Title : Addressing AMR: A scoping review of wastewater treatment measures
Abstract:
Background: Antimicrobial resistance (AMR) is a One Health issue involving humans, animals, and the environment. Without effective treatment, management, and monitoring, wastewater can serve as reservoirs for antimicrobial-resistant bacteria (ARBs), antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and antimicrobial residues. However, evidence on treatment effectiveness across technologies, targets, and settings remains fragmented. This scoping review synthesized international evidence on the effectiveness of wastewater treatments in reducing AMR-related contamination.
Methods: A scoping review was conducted using the Population–Concept–Context framework. The review covered hospital and community wastewater systems and sludge/faecal sludge management. Searches of PubMed, ScienceDirect, TCI, WHO, UNEP, World Bank, and Thai government sources identified 29 eligible studies published between 2016 and 2025. Data were extracted on treatment systems, AMR-related indicators, reported performance, reduction mechanisms, and implementation considerations. Treatment approaches were grouped into conventional and engineered biological systems, nature-based systems, membrane-based technologies, additional treatments including disinfection and advanced oxidation, and hybrid systems.
Results: Most studies assessed ARGs or MGEs (96.6%; n = 28/29), followed by culture-based ARBs (62.1%; n = 18/29), while antimicrobial residues were less frequently assessed (24.1%; n = 7/29). Escherichia coli was the most commonly evaluated bacterial indicator (48.3%; n = 14/29). Treatment effectiveness varied across technologies and target indicators. Conventional and engineered biological systems achieved approximately 1–4 log reduction in ARBs and 0.1–3 log reduction in ARGs, while nature-based systems achieved 0.9–4.8 log and 0.3–4.5 log reduction, respectively. Membrane-based systems showed the strongest physical removal, achieving 2.3–7.5 log reduction in ARBs and up to 7.7 log reduction in selected ARGs. Additional treatments achieved 1.3–4.3 log reduction in ARBs, although ARG reduction was more variable. Hybrid or multiple-barrier systems provided the broadest overall control, with >99.9% ARB reduction or non-detection and 0.55–5.2 log reduction in selected ARGs. A 1-log and 5-log reduction correspond to approximately 90% and 99.999% decreases, respectively, in the measured level of the target indicator.
Conclusion: Wastewater and sludge management are important entry points for AMR prevention and control. High coverage of effective and affordable treatment measures, integrated One Health monitoring, and multiple-barrier approaches are needed to limit environmental release of AMR-related indicators and strengthen surveillance.
