Climate, One Health Governance, and System Design: AMR Risks in the Western Pacific

Across the Western Pacific, climate-driven stressors are increasingly discussed as a “why now” amplifier of antimicrobial resistance (AMR) and related mortality. This update summarizes a mixed-methods systematic analysis linking temperature and rainfall changes with resistance genes in environmental reservoirs and pathogen-specific AMR-attributable mortality in a Western Pacific climate–AMR analysis. Climate shocks can also disrupt infection control and healthcare delivery, complicating appropriate antibiotic use during and after extreme events.

Warmer, wetter, and more variable conditions can reshape where resistant organisms and resistance genes persist. The result is a higher likelihood of encountering harder-to-treat infections even when local prescribing practices have not abruptly changed. The signals summarized here align with three pathway categories: biological and ecological effects (accelerated microbial growth and selection dynamics, with potential shifts in horizontal gene transfer and gene persistence), environmental infrastructure effects (flooding and contamination that stress water, sanitation, and wastewater systems), and care-delivery effects (crowding, disrupted services, altered empiric therapy, and changes in antibiotic availability that can influence use patterns). At the bedside and in stewardship programs, these dynamics can surface as altered local ecology, higher colonization pressure, and more frequent “brittle” moments when empiric therapy is broadened under uncertainty.

AMR surveillance often becomes visible only once resistance reaches the clinical laboratory, leaving environmental and climate context undermeasured. Gaps implied by this evidence package include fragmented data streams across human health, animal health, and the environment; limited capacity to link AMR signals in near-real time with heat, rainfall, or extreme-event indicators; and uneven laboratory and reporting capability across a region with heterogeneous resources and baseline risk. A pragmatic prioritization ladder follows from these constraints: align datasets, definitions, and reporting standards so clinical and non-clinical signals can be compared; extend sentinel sampling to water, soil, and wastewater where exposure is plausible; and add extreme-weather “triggers” that prompt surge sampling and rapid interpretation during flooding, cyclones, heatwaves, or displacement. Integrated surveillance strengthens earlier detection and supports more targeted interventions by clarifying when clinical clusters may be downstream of environmental and climate disruption.

Planning for AMR control under climate volatility increasingly requires interventions that hold during heatwaves, cyclones, floods, or population displacement—not only during routine operations. Within stewardship, continuity plans can include pre-specified empiric pathways for post-disaster syndromes, decision support that accounts for local susceptibility shifts, and coverage models that persist when staffing patterns change. In infection prevention and control and WASH, priorities include rapid reinforcement of hand hygiene access, water quality assurance, and contingency protocols for environmental cleaning and cohorting when infrastructure is damaged. Supply-chain resilience can be built through stock buffers for priority antimicrobials and diagnostics, alternate distribution routes when transport is interrupted, and cold-chain contingencies when temperature exposure threatens medication integrity. Feasibility improves when stewardship, IPC, and service continuity are designed as one operational package rather than parallel initiatives competing for the same surge resources.

Technical fixes tend to stall when governance is fragmented, particularly when One Health responsibilities span multiple ministries and operational tiers with different incentives. Recurring failure modes include unclear authority for incident response across human, animal, and environmental health agencies; delayed data sharing that prevents early action; misaligned incentives that discourage transparent reporting; procurement vulnerabilities that surface during emergencies; and inconsistent enforcement of antimicrobial policy across sectors that allows selective pressure to persist outside clinical settings. Coordination levers that can be operationalized include formal interagency incident management with pre-agreed thresholds for escalation, joint budgeting for surveillance and response capacity, shared dashboards and data standards to support comparability, routine cross-sector simulation exercises to test decision pathways, and regional data-exchange agreements that reduce cross-border blind spots. Clearer governance shortens time-to-detection and time-to-action during compound climate and outbreak events—the interval in which preventable AMR amplification may be greatest.