Effect of Daily Precipitation on Enteric Virus Transmission in Maputo, Mozambique

Diarrheal diseases are common in low- and middle-income countries, and climate changes – including flooding and other extreme events – may influence how enteric pathogens are spread in underserved communities. However, much research into the relationship between precipitation and enteric pathogen detection in stool has not been done, as well as these relationships under the context of an intervention. We examined virus detection in child stool samples as part of a cross-sectional follow-up of children in the Maputo Sanitation trial. Using Poisson regression models, we estimated prevalence ratios to determine if and how precipitation levels were associated with viral pathogen detection under different precipitation conditions. We found that total viral prevalence and norovirus prevalence in child stools was lower during the drier season, by 27.7% and 46.0% respectively, and and adenovirus prevalence was lower when rainfall was above the calculated 75th percentile by 77.2%. In addition, we found that the sanitation upgrade modified the relationship between precipitation and viral prevalence detected in stool samples, with uncertain implications. Climate-resilient WASH interventions are needed to support public health while also combatting the impending climate crisis. Further research on the specific associations between sanitary infrastructure, climate, and health is warranted.