<b>Pre-exposure Prophylaxis (PrEP) implementation among People Who Inject Drugs (PWID) in Sub-Saharan Africa: A scoping review of Implementation determinants (barriers and facilitators) and Implementation strategy.</b>

Background: Sub-Saharan Africa (SSA) has suffered the greatest impact of the global HIV pandemic. Given the rapid increase in risky injection drug use in SSA, the HIV crisis is intensifying among people who inject drugs (PWID). This population is 35 times more likely to acquire HIV, yet utilization of HIV pre-exposure prophylaxis (PrEP) remains strikingly low (0-3%). Unique high-risk practices in this region such as "bluetoothing", a practice in which blood is withdrawn from one individual who has recently injected a drug and directly injected intravenously into another person combined with hostile legal environment and social stigma that drive PWID away from healthcare, creates an urgent need for locally designed implementation strategies to address specific determinants of PrEP uptake among PWID in SSA.Objectives: This scoping review aims to: (1) identify the major barriers and facilitators determining implementation of PrEP among PWID in SSA; (2) identify the implementation strategies employed to increase PrEP utilization; and (3) identify gaps in existing literature and opportunities to improve implementation outcomes.Methods: We will conduct this scoping review following the Joanna Briggs Institute manual and report findings using PRISMA-ScR guidelines. We will systematically search databases including PubMed, EMBASE, Scopus, Web of Science, and Global Health, alongside grey literature, including relevant literature from 2016 onwards, since PrEP implementation in SSA started in 2016. Two independent reviewers will screen studies and extract data using a tool pilot-tested by the research team, any discrepancies between the two reviewers will be resolved by a third reviewer who is a senior researcher. Implementation determinants will be mapped according to the Consolidated Framework for Implementation Research (CFIR), and strategies will be categorized using the Expert Recommendations for Implementing Change (ERIC) taxonomy.Conclusion: Findings will support policymakers, healthcare providers, and researchers in understanding barriers and gaps in PrEP implementation. This evidence will guide the development and scale-up of interventions and policies to address the low uptake and reach of PrEP services to PWID in Sub-Saharan Africa.