title: Risk factors for the transmission of foot-and-mouth disease during the 2010 outbreak in Japan: a case-control study.
abstract: BACKGROUND
  In 2010, foot-and-mouth disease (FMD) occurred for the first time in a decade in Japan. Movement or shipment of people and animals around infected farms was restricted; however these contingency measures proved insufficient to prevent FMD spread. Consequently, a total of 292 farms were confirmed as infected during this outbreak. We conducted a case-control study to identify the risk factors associated with FMD transmission between farms during these restrictions. As there was discordance in the control measures taken, risk factors were examined separately for two areas. Analyses were also performed separately for cattle and pig farms given their different infectivity and susceptibility.
  
  
  RESULTS
  For cattle farms in the movement restriction area, the odds of having the factor 'farm equipment was shared with other farms' was significantly higher for case farms than for control farms. For cattle farms in the shipment restriction area, the odds of having the factors 'feed transport vehicles visited the farm' and 'staff of livestock-related companies visited the farm' were significantly higher on case farms than control farms. In pig farms in the movement restriction area, the odds of having factor 'farm staff commuted from outside' was 20 times higher for case farms than control farms. In addition, case farms were less likely to have the factors 'fattening farm' and 'barn has physical barriers' compared with control farms.
  
  
  CONCLUSIONS
  In the movement restriction area, the disease was likely to spread regardless of the movement of people and vehicles, and physical barriers were found to be a protective factor. Therefore, physical barriers from the surrounding environments seemed to prevent farms from being infected. Conversely, in the shipment restriction area, movement of people and vehicles was strongly associated with disease spread. These results allow a better understanding of the risk factors associated with FMD transmission and are useful to enhance future preventive measures against transmission during FMD outbreaks.
authors.affiliation: Viral Disease and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Muroga
authors.forename: Sota
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishida
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hayama
authors.forename: Takaaki
authors.initials: T
authors.lastname: Kawano
authors.forename: Takehisa
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tsutsui
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D016022:Case-Control Studies; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000635:transmission; D004196:Disease Outbreaks / Q000662:veterinary; D005536:Foot-and-Mouth Disease / Q000453:epidemiology / Q000635:transmission*; D007564:Japan / Q000453:epidemiology; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013552:Swine