Mapping antimicrobial resistance interventions in ASEAN countries: a scoping review of implementation patterns, One Health integration, and evidence gaps

INTRODUCTION: Antimicrobial resistance (AMR) is a critical and escalating public health threat globally, with Southeast Asia facing particularly high burdens due to elevated antimicrobial consumption, fragmented health systems, and uneven regulatory enforcement. Although member states of the Association of Southeast Asian Nations (ASEAN) have introduced AMR-related initiatives aligned with the Global Action Plan on AMR, the regional evidence base remains dispersed, fragmented across sectors, and insufficiently synthesized from a One Health perspective. This scoping review aimed to systematically map implemented AMR interventions across ASEAN countries, characterize their implementation patterns, assess the extent of One Health integration, and identify evidence gaps. METHODS: We conducted a scoping review following PRISMA-ScR guidelines. PubMed/MEDLINE, Scopus, and ScienceDirect were searched for empirical studies published between January 1, 2018, and December 31, 2025, that reported the implementation of AMR-related programs, policies, or interventions in ASEAN member states. Data on country, sector, setting, intervention type, One Health pillar, study design, and outcomes were extracted and analyzed using narrative synthesis. RESULTS: Of 9,832 records screened, 57 studies met the inclusion criteria. Evidence was heavily concentrated in three countries: Thailand (n = 15, 26.3%), Singapore (n = 13, 22.8%), and Vietnam (n = 12, 21.1%), accounting for 70.2% of all studies. Critically, no eligible peer-reviewed studies were identified from Brunei Darussalam, while Laos and Cambodia were represented only through disaggregated data from one multi-country surveillance study. The human health sector dominated (86.0%), while only 8.8% of studies adopted integrated One Health approaches, and no studies addressed the environmental sector in isolation. Antimicrobial stewardship was the most common intervention (63.2% of studies), but explicit use of implementation science frameworks was rare. Fifteen studies (26.3%) evaluated multi-component interventions, indicating an emerging shift toward integrated strategies. Most studies employed observational designs (50.9%) and assessed short-term process outcomes rather than sustained resistance reduction. CONCLUSIONS: This comprehensive mapping of AMR interventions across all ten ASEAN countries reveals extreme geographical and sectoral inequities. The complete absence of evidence from three member states and the dominance of hospital-based human health interventions underscore the urgent need for targeted investment in underrepresented settings and genuinely integrated One Health approaches. Without such advances, antimicrobial resistance initiatives in ASEAN will remain fragmented and unable to achieve sustained population-level impact.