Antimicrobial resistance beyond hospitals: wastewater as a critical blind spot in AMR surveillance and control in low-income countries: a narrative review

ABSTRACT

-Antimicrobial resistance (AMR) is a growing global health threat that extends beyond clinical settings and increasingly involves environmental reservoirs. Wastewater represents a critical yet often overlooked component of AMR surveillance and control, particularly in low-income countries where sanitation infrastructure and environmental monitoring remain limited. This review adopted a narrative approach because of heterogeneity in study designs, environmental matrices, detection methodologies, and policy-oriented and institutional evidence not amenable to quantitative meta-analysis. Literature was retrieved from PubMed, MEDLINE, Scopus and ScienceDirect for studies published between 2016 and 2025. Evidence indicates that untreated or inadequately treated wastewater receives resistant microorganisms and antibiotic residues from households, healthcare facilities, agriculture, and industrial activities, creating environmental hotspots that facilitate horizontal gene transfer and resistome enrichment. Wastewater-based surveillance offers a cost-effective, population-level tool for monitoring AMR trends and complementing existing surveillance systems, including the WHO Global Antimicrobial Resistance and Use Surveillance System (GLASS). Major challenges include methodological heterogeneity, grab versus composite sampling biases, laboratory limitations, inadequate wastewater treatment infrastructure, and insufficient integration of environmental surveillance into national AMR action plans. Strengthening wastewater surveillance within a One Health framework, improving wastewater management, and standardizing monitoring approaches are essential to reduce AMR dissemination and protect public health.