Heterogeneous effects of tropical cyclones on diarrheal diseases across multiple Asian regions by cyclone definitions

Tropical cyclones (TCs) can elevate diarrheal disease risk yet inconsistent definitions and types of diarrheal data being used can obscure important heterogeneity. Here, we used harmonized weekly diarrheal mortality and morbidity data from 10 Asian regions between 2000 and 2021. We applied two-way fixed effects models to estimate TC-diarrhea associations across regions and compare associations across multiple TC definitions. These definitions include wind-based (wind intensity), rainfall-based (percentile threshold), and combined wind-rainfall metrics. We then assessed differences across a range of diarrheal outcomes. We found that mortality associations were generally not statistically significant and had wide confidence intervals across regions. For morbidity, we observed substantial heterogeneity across regions and definitions, with the greatest TC-attributable burden observed in Taiwan. These findings suggest that tailored TC definitions, calibrated to local health burden profiles, represent a promising strategy to improve early warning systems and guide interventions.