Spatiotemporal pattern and risk factors of the reported novel avian-origin influenza A(H7N9) cases in China.
A total of 134 laboratory-confirmed human cases of the novel avian-origin influenza A(H7N9) were reported in China between February to July 2013. To illustrate the spatiotemporal patterns of H7N9 outbreaks in humans and investigate the risk factors associated with their distribution, we mapped the distribution of affected human cases and carried out directional distribution analysis and a direction test. We also collected data on anthropogenic, vegetation, climatic, and topographic factors, and used multiple logistic regression to examine the contribution of each factor. Two different spatiotemporal patterns were found: clustered and regular directional distributions in four distinct temporal phases in the Yangtze River Delta, and sporadic but spread in three direction across the provinces adjacent to the Yangtze River Delta. Mean monthly precipitation, mean monthly temperature, normalized difference vegetation index, and poultry consumption were significantly associated with the occurrence of human H7N9 infection. The model generated a map showing the high-risk areas for human H7N9 infection for mainland China. These findings provide an empirical basis for identifying priority areas for implementing preventive intervention to reduce the number of future human infections.
Key Laboratory of Monitoring and Estimate for Environment and Disaster of Hubei Province, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan, Hubei, PR China; University of Chinese Academy of Sciences, Beijing, PR China. Electronic address: qiujuan2011@gmail.com.
Juan
J
Qiu
Key Laboratory of Monitoring and Estimate for Environment and Disaster of Hubei Province, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan, Hubei, PR China.
Rendong
R
Li
Hubei Provincial Center for Disease Control and Prevention, Wuhan, Hubei, PR China.
Xingjian
X
Xu
Hubei Provincial Center for Disease Control and Prevention, Wuhan, Hubei, PR China.
Xicheng
X
Hong
Hubei Provincial Center for Disease Control and Prevention, Wuhan, Hubei, PR China.
Xin
X
Xia
School of Public Health & Global Health Institute, Wuhan University, Wuhan, Hubei, PR China.
Chuanhua
C
Yu
D006801:Humans; D002681:China / Q000453:epidemiology; D002980:Climate; D004032:Diet; D004196:Disease Outbreaks / Q000662:veterinary; D004777:Environment; D005843:Geography; D064766:Influenza A Virus, H7N9 Subtype / Q000502:physiology; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology; D012307:Risk Factors; D013997:Time Factors; D011202:Poultry Products; D008460:Meat; D058751:Livestock; D002645:Chickens; D004372:Ducks; D000818:Animals
Avian influenza; H7N9; Risk factors; Spatiotemporal analysis