Long-term Drought and Diarrhea among Children under Five and the Role of Water, Sanitation, and Hygiene Practices

Abstract

Background and Aim. Climate change is projected to intensify drought conditions, which may increase the risk of diarrheal diseases in children. However, evidence on the association between drought and diarrhea risk is scarce. This study aimed to quantify this association among children under five in 51 low- and middle-income countries (LMICs). Methods. Data on childhood diarrhea during 1990-2019 were obtained from the Demographic and Health Surveys program. Drought was represented by the 6-to-24-month scale Standardized Precipitation Evapotranspiration Index at ~9km resolution and was further dichotomized into mild or severe drought. Log-binomial generalized linear mixed models with random effects for survey cluster were constructed to examine the association, adjusting for sociodemographic characteristics. The mediating and interacting effects of water, sanitation, and hygiene-related (WASH) practices were evaluated. Results. Exposure to 6-month mild or severe drought was associated with an increased diarrhea risk of 5% (95% confidence interval 3%–7%) or 8% (5%–11%), respectively. The strongest association for severe drought was observed at the timescale of 6 months, whereas the association for mild drought exhibited a light, graded increase across 6 to 24 month timescales. WASH mediated 11.6% or 19.5% of the association with 6-month mild or severe drought, respectively. The association was stronger among children living in a household that needed longer time to collect water or had no access to water or soap/detergent for handwashing. The association for 24-month drought was strong in dry zones but weak or null in tropical or temperate zones, whereas for 6-month drought the association was only observed in tropical or temperate zones. Conclusions. We observed associations between exposure to long-term drought and elevated diarrhea risk among children under five in LMICs. Our results suggest that the risk could be reduced through improved WASH practices.