Background and Aim: Diarrheal diseases continue to be a major disease burden in developing countries. Although studies described the seasonality of diarrheal diseases, the association of weather variables with diarrheal diseases has not been well characterized in resource-limited settings where the burden remains high. This study examines the short-term associations between weather and hospital visits due to diarrhoea in children in seven low-income and middle-income countries.

Method: The primary health outcome was hospital visits due to diarrhoea among children under five years of age. The data were collected from seven sites in each country via the Global Enteric Multicenter Study project from December 2007 to March 2011. Daily weather data in the same period were downloaded from the ERA5-Land. For each of the seven sites, we fitted a time series regression model to examine the relationship of daily diarrhoeal cases with daily ambient temperature and precipitation for the last 21 days using a generalized linear model with distributed lag nonlinear functions.

Results: The analysis included 66,056 cases of diarrhoea. Daily mean temperatures ranged from 15.2 °C in Bangladesh to 37.7 °C in Mali over the study period. Sites had a highly skewed distribution of precipitations. The associations of diarrhoeal hospital visits with temperature and precipitation varied by country. The relative risk (RR) of diarrhoeal visits for temperature exposure (95^th percentile vs. 1^st percentile) ranged from 0.24 to 8.07, with Mozambique, and Bangladesh showing positive associations, while Mali and Pakistan having negative associations. The RR for precipitation (95^th percentile vs. 1^st percentile) ranged from 0.77 to 1.55, with Mali and India showing positive associations, while the only negative association was observed in Pakistan.

Conclusion: Our findings suggest the essential roles of ambient temperatures and precipitations, especially high temperatures and high precipitation, in increasing diarrhoeal infection both in south Asia and sub-Saharan African countries.