One health strategies for zoonosis prevention in developing countries: A systematic review (2015–2025)

Background: Despite growing global investment in One Health initiatives, limited systematic synthesis exists examining veterinary authority strategies and their performance outcomes in developing countries, creating a knowledge gap for evidence-based policy formulation. Objective: To develop a comprehensive taxonomy of One Health zoonosis prevention strategies implemented by veterinary authorities in developing countries and establish quantitative effectiveness patterns across resource-constrained settings. Methods: We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, searching Scopus, Web of Science, and PubMed for peer-reviewed studies published between January 2015 and July 2025. Two reviewers independently screened 126 records after deduplication with inter-rater agreement (κ = 0.82). We employed mixed-methods synthesis integrating thematic analysis and quantitative effectiveness scoring across 42 included studies. Results: From 42 studies spanning 18 countries, we identified 14 distinct One Health strategies organized into three dominant modalities: intersectoral coordination mechanisms (35.7%), surveillance system enhancement (28.6%), and integrated service delivery (21.4%). Integrated approaches consistently demonstrated superior effectiveness scores (77–90, 95% CI: 73–94) compared to single-intervention strategies (25–95, 95% CI: 18–88). Mobile surveillance systems achieved 14-fold reporting increases (RR = 14.0, 95% CI: 13.8–14.2), while integrated surveillance systems demonstrated improved epidemiological understanding across human-animal interfaces. Conclusions: Implementation quality and strategic integration represent more critical determinants of success than intervention type or resource intensity alone. Sub-optimal policy implementation and poor inter-sectoral coordination were consistently identified as barriers to achieving desired outcomes. These findings provide evidence-based guidance for optimizing limited resources in developing countries.