CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

1129 IMPACT OF COMBINATION HIV PREVENTION IN ZIMBABWE: A MULTIDISTRICT TRANSMISSION MODEL

Jan A. Hontelez 1 , Isaac Taramusi 2 , Gerald Shambira 3 , Roel Bakker 1 , Caroline Bulstra 1 , Frances Cowan 4 , Godfrey Matsinde 5 , Suzette M.Matthijsse 1 , Cai M. Rui 1 , Richard Steen 1 , Mutsa Mhangara 6 , Amon Mpofu 2 , Sake de Vlas 1 1 Erasmus University Medical Center, Rotterdam, Netherlands, 2 National AIDS Council of Zimbabwe, Harare, Zimbabwe, 3 University of Zimbabwe, Harare, Zimbabwe, 4 Centre for Sexual Health & HIV/AIDS Research, Harare, Zimbabwe, 5 Zimbabwe National Statistics, Harare, Zimbabwe, 6 Zimbabwe Ministry of Health and Child Care, Harare, Zimbabwe Background: The Zimbabwean HIV epidemic is generalized, and heterogeneous at the district level. Combination HIV prevention (CHP) has been rolled out in Zimbabwe over the past decades, including antiretroviral therapy (ART), voluntary male medical circumcision (VMMC), prevention of mother to child transmission, behavior change programmes, and condom distribution. Evaluating the impact of these programs on the HIV epidemic is important to improve intervention planning. Methods: Together with local policy makers and stakeholders, we developed a multidistrict, individual based HIV transmission model that simulates dynamic interactions between districts to accurately represent transmission dynamics, and quantified it using Zimbabwean demographic, epidemiological, and behavioral data. We used this model to evaluate the impact and cost- effectiveness of CHP in Zimbabwe over the period 2011 – 2015. This period was chosen as it encapsulates the national HIV strategic plan, and because the two large-scale population based surveys were conducted at the end of that period. We also estimate the future impact of alternative strategies. Results: We simulated the Zimbabwean HIV epidemic over 4 different districts, representative of rural, urban, mining, and commercial farming districts, and were able to reproduce district specific and national census data, sexual behavior in key and general populations, and HIV prevalence and incidence. We show that CHP in Zimbabwe over the period 2011 – 2015 prevented an estimated total of 90 thousand new infections, at 2259 US$ per infection averted (table). Interventions were most cost-effective in urban districts, and least cost-effective in rural districts. Importantly, our model closely reproduced national HIV incidence estimates in 2015 without specifically tuning to these data, serving as an important validation of our unique approach, and shows that we managed to closely reproduce the effects of CHP on incidence. Conclusion: We have shown that CHP in 2011-2015 in Zimbabwe was highly cost-effective, even over the short period of implementation. Our approach in modeling a geospatially dynamic representation of the Zimbabwean HIV epidemic proved successful, and could be a valuable to further understand underlying transmission dynamics, and in turn optimize location specific resource allocation, allowing for the dynamic spillover effects of these interventions to other areas. Further expanding these tools could help policy makers in Zimbabwe and other countries to develop efficient and effective strategies to end AIDS by 2030.

1128 OPTIMIZING HIV PREVENTION EFFORTS WITHOUT NEW INVESTMENT CAN REDUCE INCIDENCE Evin Jacobson 1 , Katherine A.Hicks 2 , Justin Carrico 2 , Stephanie L.Sansom 1 1 CDC, Atlanta, GA, USA, 2 RTI International, Research Triangle Park, NC, USA Background: We optimized current societal spending on HIV prevention to assess how best to achieve large reductions in HIV incidence. Methods: We used a national model of HIV transmission to estimate the potential maximum 10-year reduction in new infections from 2018 to 2027. The model applied current estimated public and private HIV prevention spending ($2.6 billion for 2018) each year to the following intervention categories: HIV screening (high- and low-risk MSM and heterosexuals, PWID), HIV care continuum (linkage to care at and after diagnosis, prescription of ART, retention in care, viral suppression), PrEP, and SSPs. The model optimized expenditures for two consecutive 5-year periods. We compared the base case (no optimization) to two optimization scenarios: a limited-reach scenario, in which estimates of the maximum number of persons who can be reached by each intervention generally reflect current conditions; and an ideal, unlimited-reach scenario, where all eligible persons can be reached by each intervention. Results: In the base case in which 30.0% and 16.7% of societal investments are applied to HIV screening and care-continuum interventions, there were 331,000 new cases over the next 10 years. Optimization in the limited-reach scenario in the first 5 years decreased the allocation to HIV screening to 13.4% and increased the allocation to care-continuum interventions to 35.1%. In the unlimited-reach scenario, allocations to both HIV screening and care- continuum interventions increased (to 35.4% and 64.6%, respectively). The 10-year reduction in incidence was 69% in the limited-reach scenario and 94% in the unlimited-reach scenario. Investment in HIV screening decreased in the limited-reach scenario to focus on groups other than low-risk heterosexuals, whereas in the unlimited-reach scenario, screening investments increased to cover all eligible persons. In the unlimited-reach scenario, investment in PrEP was minimized because that scenario included extensive diagnosis and effective viral suppression through the increased funding of ART adherence interventions. However, under the more realistic conditions of the limited-reach scenario, continued investment in PrEP was required. Conclusion: Optimal allocation of current societal investments in HIV prevention can achieve substantial reductions in new infections. Achieving reductions over 90% is theoretically possible, but implausible with current resources.

Poster Abstracts

CROI 2020 426