title: The role of environmental factors in the spatial distribution of Japanese encephalitis in mainland China.
abstract: Japanese encephalitis (JE) is the most common cause of viral encephalitis and an important public health concern in the Asia-Pacific region, particularly in China where 50% of global cases are notified. To explore the association between environmental factors and human JE cases and identify the high risk areas for JE transmission in China, we used annual notified data on JE cases at the center of administrative township and environmental variables with a pixel resolution of 1 km×1 km from 2005 to 2011 to construct models using ecological niche modeling (ENM) approaches based on maximum entropy. These models were then validated by overlaying reported human JE case localities from 2006 to 2012 onto each prediction map. ENMs had good discriminatory ability with the area under the curve (AUC) of the receiver operating curve (ROC) of 0.82-0.91, and low extrinsic omission rate of 5.44-7.42%. Resulting maps showed JE being presented extensively throughout southwestern and central China, with local spatial variations in probability influenced by minimum temperatures, human population density, mean temperatures, and elevation, with contribution of 17.94%-38.37%, 15.47%-21.82%, 3.86%-21.22%, and 12.05%-16.02%, respectively. Approximately 60% of JE cases occurred in predicted high risk areas, which covered less than 6% of areas in mainland China. Our findings will help inform optimal geographical allocation of the limited resources available for JE prevention and control in China, find hidden high-risk areas, and increase the effectiveness of public health interventions against JE transmission.
authors: Institute of Disease Control and Prevention, Academy of Military Medical Science, Beijing, People's Republic of China.
authors: Liya
authors: L
authors: Wang
authors: School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia.
authors: Wenbiao
authors: W
authors: Hu
authors: University of Queensland, Infectious Disease Epidemiology Unit, School of Population Health, Australia.
authors: Ricardo J
authors: RJ
authors: Soares Magalhaes
authors: Discipline of Public Health, University of Adelaide, Adelaide, Australia.
authors: Peng
authors: P
authors: Bi
authors: Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors: Fan
authors: F
authors: Ding
authors: Institute of Disease Control and Prevention, Academy of Military Medical Science, Beijing, People's Republic of China.
authors: Hailong
authors: H
authors: Sun
authors: Institute of Disease Control and Prevention, Academy of Military Medical Science, Beijing, People's Republic of China.
authors: Shenlong
authors: S
authors: Li
authors: Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors: Wenwu
authors: W
authors: Yin
authors: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
authors: Lan
authors: L
authors: Wei
authors: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, People's Republic of China.
authors: Qiyong
authors: Q
authors: Liu
authors: W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
authors: Ubydul
authors: U
authors: Haque
authors: Institute of Disease Control and Prevention, Academy of Military Medical Science, Beijing, People's Republic of China.
authors: Yansong
authors: Y
authors: Sun
authors: Institute of Disease Control and Prevention, Academy of Military Medical Science, Beijing, People's Republic of China.
authors: Liuyu
authors: L
authors: Huang
authors: School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia.
authors: Shilu
authors: S
authors: Tong
authors: Research School of Population Health, The Australian National University, Canberra, ACT, Australia.
authors: Archie C A
authors: AC
authors: Clements
authors: Institute of Disease Control and Prevention, Academy of Military Medical Science, Beijing, People's Republic of China. Electronic address: zwy0419@126.com.
authors: Wenyi
authors: W
authors: Zhang
authors: Institute of Disease Control and Prevention, Academy of Military Medical Science, Beijing, People's Republic of China. Electronic address: licy_60@163.com.
authors: Chengyi
authors: C
authors: Li
mesh_terms: D002681:China / Q000453:epidemiology; D004672:Encephalitis, Japanese / Q000453:epidemiology*; D004777:Environment; D006801:Humans; D012306:Risk; D013696:Temperature
keywords: China; Ecological niche model; Japanese encephalitis; MaxEnt