title: Factors related to the prevalence of pathogenic Yersinia enterocolitica on pig             farms.
abstract: A survey of 788 pigs from 120 farms was conducted to determine the within-farm prevalence of pathogenic Yersinia enterocolitica and a questionnaire of management conditions was mailed to the farms afterwards. A univariate statistical analysis with carriage and shedding as outcomes was conducted with random-effects logistic regression with farm as a clustering factor. Variables with a P value <0·15 were included into the respective multivariate random-effects logistic regression model. The use of municipal water was discovered to be a protective factor against carriage and faecal shedding of the pathogen. Organic production and buying feed from a certain feed manufacturer were also protective against total carriage. Tonsillar carriage, a different feed manufacturer, fasting pigs before transport to the slaughterhouse, higher-level farm health classification, and snout contacts between pigs were risk factors for faecal shedding. We concluded that differences in management can explain different prevalences of Y. enterocolitica between farms.
authors.affiliation: Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Finland. sonja.virtanen@helsinki.fi
authors.forename: S E
authors.initials: SE
authors.lastname: Virtanen
authors.forename: L K
authors.initials: LK
authors.lastname: Salonen
authors.forename: R
authors.initials: R
authors.lastname: Laukkanen
authors.forename: M
authors.initials: M
authors.lastname: Hakkinen
authors.forename: H
authors.initials: H
authors.lastname: Korkeala
mesh_terms: D000383:Agriculture / Q000458:organization & administration*; D000818:Animals; D057138:Bacterial Shedding; D005387:Finland; D016015:Logistic Models; D015999:Multivariate Analysis; D015995:Prevalence; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D015009:Yersinia Infections / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission / Q000662:veterinary*; D015008:Yersinia enterocolitica / Q000302:isolation & purification*