Strategic Approach for Prioritising Local and Regional Sanitation Interventions for Reducing Global Antibiotic Resistance

Abstract

Globally increasing antibiotic resistance (AR) will only be reversed through a suite of multidisciplinary actions (One Health), including more prudent antibiotic use and improved sanitation on international scales. Relative to sanitation, advanced technologies exist that reduce AR in waste releases, but such technologies are expensive, and a strategic approach is needed to prioritize more affordable mitigation options, especially for Low- and Middle-Income Countries (LMICs). Such an approach is proposed here, which overlays the incremental cost of different sanitation options and their relative benefit in reducing AR, ultimately suggesting the “next-most-economic” options for different locations. When considering AR gene fate versus intervention costs, reducing open defecation (OD) and increasing decentralized secondary wastewater treatment, with condominial sewers, will probably have the greatest impact on reducing AR, for the least expense. However, the best option for a given country depends on the existing sewerage infrastructure. Using Southeast Asia as a case study and World Bank/WHO/UNICEF data, the approach suggests that Cambodia and East Timor should target reducing OD as a national priority. In contrast, increasing decentralized secondary treatment is well suited to Thailand, Vietnam and rural Malaysia. Our approach provides a science-informed starting point for decision-makers, for prioritising AR mitigation interventions; an approach that will evolve and refine as more data become available.

Complexities in understanding antimicrobial resistance across domesticated animal, human, and environmental systems

“…The extent of suitable waste management options is even less for domesticated animals, which implies that massive quantities of untreated animal fecal matter are entering the environment, potentially contaminating food and water, and also threatening public health. A strong push to address the problem is currently occurring at the World Health Organization (WHO), the World Bank, and other international agencies, but more effort is needed, especially incrementally improving sanitation and waste treatment as strategies to reduce AMR, both for human and animal fecal sources.…”

“…For example, researchers detected higher levels of emerging resistance genes, such as bla NDM‐1 (a carbapenem ARG), in water and sediment samples collected in the Upper Ganges River in northern India in June—at the beginning of the monsoons and coinciding with times of mass pilgrimages from urban areas—compared with February (one of the driest months) . Locations along the river with some fecal containment, such as latrines, had 4‐5 orders of magnitude lower CRE concentrations than stretches of the Ganges where there was open defecation …”

“…Antimicrobial resistance (AMR) is a global problem that impacts both human and animal health. Although AMR primarily derives from antibiotic and antimicrobial use, strong evidence suggests that wider spread of AMR is fueled by inadequate local sanitation, pollution, and other nonuse factors, with the natural environmental being an important conduit . Explaining AMR and then developing informed approaches to mitigate it are difficult because many technical, scientific, and behavioral factors come into play.…”

“…In turn, enteric ARB shed in feces can spread to other livestock and farm workers, reentering the environment and exposing other animals through drainage water and manure. This is analogous to AMR spread via human open defecation, which places raw fecal matter in close proximity to other individuals, increasing the risk of enteric ARB and ARG spread across human populations associated with poor sanitation …”

“…Although AMR primarily derives from antibiotic and antimicrobial use, strong evidence suggests that wider spread of AMR is fueled by inadequate local sanitation, pollution, and other nonuse factors, with the natural environmental being an important conduit. [1][2][3] Explaining AMR and then developing informed approaches to mitigate it are difficult because many technical, scientific, and behavioral factors come into play. Factors range from understanding the evolution of resistance at the molecular level within a given organism, to transmission mechanisms and pathways across organisms, to wider dissemination between human and animal hosts and across the wider environment, including soil and water.…”