth & Development Office (FCDO), under the MRC/FCDO Concordat agreement and is also part of the EDCTP2 programme supported by the European Union. PV, MCB and MMG acknowledge funding from the Wellcome Trust (WT 226619/Z/22/Z). MMG research program is supported Tier 2 Canada Research Chairs. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) license to any Author Accepted Manuscript version arising. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. 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, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors

Introduction Treatment as prevention (TasP) and pre-exposure prophylaxis (PrEP) could impact the HIV epidemic among Female Sex Workers (FSW) but their cost-effectiveness is uncertain in this group. This study aims to model the cost-effectiveness of TasP and PrEP among FSW in Cotonou, Benin. Methods A demonstration study assessed TasP and PrEP use among FSW in Cotonou. A dynamic HIV transmission model was developed to estimate the impact of this intervention and published elsewhere. Incremental economic costs of the study were collected prospectively capturing both provider and FSW costs. The incremental cost-effectiveness ratio per HIV infection and disability-adjusted life years (DALY) averted were estimated over a 20 year time horizon with costs converted to USD 2020 and both costs and DALYs discounted at 4.5% per year. Different cost scenarios were modelled to investigate the cost-effectiveness of the intervention as delivered by the government reflecting current day implementation and resource costs. Results The mean provider annual economic cost per FSW on TasP was $646, with an initiation cost of $347 and mean annual user costs were $16. The mean initiation costs for PrEP were $268, mean annual provider costs were $359-$499 and annual user cost $15-$21 depending on adherence level. TasP was found to be cost saving for all cost scenarios examined compared to routine HIV care for FSW. PrEP was not cost-effective for any cost scenario, population coverage or adherence level examined. Conclusion Our results support TasP but not PrEP for FSW in our setting. A streamlined, outreach delivery model with reduced costs should be investigated to assess its cost-effectiveness in this setting. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Funded by the Bill and Melinda Gates Foundation (Grant no. OPP1098973). Complementary funding was provided by the Canadian Institutes of Health Research (Grant numbers ROH-115205 and FDN-143218). Truvada for pre-exposure prophylaxis was provided free of charge by Gilead Sciences. ### 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: The ethics committee of the CHU de Quebec University Laval, Quebec, Canada, and the Benin National Ethics Committee for Health Research gave ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. 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, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors

The extent to which receptive anal intercourse (RAI) increases the HIV acquisition risk of women compared to receptive vaginal intercourse (RVI) is poorly understood. We evaluated RAI practice over time and its association with HIV incidence during three prospective HIV cohorts of women: RV217, MTN-003 (VOICE), and HVTN 907. At baseline, 16% (RV 217), 18% (VOICE) of women reported RAI in the past 3 months and 27% (HVTN 907) in the past 6 months, with RAI declining during follow-up by around 3-fold. HIV incidence in the three cohorts was positively associated with reporting RAI at baseline, albeit not always significantly. The adjusted hazard rate ratios for potential confounders (aHR) were 1.1 (95% Confidence interval: 0.8–1.5) for VOICE and 3.3 (1.6–6.8) for RV 217, whereas the ratio of cumulative HIV incidence by RAI practice was 1.9 (0.6-6.0) for HVTN 907. For VOICE, the estimated magnitude of association increased slightly when using a time-varying RAI exposure definition (aHR = 1.2; 0.9–1.6), and for women reporting RAI at every follow-up survey (aHR = 2.0 (1.3–3.1)), though not for women reporting higher RAI frequency (> 30% acts being RAI vs. no RAI in the past 3 months; aHR = 0.7 (0.4–1.1)). Findings indicated precise estimation of the RAI/HIV association, following multiple RVI/RAI exposures, is sensitive to RAI exposure definition, which remain imperfectly measured. Information on RAI practices, RAI/RVI frequency, and condom use should be more systematically and precisely recorded and reported in studies looking at sexual behaviors and HIV seroconversions; standardized measures would aid comparability across geographies and over time.