Strengthening the HIV prevention cascade to maximise epidemiological impact in Eastern Zimbabwe: a modelling study
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Published version
Author(s)
Type
Journal Article
Abstract
Background HIV prevention cascades provide a systematic understanding of barriers to prevention. In this study we use mathematical modelling to understand the consequences of these barriers and how the cascade could be strengthened to maximise epidemiological impact, providing potentially important insights for programmes. Methods We use an individual-based model of HIV transmission (PopART-IBM), calibrated to cohort data from eastern Zimbabwe. HIV prevention cascade estimates from this cohort are used as probabilities for indicators in the model representing an individual’s ‘motivation’, ‘access’ and ‘capacity to use effectively’ pre-exposure prophylaxis, voluntary male medical circumcision and condom use. We examine how current barriers affect the number and distribution of HIV infections compared to a no-barrier scenario. Using assumptions about how interventions could strengthen the HIV prevention cascade, we estimate the reduction in HIV infections over a ten-year period through addressing different elements of the cascade. Findings 22,000 new potentially ‘avertable’ HIV infections will occur over the next ten years due to existing HIV prevention cascade barriers, 74·2% of the 28,000 new infections that would occur with existing barriers in a population of approximately 1·2 million adults. Removing these barriers would reduce HIV incidence below the benchmarks for epidemic elimination. Addressing all cascade steps in one priority population is much more impactful than addressing one step across all populations. Interpretation Interventions exists in eastern Zimbabwe to reduce HIV towards elimination, but barriers of motivation, access and effective use prevent their full effect being realised. Interventions need to be multi-layered, and address all steps along the HIV prevention cascade. Models incorporating the HIV prevention cascade can help identify the main barriers to greater impact. Funding National Institutes of Mental Health, Bill and Melinda Gates Foundation, and Medical Research Council Centre for Global Infectious Disease Analysis funding from the UK Medical Research Council and Department for International Development.
Date Issued
2023-07-01
Date Acceptance
2023-04-20
ISSN
2214-109X
Publisher
Elsevier
Start Page
e1105
End Page
e1113
Journal / Book Title
The Lancet Global Health
Volume
11
Issue
7
Copyright Statement
© 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license (https://creativecommons.org/licenses/by/4.0/)
Publication Status
Published