Deep Tubewell Use and Child Diarrhea in Rural Bangladesh: Results from a Prospective Community Surveillance Study.

BACKGROUND: Diarrheal diseases remain a leading cause of mortality and morbidity among under-five children in South Asia. In rural Bangladesh, deep tubewells that tap into low-arsenic deep aquifers have been installed to provide microbially safe and arsenic-free drinking water at the source. However, unlike more widely used shallow tubewells, deep tubewells are sparsely distributed, and households often travel farther for drinking-water consumption from such wells. Hence, benefits from deep tubewells may be abated by higher levels of microbial contamination during water handling and storage that could increase the risk of diarrheal diseases. OBJECTIVES: We examined the association between deep tubewell use and diarrheal disease risk in under-five children and investigated the role of social and environmental factors on modifying the association. METHODS: We implemented community diarrheal disease surveillance across households with under-five children using deep and shallow tubewells in Matlab, Bangladesh from March 2018 to October 2019. We used Generalized Estimating Equations (GEE) to estimate the association between deep tubewell versus shallow tubewell use and diarrheal disease prevalence. RESULTS: Children in households using deep tubewells had diarrheal disease prevalence 0.83 times that of children in households using shallow tubewells (95% confidence interval (CI): 0.71-0.96). Protective effects of deep tubewell use on diarrhea risk were observed among children in households that drank from wells within their household compound (risk ratio (RR) = 0.70, 95% CI: 0.54 - 0.91), were in flood-prone areas (RR = 0.83, 95% CI: 0.75 - 0.92), and used unimproved latrines (RR = 0.62, 95% CI: 0.43-0.89). Deep tubewell use was more protective against diarrhea than shallow tubewell use during the dry season (RR = 0.71, 95% CI: 0.52-0.97). CONCLUSIONS: Despite concerns, using deep tubewells may not translate to higher diarrhea risk among under-five children and may reduce diarrhea further, especially in social and environmental contexts associated with higher groundwater microbial contamination.