Impacts of tropical cyclones and accompanying precipitation and wind velocity on childhood hand, foot and mouth disease in Guangdong Province, China

Abstract

ObjectiveGuangdong province is one of the provinces most frequently hit by tropical cyclones in China. Hand, foot and mouth disease (HFMD) continues to severely affect public health across the world. Our study aimed to evaluate the impacts of different grades of tropical cyclones and accompanying precipitation and wind velocity on HFMD among children younger than 6 years old in Guangdong province from 2009 to 2013. MethodsA time-stratified case-crossover design was used to examine the association between tropical cyclones and childhood HFMD. Principal component analysis (PCA) was first used to eliminate multicollinearity among meteorological variables. Conditional Poisson regression was then applied to calculate odds ratios (ORs) and the 95% confidence intervals (CIs). ResultsTropical storms increased the risk of HFMD among children below 6 years of age on lag 4 days (OR = 1.55, 95%CI: 1.28–1.88). Tropical storms were also a risk factor for boys below 3 years of age, boys between 3 and 6 and girls below 3 years of age with the largest OR = 1.52 (95%CI:1.15–2.00), OR = 1.81 (95%CI = 1.21–2.71) and OR = 1.51 (95%CI = 1.04–2.19), respectively. Precipitation during tropical cyclones had an adverse effect on childhood HFMD when reaching 25–49.9 mm or above 100 mm with OR = 1.20 (95%CI = 1.00–1.43) on lag 0 day and OR = 1.25 (95%CI = 1.04–1.49) on lag 7 days, respectively. For extreme wind velocity during tropical cyclones, the impact on childhood HFMD was largest on the day tropical cyclones landed (OR = 1.25, 95%CI: 1.06–1.48) with winds up to 13.9–24.4 m/s. ConclusionsTropical storms can increase the risk of HFMD among children younger than 3 years old, especially boys between 3 and 6 years old. Precipitation during tropical cyclones is a risk factor for childhood HFMD when it is between 25 and 49.9 mm or above 100 mm. As extreme wind velocity reaches 13.9–24.4 m/s, it has an adverse effect on children's health. Children below 3 years old and boys between 3 and 6 should be given more consideration during tropical storms.