Warmer Temperatures Linked to Lower Viral Gastroenteritis Risk in Children, Study Finds

Recent outdoor temperatures may help clinicians determine whether a virus is driving a pediatric case of infectious gastroenteritis, according to a secondary analysis of a prospective trial published in Open Forum Infectious Diseases.

Among more than 800 children and adolescents presenting to emergency departments with acute gastroenteritis, a one standard-deviation increase in average daily temperature over the preceding 14 days was associated with a 50% lower likelihood of a viral etiology (OR 0.50, 95% CI 0.36–0.68, P<0.001).

The inverse relationship between temperature and viral gastroenteritis was particularly pronounced in older children. Compared with children under 2 years of age, those aged 12 years and older were 83% less likely to have viral infectious gastroenteritis when the prior two-week temperatures rose by one standard deviation (OR 0.17, 95% CI 0.09–0.33, P<0.001).

In contrast, prior precipitation, humidity, and air pollution levels showed no significant effect on viral gastroenteritis risk (P>0.05), reported Natalya Alekhina, PhD, of the University of Utah School of Medicine, and colleagues.

“Incorporating weather variables alongside other clinical and patient-level factors into clinical prediction tools may help prioritize diagnostic testing, minimize unnecessary antibiotic use, and improve the timely diagnosis and management of infectious gastroenteritis,” the authors wrote.

Infectious gastroenteritis remains a major cause of pediatric illness and exhibits well-established seasonal patterns. Viral pathogens—most notably norovirus and rotavirus—typically peak during winter months. While laboratory diagnostics guide management, excessive testing imposes financial costs and can contribute to inappropriate antimicrobial use.

“As weather patterns vary year to year and with changing climate, weather-informed models are likely to prove superior to those based on season alone,” Alekhina and colleagues noted. “Weather-informed surveillance models can enhance the accuracy of seasonal outbreak predictions and optimize healthcare delivery during seasonal surges.”

The primary IMPACT study, conducted from March 2015 to August 2016, assessed the clinical impact of routine molecular multiplex testing in children presenting with acute gastroenteritis. That analysis found the intervention was associated with a 21% reduction in the odds of any return visit (OR 0.79, 95% CI 0.70–0.90) after adjustment for confounders.

The current analysis included 868 IMPACT participants who submitted stool samples. Of these, 38.8% had viral-only infectious gastroenteritis; 26.8% had nonviral or mixed viral, bacterial, or protozoal etiologies; and 34.3% had no detected pathogen. Most children with viral gastroenteritis were under 2 years old (57.3%).

The researchers validated their individual-patient findings using population-level surveillance data from GermWatch, a regional infectious disease system in Utah that aggregates stool testing results from children and adults. GermWatch data likewise demonstrated an inverse relationship between higher prior temperatures and lower proportions of viral gastroenteritis cases.

In the two Utah counties with the highest GermWatch stool-testing coverage, higher average monthly temperatures were significantly associated with a lower proportion of viral cases, with a 0.52-percentage-point drop in the viral proportion for every 1°F rise in mean temperature (P=0.002).

Study limitations included the use of patient data from the continental U.S. and population-level data from Utah, which may limit generalizability. The relatively short study duration may also have restricted the ability to detect long-term seasonal patterns or rare events.

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