IMPERATIVE: Harnessing male peer networks to enhance engagement with HIV prevention: A large-scale cluster randomised trial to increase HIV self-testing and PrEP uptake among men in Eastern Zimbabwe

Background Engaging men in HIV prevention remains a critical challenge in sub-Saharan Africa. While HIV self-testing (HIVST) and pre-exposure prophylaxis (PrEP) are efficacious prevention methods, uptake among men remains low. Peer network distribution of HIVST has shown promise, but no large-scale studies have evaluated its impact on PrEP uptake combined with mobile phone support, especially among men. This protocol describes a cluster randomised controlled trial evaluating a multi-component intervention to increase HIVST use and PrEP uptake among men through peer network distribution with enhanced risk perception counselling and telephone support. Methods/Design: This trial will be implemented in 44 clusters across eight sites in Manicaland Province, Eastern Zimbabwe. Eligible men aged 18 and above will be recruited through peer network distribution initiated by primary distributors. The intervention includes: (1) HIVST kit distribution through male peer networks, (2) toll-free helpline for pre- and post-test support, (3) SMS-based self-administered HIV risk assessment, and (4) facilitated linkage to confirmatory testing and PrEP at local clinics, including incentivisation and compensation. The primary outcome is the proportion of men initiating PrEP. Secondary outcomes include ART initiation, clinic-based HIV testing rates, and PrEP retention at one-month follow-up. The study is powered to detect an increase from 2% to 8.5% in PrEP initiation. A comprehensive process evaluation will assess implementation fidelity and network characteristics affecting outcomes. Mathematical modelling will project population-level impact and cost-effectiveness. Discussion This will be the first large-scale randomised trial to evaluate whether peer network-based HIVST distribution combined with mobile health support and improved risk perception increases PrEP uptake among men in a high HIV-burden setting. If successful, this scalable intervention could inform national HIV prevention programmes across sub-Saharan Africa seeking to improve male engagement with prevention services. Trial registration: ClinicalTrials.gov NCT06370923. Registered on 12-Apr-2024.