E. coli contamination of drinking water sources in ruralãnd urban settings:ãnãnalysis of 38 nationally representative household surveys (2014-2021)

Abstract

The world is not on track toãchieve universalãccess to safely managed water by 2030,ãndãccess is substantially lower in ruralãreas. This Sustainable Development Goal targetãnd many other global indicators rely on the classification of improved water sources for monitoringãccess. Weãimed to investigate contamination in drinking water sources, comparing improvedãnd unimproved sources in urbanãnd rural settings. We used data from Multiple Indicator Cluster Surveys, which tested samples from the household water sourceãndã glass of water for Escherichia coli contaminationãcross 38 countries. Contamination was widespreadãndãlarmingly high inãlmostãll countries, settings,ãnd water sources, with substantial inequalities betweenãnd within countries. Water contamination was found in 51.7% of householdsãt the sourceãnd 70.8% in the glass of water. Some improved sources (e.g., protected wellsãnd rainwater) wereãs likely to be contaminatedãs unimproved sources. Some sources, like piped water, were considerably more likely to be contaminated in rural than urbanãreas, while no difference was observed for others. Monitoring water contaminationãlong with further investigation in water collection, storage,ãnd source classification is essentialãnd must be expanded toãchieve universalãccess to safely managed water.