title: Risk factors for bunyavirus-associated severe Fever with thrombocytopenia syndrome, china.
abstract: BACKGROUND
  Severe fever with thrombocytopenia syndrome (SFTS) is an emerging disease that is caused by a novel bunyavirus, referred to as SFTS virus. During January 2011 to December 2011 we conducted a case-control study in Henan, Hubei and Shandong Provinces of China to determine the risk factors for SFTS.
  
  
  METHODS
  Case-patients were identified in hospitals and reported to provincial Centers for Disease Control and Prevention while being notified electronically to the National Surveillance System. Controls were randomly selected from a pool of patients admitted to the same hospital ward within one week of the inclusion of the cases. They were matched by age (+/-5 years) and gender.
  
  
  RESULTS
  A total of 422 patients participated in the study including 134 cases and 288 matched controls. The median age of the cases was 58.8 years, ranging from 47.6 to 70.1 years; 54.5% were male. No differences in demographics were observed between cases and controls; however, farmers were frequent and more common among cases (88.8%) than controls (58.7%). In multivariate analysis, the odds for SFTS was 2.4∼4.5 fold higher with patients who reported tick bites or presence of tick in the living area. Other independent risk factors included cat or cattle ownership and reported presence of weeds and shrubs in the working environment.
  
  
  CONCLUSIONS
  Our findings support the hypothesis that ticks are important vectors of SFTS virus. Further investigations are warranted to understand the detailed modes of transmission of SFTS virus while vector management, education on tick bites prevention and personal hygiene management should be implemented for high-risk groups in high incidence areas.
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing, P.R. China.
authors.forename: Fan
authors.initials: F
authors.lastname: Ding
authors.affiliation: Institute of Infectious Disease Control and Prevention, Hubei Provincial Center for Disease Control and Prevention, Hubei, P.R. China.
authors.forename: Xu-Hua
authors.initials: XH
authors.lastname: Guan
authors.affiliation: Institute of infection Disease Control and Prevention, Henan Provincial Center for Disease Control and Prevention, Zhengzhou, P.R. China.
authors.forename: Kai
authors.initials: K
authors.lastname: Kang
authors.affiliation: Shandong Center for Disease Control and Prevention, Shandong Provincial Key Laboratory of Communicable Disease Control and Prevention, Jinan, China.
authors.forename: Shu-Jun
authors.initials: SJ
authors.lastname: Ding
authors.affiliation: Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China.
authors.forename: Li-Yong
authors.initials: LY
authors.lastname: Huang
authors.affiliation: Institute of Infectious Disease Control and Prevention, Hubei Provincial Center for Disease Control and Prevention, Hubei, P.R. China.
authors.forename: Xue-Sen
authors.initials: XS
authors.lastname: Xing
authors.affiliation: Institute of Infectious Disease Control and Prevention, Hubei Provincial Center for Disease Control and Prevention, Hubei, P.R. China.
authors.forename: Sha
authors.initials: S
authors.lastname: Sha
authors.affiliation: Institute of Infectious Disease Control and Prevention, Hubei Provincial Center for Disease Control and Prevention, Hubei, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: Shandong Center for Disease Control and Prevention, Shandong Provincial Key Laboratory of Communicable Disease Control and Prevention, Jinan, China.
authors.forename: Xian-Jun
authors.initials: XJ
authors.lastname: Wang
authors.affiliation: Shandong Center for Disease Control and Prevention, Shandong Provincial Key Laboratory of Communicable Disease Control and Prevention, Jinan, China.
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Zhang
authors.affiliation: Institute of infection Disease Control and Prevention, Henan Provincial Center for Disease Control and Prevention, Zhengzhou, P.R. China.
authors.forename: Ai-Guo
authors.initials: AG
authors.lastname: You
authors.affiliation: Institute of infection Disease Control and Prevention, Henan Provincial Center for Disease Control and Prevention, Zhengzhou, P.R. China.
authors.forename: Yan-Hua
authors.initials: YH
authors.lastname: Du
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Zhou
authors.affiliation: World Health Organization (WHO), Representative Office in China, Beijing, China.
authors.forename: Sirenda
authors.initials: S
authors.lastname: Vong
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Zhang
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing, P.R. China.
authors.forename: Zi-Jian
authors.initials: ZJ
authors.lastname: Feng
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing, P.R. China.
authors.forename: Wei-Zhong
authors.initials: WZ
authors.lastname: Yang
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing, P.R. China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Li
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Wen-Wu
authors.initials: WW
authors.lastname: Yin
mesh_terms: D000368:Aged; D000818:Animals; D002044:Bunyaviridae Infections / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D016022:Case-Control Studies; D002415:Cats; D002417:Cattle; D002681:China / Q000453:epidemiology; D003710:Demography; D004777:Environment; D005260:Female; D006801:Humans; D006920:Hygiene; D015994:Incidence; D007303:Insect Vectors / Q000821:virology; D008297:Male; D008875:Middle Aged; D010217:Phlebotomus Fever / Q000453:epidemiology* / Q000635:transmission; D016856:Phlebovirus / Q000145:classification* / Q000235:genetics; D012307:Risk Factors; D013921:Thrombocytopenia / Q000453:epidemiology* / Q000821:virology; D013987:Ticks / Q000821:virology