Floods Increase the Risks of Hand-Foot-Mouth Disease in Qingdao, China, 2009-2013: A Quantitative Analysis

Background: We aimed to quantify the impact of few times floods on hand-foot-mouth disease (HFMD) in Qingdao during 2009-2013. Methods: The Spearman correlation test was applied to examine the lagged effects of floods on monthly morbidity of HFMD during study period in Qingdao. We further quantified the effects of 5 flood events on the morbidity of HFMD using the time-series Poisson regression controlling for climatic factors, seasonality, and lagged effects among different populations. Results: A total of 55,920 cases of HFMD were reported in the study region over the study period. The relative risks of floods on the morbidity of HFMD among the total population, males, females, under 1-2 years old, and 3-5 years old were 1.178. 1.165, 1.198, 1.338, and 1.245, respectively. Conclusions: This study has, for the first time, provided the positive evidence of the impact of floods on HFMD. it demonstrates that floods can significantly increase the risk of HFMD during study period. Additionally, among the different populations, the risks were higher among children under 1-5 years old.