title: Herd-level risk factors for bovine tuberculosis and adoption of related biosecurity measures in Northern Ireland: A case-control study.
abstract: Bovine tuberculosis (bTB) is a zoonotic disease which is endemic in Northern Ireland. As it has proven difficult to eradicate this disease, partly due to a wildlife reservoir being present in the European badger (Meles meles), a case-control study was conducted in a high incidence area in 2010-2011. The aim was to identify risk factors for bTB breakdown relating to cattle and badgers, and to assess the adoption of bTB related biosecurity measures on farms. Face-to-face questionnaires with farmers and surveys of badger setts and farm boundaries were conducted on 117 farms with a recent bTB breakdown (cases) and 75 farms without a recent breakdown (controls). On logistic regression at univariable and multivariable levels, significant risk factors associated with being a case herd included having an accessible badger sett within the farm boundaries in a field grazed in the last year (odds ratio, OR, 4.14; 95% confidence interval, CI, 1.79, 9.55), observation of live badgers (OR 4.14; 95% CI 1.79, 9.55), purchase of beef cattle (OR 4.60; 95% CI 1.61, 13.13), use of contractors to spread slurry (OR 2.83; 95% CI 1.24, 6.49), feeding meal on top of silage (OR 3.55; 95% CI 1.53, 8.23) and feeding magnesium supplement (OR = 3.77; 95% CI 1.39, 10.17). The majority of setts within the farm boundary were stated to be accessible by cattle (77.1%; 95% CI 71.2, 83.0%) and 66.8% (95% CI 63.8, 69.7%) of farm boundaries provided opportunities for nose-to-nose contact between cattle. Adoption of bTB related biosecurity measures, especially with regards to purchasing cattle and badger-related measures, was lower than measures related to disinfection and washing.
authors.affiliation: Veterinary Sciences Division, Agri-Food and Biosciences Institute, Stoney Road, Belfast BT4 3SD, United Kingdom. Electronic address: Maria.O'Hagan@dardni.gov.uk.
authors.forename: M J H
authors.initials: MJ
authors.lastname: O'Hagan
authors.affiliation: Biometrics & Information Systems Branch, Agri-Food and Biosciences Institute, 18A Newforge Lane, Belfast BT9 5PX, United Kingdom.
authors.forename: D I
authors.initials: DI
authors.lastname: Matthews
authors.affiliation: Veterinary Sciences Division, Agri-Food and Biosciences Institute, Stoney Road, Belfast BT4 3SD, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Laird
authors.affiliation: Veterinary Sciences Division, Agri-Food and Biosciences Institute, Stoney Road, Belfast BT4 3SD, United Kingdom.
authors.forename: S W J
authors.initials: SW
authors.lastname: McDowell
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D016022:Case-Control Studies; D002417:Cattle; D016015:Logistic Models; D045969:Mustelidae / Q000382:microbiology; D009660:Northern Ireland; D016017:Odds Ratio; D012307:Risk Factors; D014380:Tuberculosis, Bovine / Q000382:microbiology / Q000517:prevention & control*
keywords: Biosecurity; Bovine tuberculosis; Case-control study; Mycobacterium bovis; Risk factors