title: Impacts of different grades of tropical cyclones on infectious diarrhea in Guangdong, 2005-2011.
abstract: OBJECTIVE
  Guangdong province is one of the most vulnerable provinces to tropical cyclones in China. Most prior studies concentrated on the relationship between tropical cyclones and injuries and mortality. This study aimed to explore the impacts of different grades of tropical cyclones on infectious diarrhea incidence in Guangdong province, from 2005 to 2011.
  
  
  METHODS
  Mann-Whitney U test was firstly used to examine if infectious diarrhea were sensitive to tropical cyclone. Then unidirectional 1:1 case-crossover design was performed to quantitatively evaluate the relationship between daily number of infectious diarrhea and tropical cyclone from 2005 to 2011 in Guangdong, China. Principal component analysis (PCA) was applied to eliminate multicollinearity. Multivariate logistic regression model was used to estimate the hazard ratios (HRs) and the 95% confidence intervals (CI).
  
  
  RESULTS
  There were no significant relationships between tropical cyclone and bacillary dysentery, amebic dysentery, typhoid, and paratyphoid cases. Infectious diarrhea other than cholera, dysentery, typhoid and paratyphoid significantly increased after tropical cyclones. The strongest effect were shown on lag 1 day (HRs = 1.95, 95%CI = 1.22, 3.12) and no lagged effect was detected for tropical depression, tropical storm, severe tropical storm and typhoon, with the largest HRs (95%CI) of 2.16 (95%CI = 1.69, 2.76), 2.43 (95%CI = 1.65, 3.58) and 2.21 (95%CI = 1.65, 2.69), respectively. Among children below 5 years old, the impacts of all grades of tropical cyclones were strongest at lag 0 day. And HRs were 2.67 (95%CI = 1.10, 6.48), 2.49 (95%CI = 1.80, 3.44), 4.89 (95%CI = 2.37, 7.37) and 3.18 (95%CI = 2.10, 4.81), respectively.
  
  
  CONCLUSIONS
  All grades of tropical cyclones could increase risk of other infectious diarrhea. Severe tropical storm has the strongest influence on other infectious diarrhea. The impacts of tropical cyclones on children under 5 years old were higher than total population.
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, Jinan, Shandong, People's Republic of China.
authors.forename: Ruihua
authors.initials: R
authors.lastname: Kang
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, Jinan, Shandong, People's Republic of China; Shandong University Climate Change and Health Center, Jinan, Shandong, People's Republic of China.
authors.forename: Huanmiao
authors.initials: H
authors.lastname: Xun
authors.affiliation: School of Public Health, University of Sydney, Sydney, Australia.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, Jinan, Shandong, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, Jinan, Shandong, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, Jinan, Shandong, People's Republic of China; Shandong University Climate Change and Health Center, Jinan, Shandong, People's Republic of China.
authors.forename: Baofa
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, Jinan, Shandong, People's Republic of China; Shandong University Climate Change and Health Center, Jinan, Shandong, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ma
mesh_terms: D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D018592:Cross-Over Studies; D055867:Cyclonic Storms / Q000145:classification*; D003967:Diarrhea / Q000453:epidemiology* / Q000382:microbiology*; D004404:Dysentery, Amebic / Q000453:epidemiology; D004405:Dysentery, Bacillary / Q000453:epidemiology; D005260:Female; D005843:Geography; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015999:Multivariate Analysis; D025341:Principal Component Analysis; D016016:Proportional Hazards Models; D012306:Risk; D014435:Typhoid Fever / Q000453:epidemiology; D014887:Weather