title: Fasciola hepatica is associated with the failure to detect bovine tuberculosis             in dairy cattle.
abstract: Bovine tuberculosis (BTB) is a significant and intractable disease of cattle caused                 by Mycobacterium bovis. In the United Kingdom, despite an aggressive                 eradication programme, the prevalence of BTB is increasing with an unexplained,                 exponential rise in cases year on year. Here we show in a study involving 3,026                 dairy herds in England and Wales that there is a significant negative association                 between exposure to the common, ubiquitous helminth parasite, Fasciola                     hepatica and diagnosis of BTB. The magnitude of the single intradermal                 comparative cervical tuberculin test used to diagnose BTB is reduced in cattle                 experimentally co-infected with M. bovis and F. hepatica. We estimate                 an under-ascertainment rate of about one-third (95% confidence interval                 27-38%) among our study farms, in the hypothetical situation of no                 exposure to F. hepatica. This finding may in part explain the continuing                 spread of BTB and the failure of the current eradication programme in the United                 Kingdom.
authors.affiliation: Institute of Infection and Global Health and School of Veterinary Science, University of Liverpool, Liverpool, L69 7ZJ, UK.
authors.forename: Jen
authors.initials: J
authors.lastname: Claridge
authors.affiliation: Division of Medicine, University of Lancaster, Lancaster, LA1 4YB, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Diggle
authors.affiliation: Institute of Infection and Global Health and School of Veterinary Science, University of Liverpool, Liverpool, L69 7ZJ, UK.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: McCann
authors.affiliation: School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Grace
authors.initials: G
authors.lastname: Mulcahy
authors.affiliation: School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Rob
authors.initials: R
authors.lastname: Flynn
authors.affiliation: Agri-Food and Biosciences Institute, Bacteriology Department, Veterinary Sciences Division, Stormont, Belfast BT4 3SD, UK.
authors.forename: Jim
authors.initials: J
authors.lastname: McNair
authors.affiliation: Agri-Food and Biosciences Institute, Bacteriology Department, Veterinary Sciences Division, Stormont, Belfast BT4 3SD, UK.
authors.forename: Sam
authors.initials: S
authors.lastname: Strain
authors.affiliation: Agri-Food and Biosciences Institute, Bacteriology Department, Veterinary Sciences Division, Stormont, Belfast BT4 3SD, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Welsh
authors.affiliation: Institute of Infection and Global Health and School of Veterinary Science, University of Liverpool, Liverpool, L69 7ZJ, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Baylis
authors.affiliation: Institute of Infection and Global Health and School of Veterinary Science, University of Liverpool, Liverpool, L69 7ZJ, UK.
authors.forename: Diana J L
authors.initials: DJL
authors.lastname: Williams
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000382:microbiology*; D005210:Fasciola hepatica / Q000472:pathogenicity*; D016015:Logistic Models; D014380:Tuberculosis, Bovine / Q000175:diagnosis* / Q000382:microbiology*; D006113:United Kingdom