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For more information, visit hptn.org and follow us: Facebook: HIVptn | Twitter: @HIVptn | Youtube: HIVptn U.S. NATIONAL INSTITUTES OF HEALTH: National Institute of Allergy and Infectious Diseases National Institute of Mental Health National Institute of Drug Abuse Female−to−male transmissions Male−to−female transmissions Low Medium High Low Medium High Low Medium High Risk group of recipient 0.00 0.05 0.10 0.15 0.20 0.25 Presented at the 2020 Conference on Retroviruses and Opportunistic Infections (CROI) Boston, Massachusetts, 8-11 March 2020 Poster Number: 1076 HIV-1 Dynamics Following Universal Testing-and-Treatment within HPTN 071 (PopART) William J. M. Probert 1 , Rafael Sauter 1 , Michael Pickles 2 , Anne Cori 2 , Helen Ayles 3 , Peter Bock 4 , Deborah J. Donnell 5 , Sarah Fidler 2 , Richard J. Hayes 6 , Christophe Fraser 1 , for the HPTN 071 (PopART) study team 1 University of Oxford, Oxford, UK, 2 Imperial College London, London, UK, 3 Zambart, Lusaka, Zambia, 4 Desmond Tutu TB Centre, Western Cape, South Africa, 5 Fred Hutchinson Cancer Research Center, Seattle, WA, USA, 6 London School of Hygiene & Tropical Medicine, London, UK FIGURE 2. Predicted incidence (left-hand panels) and predicted probability of transmitting HIV at least once (right-hand panels), over the trial period stratified by sex and sexual risk-taking behaviour. Distribution over 1000 parameter sets from model calibration. RESULTS – PREDICTED PATTERNS DURING THE TRIAL Incidence was predicted to be higher in the high-risk group but differences in the size of these populations meant the largest proportion of transmissions was between those in the medium risk groups (Figs. 1,2,3). The overall probability of onwards transmission was similar between medium- and high-risk groups (Fig. 2). BACKGROUND Universal HIV testing-and-treatment (UTT) has been shown to be effective in high prevalence areas in sub-Saharan Africa (SSA) to reduce HIV incidence. Community-wide interventions may change the contribution of groups with different sexual risk-taking behaviour to ongoing HIV incidence and transmission. Understanding these changes will inform future policy towards achieving zero new infections in the context of UTT. METHODS Using an individual-based model (PopART-IBM), developed as part of the HPTN 071 (PopART) trial, we project the impact of four scenarios of UTT to 2030, stratified by categories of sexual risk-taking behaviour. The model was calibrated to an intervention community in Zambia using trial data. Categories of sexual risk-taking behavior were derived from trial data from surveys of sexual behavior on reported number of lifetime sexual partners and age. Projected scenarios were : 1) Simulation of the PopART trial and continuation of a CHiPs intervention after the trial; 2) Discontinuation of a CHiPs intervention after the trial; 3) Simulation of nationwide CHiPs intervention in communities where the trial did not take place; 4) No simulated trial and no CHiPs intervention (counterfactual). Continuation of a UTT approach to 2030 predicts both a substantial drop in incidence and an epidemic that will become more concentrated in those with the highest levels of sexual risk- taking behaviour. FIGURE 3. Average proportion of total transmissions over trial period (2014.5-2018) between individuals in different groups of sexual risk-taking behavior and stratified by the sex of the source of transmission. Denominator is total number of transmissions over the trial period. ACKNOWLEDGEMENTS HPTN 071 is sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) under Cooperative Agreements UM1-AI068619, UM1-AI068617, and UM1-AI068613, with funding from the U.S. President's Emergency Plan for AIDS Relief (PEPFAR). Additional funding is provided by the International Initiative for Impact Evaluation (3ie) with support from the Bill & Melinda Gates Foundation, as well as by NIAID, the National Institute on Drug Abuse (NIDA) and the National Institute of Mental Health (NIMH), all part of the U.S. National Institutes of Health (NIH). We also wish to acknowledge implementing partners in South Africa (City of Cape Town and Western Cape Government health departments, Kheth’ Impilo, ANOVA Healthcare, SACTWU Worker Health Programme and Supply Chain Management Services) and Zambia (Zambian Ministry of Health, CIDRZ, ZPCT II and JSI). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIAID, NIMH, NIDA, PEPFAR, 3ie, or the Bill & Melinda Gates Foundation. FIGURE 1. HIV prevalence at trial start (mid-2014) (left-hand panel) and proportion of the entire population (14+ years old; right-hand panel) in each subgroup. Distribution is over 1000 parameter sets from model calibration. 0 5 10 15 20 25 0 1 2 3 4 5 0.00 0.25 0.50 0.75 1.00 0.00 0.05 0.10 0.15 0.20 Incidence per 100 person−years Density Low risk Medium risk High risk 0.0 0.2 0.4 0 20 40 60 0 10 20 0 2 4 6 Probability of transmitting HIV over trial period among PLHIV at trial start Female Male HIV acquisition HIV transmission FIGURE 4. Projections of different scenarios of UTT from 2020-2030 stratified by sexual risk-taking behaviour. Shaded area is 95% quantiles of model output. RESULTS - PROJECTIONS TO 2030 Making ART universally accessible to all who are HIV- positive in the PopART community would lead to a substantial decline in incidence in all risk groups but would concentrate new cases in those with the highest levels of risk-taking behaviour (65% of incident cases vs 54% if no UTT was implemented; Fig. 4). While population HIV incidence to 2030 decreases substantially, the model predicts continued persistence of an HIV epidemic in the high-risk subpopulation in all scenarios unless nationwide UTT is adopted. CONCLUSIONS Our results highlight that continuation of a UTT approach to 2030 has the capacity to confer dramatic reductions in new HIV infections. Targeting of high-risk individuals for HIV and STI prevention, testing, and treatment may be necessary following successful UTT interventions in order to eliminate HIV as a public health issue in SSA. RESULTS – CHARACTERISTICS AT TRIAL START At trial start (mid-2014.5) mean HIV prevalence in the risk groups was 6% (low), 22% (medium), and 53% (high). The proportion of the 14+ year old population in each group was 52% (low), 38% (medium) 10% (high). Predicted female-to-male HIV prevalence ratio decreased with increasing risk group (Fig. 1). 0.0 0.1 0.2 0.3 0.0 2.5 5.0 7.5 0.0 2.5 5.0 7.5 0 5 10 15 Proportion of population in subgroup (mid−2014) 0.00 0.25 0.50 0.75 0 5 10 15 20 0 2 4 6 0 1 2 3 4 5 HIV prevalence (mid−2014) Density Low risk Medium risk High risk Female Male PopART/UTT continued (scenario 1) No PopART/No UTT (scenario 4) Prevalence Number of incident cases Proportion of incident cases 2010 2030 2010 2030 0.0 0.4 0.8 0.0 0.4 0.8 0 300 600 Risk group of source
