Representation of urban and rural contexts in the application of wastewater surveillance for antimicrobial resistance: A systematic review.

Wastewater surveillance (WWS) can reveal community health trends through targeted monitoring of sewage. Given concerns regarding the global dissemination of drug-resistant infections, there is growing integration of antimicrobial resistance (AMR) in WWS infrastructure. However, most WWS has focused on highly urbanized sewersheds in resource-rich areas, which may exacerbate disparities in disease burdens and clinical datasets. This work presents both a systematic and scoping review of current published WWS efforts targeting antimicrobial resistance (AMR), with the aim to quantify and compare applied monitoring efforts capturing rural vs. urban areas and lower-income vs. higher-income countries. Of the 2,873 deduplicated manuscripts identified through a systematic search of four databases, 454 examined untreated domestic sewage and were characterized via a brief scoping review. Of these, 48 articles included an explicit focus on monitoring for population health surveillance, and were subject to methodological data extraction and risk of bias assessment. Sampling trends observed in the scoping and systematic review were similar. Only 13-19 % of scoping review sampling sites were classified as rural, and 44 % were located within lower- or middle-income countries (LMICs). Few articles examined AMR within unsewered communities. While analytical methods were similar across income brackets, rural monitoring efforts were more reliant on culture-based techniques than urban efforts. Monitoring in rural sites and LMICs were typically part of multi-site campaigns and featured less longitudinal sampling. Overall, methodological inconsistencies rendered a meta-analysis infeasible. The combined lack of research in rural and low-income areas indicates that key at-risk communities for circulation of AMR are an oversight.