Prioritising place-based strategies for sexually transmitted and blood-borne infection prevention: protocol for the Zingatia Maskan interactive, convergent mixed-methods study in Nairobi, Kenya.

INTRODUCTION

Associations between individual-level 'risk behaviours' and sexually transmitted and blood-borne infection (STBBI) acquisition are well documented; however, increasing evidence highlights the importance of place in shaping ecologies of STBBI risk and safety and access to relevant services. HIV prevention efforts have largely focused on population-based approaches resulting in siloed programming that ignores how sex work locations shape risk and safety for adolescent girls and young women (AGYW), female sex workers (FSW) and men who congregate in these spaces. Marked heterogeneity in STBBI prevalence and reported risk across sex work locations in Nairobi County, Kenya, underscores the need for more nuanced location-based prevention strategies. This paper describes the Zingatia Maskan (ZiMa) study, which aims to examine how physical, organisational, social and relational dimensions of sex work locations in Nairobi County shape ecologies of risk and safety for AGYW, FSW and their male sexual partners.

METHODS AND ANALYSIS: The ZiMa study will employ an interactive, convergent mixed-methods design, implemented across three interlinked phases. Phase 1 will involve programmatic mapping to identify and describe sex work locations and estimate population sizes. Mapping findings will then inform purposive sampling for peer ethnography and key informant interviews that will subsequently explore social and relational dynamics within locations. Phase 2 will comprise a cross-sectional biobehavioural survey to assess STBBI outcomes, contextual determinants and related programme coverage. In phase 3, findings will be integrated iteratively across phases, with ongoing community engagement, through the ZiMa Community Advisory Board, informing refinement of data collection and interpretation.

ETHICS AND DISSEMINATION: This study has received ethical approval from the Amref Ethics and Scientific Review Committee (Kenya) and the Committee for Harmonized Health Impact, Privacy, and Ethics Review (Manitoba, Canada). Study findings will be shared with community members, programme teams and study co-investigators through structured in-person meetings in Nairobi to support collaborative validation and interpretation of results and inform actionable programme refinements, and with national and subnational Technical Working Groups to inform policies. For academic audiences, findings will be presented at international conferences, meetings and workshops and published in open-access, peer-reviewed journals.