In the absence of improvements in hygiene, climate change is expected to increase the incidence of diarrhoeal disease, a leading cause of childhood mortality and morbidity.

Diarrhoea accounts for approximately 500,000 deaths annually in children under age five, with most of the burden concentrated in areas with poor hygiene such as sub-Saharan Africa and South Asia. Even a small increase in diarrhoea risk can result in a substantial increase in global burden of disease.

However, our understanding of the burden of childhood diarrhoea attributable to climate change is hampered by the scarcity and inconsistency of empirical evidence on the relationship between extreme precipitation, floods, or droughts and diarrhoea, especially in low- and middle-income countries (LMICs). It also remains unclear whether water, sanitation, and hygiene (WaSH) practices could modify these associations, a critical knowledge gap in reducing the diarrhoeal disease burden under climate change.

Using Demographic and Health Surveys (DHS) data covering 51 LMICs in sub-Saharan Africa, South and Southeast Asia, Latin America, and the Caribbean, this research applies statistical modelling to estimate the relationship between extreme precipitation, floods, or drought and risk of childhood diarrhoea, and to evaluate whether these effects are modified by WaSH practices. In addition, researchers are collecting geo-referenced data from the Multiple Indicator Cluster Surveys (MICS) in a sensitivity analysis.

This research furthers our understanding of the potential impacts of climate change on diarrhoeal disease in LMICs and helps prioritise adaptation measures such as improved structural and individual-level hygiene practices.