The influence of temperature and humidity on the incidence of hand, foot, and mouth disease in Japan

BackgroundThe increasing evidence for rapid global climate change has highlighted the need for investigations examining the relationship between weather variability and infectious diseases. However, the impact of weather fluctuations on hand, foot, and mouth disease (HFMD), which primarily affects children, is not well understood.MethodsWe acquired data related to cases of HFMD and weather parameters of temperature and humidity in Fukuoka, Japan between 2000 and 2010, and used time-series analyses to assess the possible relationship of weather variability with pediatric HFMD cases, adjusting for seasonal and interannual variations.ResultsOur analysis revealed that the weekly number of HFMD cases increased by 11.2% (95% CI: 3.2–19.8) for every 1 °C increase in average temperature and by 4.7% (95% CI: 2.4–7.2) for every 1% increase in relative humidity. Notably, the effects of temperature and humidity on HFMD infection were most significant in children under the age of 10 years.ConclusionsOur study provides quantitative evidence that the number of HFMD cases increased significantly with increasing average temperature and relative humidity, and suggests that preventive measures for limiting the spread of HFMD, particularly in younger children, should be considered during extended periods of high temperature and humidity.

► We estimated the relationship of weather variability with pediatric HFMD cases. ► HFMD cases increased with increasing average temperature and relative humidity. ► This increase was most remarkable in children aged less than 10 years. ► Weather factors have a significant influence on the incidence of HFMD infections.