title: Japanese encephalitis risk and contextual risk factors in southwest China: a Bayesian hierarchical spatial and spatiotemporal analysis.
abstract: It is valuable to study the spatiotemporal pattern of Japanese encephalitis (JE) and its association with the contextual risk factors in southwest China, which is the most endemic area in China. Using data from 2004 to 2009, we applied GISmapping and spatial autocorrelation analysis to analyze reported incidence data of JE in 438 counties in southwest China, finding that JE cases were not randomly distributed, and a Bayesian hierarchical spatiotemporal model identified the east part of southwest China as a high risk area. Meanwhile, the Bayesian hierarchical spatial model in 2006 demonstrated a statistically significant association between JE and the agricultural and climatic variables, including the proportion of rural population, the pig-to-human ratio, the monthly precipitation and the monthly mean minimum and maximum temperatures. Particular emphasis was placed on the time-lagged effect for climatic factors. The regression method and the Spearman correlation analysis both identified a two-month lag for the precipitation, while the regression method found a one-month lag for temperature. The results show that the high risk area in the east part of southwest China may be connected to the agricultural and climatic factors. The routine surveillance and the allocation of health resources should be given more attention in this area. Moreover, the meteorological variables might be considered as possible predictors of JE in southwest China.
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu 610041, China. zhaoxing731@gmail.com.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhao
authors.affiliation: School of Public Health, Xinjiang Medical University, Urumqi 830011, China. cmq66@126.com.
authors.forename: Mingqin
authors.initials: M
authors.lastname: Cao
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu 610041, China. 13211020002@fudan.edu.cn.
authors.forename: Hai-Huan
authors.initials: HH
authors.lastname: Feng
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu 610041, China. 13211020002@fudan.edu.cn.
authors.forename: Heng
authors.initials: H
authors.lastname: Fan
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu 610041, China. jacky2183@163.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Chen
authors.affiliation: Office for Disease Control and Emergency Response, Chinese Center for Disease Control and Prevention (China CDC), Beijing 102206, China. fengzj@chinacdc.cn.
authors.forename: Zijian
authors.initials: Z
authors.lastname: Feng
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu 610041, China. lixiaosong1101@126.com.
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Biostatistics, School of Public Health, University of Washington,Seattle, WA 98195, USA. azhou@u.washington.edu.
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000383:Agriculture; D001499:Bayes Theorem; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D002980:Climate; D004672:Encephalitis, Japanese / Q000453:epidemiology*; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D015994:Incidence; D008297:Male; D012307:Risk Factors; D062211:Spatio-Temporal Analysis; D013696:Temperature
references.citation: Epidemiol Infect. 2008 Jul;136(7):980-7
references.pmid: 17767793
references.citation: Annu Rev Entomol. 2002;47:1-31
references.pmid: 11729067
references.citation: J Med Entomol. 1992 May;29(3):436-44
references.pmid: 1320699
references.citation: PLoS Negl Trop Dis. 2013 Jun 20;7(6):e2285
references.pmid: 23819000
references.citation: Stat Med. 2000 Sep 15-30;19(17-18):2555-67
references.pmid: 10960871
references.citation: Clin Infect Dis. 2013 Mar;56(5):752
references.pmid: 23243182
references.citation: Spat Spatiotemporal Epidemiol. 2013 Mar;4:33-49
references.pmid: 23481252
references.citation: J Infect. 2007 Dec;55(6):551-6
references.pmid: 17714787
references.citation: Ecology. 2009 Apr;90(4):888-900
references.pmid: 19449681
references.citation: Trop Med Int Health. 2010 Aug;15(8):918-23
references.pmid: 20561307
references.citation: Jpn J Infect Dis. 2009 Sep;62(5):331-6
references.pmid: 19762980
references.citation: Public Health. 2012 Nov;126(11):909-19
references.pmid: 22981043
references.citation: PLoS Negl Trop Dis. 2013 Sep 12;7(9):e2208
references.pmid: 24069463
references.citation: Global Health. 2013 Mar 09;9:10
references.pmid: 23497420
references.citation: Int J Epidemiol. 1993 Dec;22(6):1193-202
references.pmid: 8144305
references.citation: Stat Med. 1999 Aug 30;18(16):2147-62
references.pmid: 10441770
references.citation: Vector Borne Zoonotic Dis. 2003 Fall;3(3):111-5
references.pmid: 14511580
references.citation: Emerg Infect Dis. 2009 Jan;15(1):1-7
references.pmid: 19116041
references.citation: BMC Public Health. 2009 Oct 27;9:395
references.pmid: 19860867
references.citation: Public Health Rep. 2003 Jan-Feb;118(1):65-71
references.pmid: 12604766
references.citation: PLoS One. 2011;6(7):e22192
references.pmid: 21811573
references.citation: Bull World Health Organ. 2011 Oct 1;89(10):766-74, 774A-774E
references.pmid: 22084515
references.citation: Acta Trop. 2005 Jul;95(1):40-57
references.pmid: 15878762
references.citation: PLoS Negl Trop Dis. 2010 Apr 27;4(4):e624
references.pmid: 20436960
references.citation: Int J Public Health. 2012 Apr;57(2):289-96
references.pmid: 21308477
references.citation: J Neurol Sci. 2007 Nov 15;262(1-2):165-70
references.pmid: 17643451
references.citation: Environ Health Perspect. 2004 Jun;112(9):998-1006
references.pmid: 15198920
references.citation: Trends Ecol Evol. 2011 Jun;26(6):270-7
references.pmid: 21481487
references.citation: Am J Trop Med Hyg. 2009 Sep;81(3):503-9
references.pmid: 19706922
references.citation: N Engl J Med. 2006 Aug 31;355(9):869-71
references.pmid: 16943399