This study examines the impact of climatic factors on the burden of diarrheal disease among children under the age of five living in the Dhankuta, Morang, Surkhet, and Jajarkot districts of Nepal.

A time series study analyzed the monthly case counts of diarrheal disease among children under five years from 2002 to 2022. A generalized linear model with a quasi-Poisson distribution was applied to examine the relationship between climatic variables and diarrheal disease incidence.

In the Jajarkot district, the monsoon season was associated with a 26% increase in diarrheal disease incidence compared with non-monsoon seasons. In the Surkhet district, each 1 °C increase in maximum temperature was associated with a 4.7% increase in diarrheal cases, while each 1 °C increase in minimum temperature was associated with a 4.9% increase in diarrheal incidence. Similarly, in the Morang district, each 1 °C increase in maximum temperature was associated with a 9.6% increase in diarrheal cases, whereas each 1 °C increase in minimum temperature was associated with a 7% increase in diarrheal incidence. In the Dhankuta district, each 1 °C increase in minimum temperature was associated with a 10.3% increase in diarrheal incidence. Additionally, each 1 mm increase in rainfall was associated with a 0.9% increase in diarrheal disease incidence.

Our research identifies and quantifies the relationship between climate factors and the positive association of diarrheal disease. The findings suggest that ongoing climate change could contribute to increased infectious diseases in Nepal and the region. These findings provide evidence to inform public health prevention programs aimed at reducing diarrheal disease-related morbidity and mortality in South Asia.