Pathogen-specific response of infectious gastroenteritis to ambient temperature: National surveillance data in the Republic of Korea, 2015–2019

The objective of this study was to investigate the relationship between ambient temperature and common viral and bacterial gastroenteritis in the Republic of Korea, which has a high-income and temperate climate, considering the different lagged effects of each causative pathogen.We obtained the number of weekly reported cases of infectious gastroenteritis caused by norovirus, group A rotavirus, enteric adenovirus, Clostridium perfringens, non-typhoidal Salmonella, and Campylobacter between 2015 and 2019 from the Korean Infectious Diseases Sentinel Surveillance System. We obtained weather data from the Korea Meteorological Administration for the same period. Generalized linear models with quasi-Poisson distributions and distributed lag non-linear models were utilized after adjusting for relative humidity, precipitation, long-term trends, and seasonality. We investigated the associations between weekly mean temperature and the weekly number of reported cases of each type of infectious gastroenteritis by applying different maximum lags for each type.Compared with the 50th percentile temperature, the lag-cumulative relative risks (RRs) with 95% confidence intervals (CIs) at the 5th percentile temperature for norovirus gastroenteritis, rotavirus gastroenteritis, adenovirus gastroenteritis were 11.0 (4.7-25.7), 2.7 (1.4-5.2), and 4.7 (1.4-15.8) by applying the maximum lag of 6, 4, and 3 weeks, respectively. Compared with the 50th percentile temperature, the lag-cumulative RRs with 95% CIs at the 95th percentile temperature for C. perfringens gastroenteritis, Salmonella gastroenteritis, and Campylobacter gastroenteritis were 1.2 (0.8-1.9), 3.0 (1.5-6.2), and 2.0 (1.1-3.6), by applying the maximum lag of 2, 3, and 2 weeks, respectively.Cold temperature increased the risk of viral gastroenteritis and showed relatively long lagged effects. Hot temperature increased the risk of bacterial gastroenteritis and showed relatively short lagged effects.