title: Lack of association between the occurrence of Crohn's disease and occupational exposure to dairy and beef cattle herds infected with Mycobacterium avium subspecies paratuberculosis.
abstract: A cross-sectional survey was conducted to identify associations between Crohn's disease (CD) and Mycobacterium avium ssp. paratuberculosis (Map) exposure. A questionnaire was used to collect information on exposure to cattle infected with Map, and personal and family history of CD in dairy and beef cattle producers with and without Map-infected herds, and in veterinarians who did or did not have contact with Map-infected herds. Cases of CD were selected from respondents and matched 1:4 with controls on occupation, age, and sex. Multivariable conditional logistic regression was used to assess associations between Map exposure and CD. There were 3 cases of CD in 702 producers and 4 cases in 774 veterinarians, yielding a prevalence of 0.47%. No association was found between exposure to JD and CD in any phase of the analysis. However, the number of cases of CD is not large and limits the power to detect important differences.
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames 50014, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Qual
authors.forename: J B
authors.initials: JB
authors.lastname: Kaneene
authors.forename: T J
authors.initials: TJ
authors.lastname: Varty
authors.forename: R
authors.initials: R
authors.lastname: Miller
authors.forename: C O
authors.initials: CO
authors.lastname: Thoen
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D016001:Confidence Intervals; D003424:Crohn Disease / Q000209:etiology*; D003430:Cross-Sectional Studies; D003612:Dairying; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D016015:Logistic Models; D008297:Male; D016927:Mycobacterium avium subsp. paratuberculosis; D016273:Occupational Exposure / Q000009:adverse effects*; D016017:Odds Ratio; D010283:Paratuberculosis / Q000382:microbiology*; D012307:Risk Factors; D014730:Veterinary Medicine