ONE HEALTH FOR ANTIMICROBIAL RESISTANCE: A SYSTEMATIC REVIEW AND META-ANALYSIS (2019-2026)

Background: Antimicrobial resistance (AMR) constitutes one of the most pressing global public health threats, with an estimated 4.95 million deaths associated with resistant infections in 2019. The One Health framework, recognizing the interconnectedness of human, animal, and environmental health, has emerged as the paradigmatic approach to understanding and combating AMR. This systematic review synthesizes evidence from 2019 to 2026 on AMR across the human-animal-environment interface. Methods: Following PRISMA 2020 guidelines, we systematically searched PubMed, Scopus, Web of Science, Embase, and Google Scholar for peer-reviewed studies published between January 2019 and June 2026. Eligible studies addressed AMR or antimicrobial resistance genes (ARGs) across at least two One Health domains. Primary outcomes included AMR prevalence, ARG distribution, and transmission pathways. Risk of bias was assessed using the Joanna Briggs Institute (JBI) checklists. Random-effects meta-analyses were performed where appropriate, with heterogeneity assessed using I² statistics. Results: Of 2,847 identified records, 127 studies met the inclusion criteria. The included studies encompassed data from 47 countries across six WHO regions. Escherichia coli was the most frequently reported organism across all domains. Pooled resistance rates showed high prevalence to Access group antibiotics (ampicillin: 52%, 95% CI: 47-57%; tetracycline: 49%, 95% CI: 44-54%) and Watch group antibiotics (ciprofloxacin: 41%, 95% CI: 36-46%). Reserve antibiotic resistance, while lower (colistin: 14%, 95% CI: 9-20%; carbapenems: 12%, 95% CI: 7-18%), showed concerning temporal increases. Poultry and wastewater were identified as major resistance reservoirs. Significant geographical disparities exist, with the highest resistance rates observed in low- and middle-income countries. Only 23% of studies included all three One Health domains simultaneously, and socioeconomic impact assessments showed near-exclusive focus on human health (98.2% of data sources). Conclusions: This review demonstrates that AMR is a truly multisectoral challenge requiring coordinated surveillance across all One Health domains. Critical evidence gaps persist regarding environmental transmission pathways, socioeconomic impacts across sectors, and integrated intervention effectiveness. Strengthening national One Health surveillance systems incorporating WHO AWaRe and Critically Important Antimicrobial frameworks is urgently needed.