Investigation of risk factors and dynamics of bovine tuberculosis:

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Investigation of risk factors
and dynamics of bovine tuberculosis:
A cohort study in south west England
A. Ramirez-Villaescusa, L.E. Green, G.F. Medley
Ecology and Epidemiology Group, Dept. Biological Sciences,
The University of Warwick, Coventry, CV4 7AL, UK E-Mail: [email protected]
Objectives
Use the FMD 2001 outbreak as a natural experiment to
• Quantify cow to cow transmission of bovine TB within and between herds in non restocked and restocked herds
• Identify other risk factors associated with the occurrence of herd breakdown with bovine tuberculosis
Materials and Methods
Farm Selection and Study Setup
Data sources
Data obtained
VLA, Defra
TB Test Results
British Cattle Movement
Scheme (BCMS)
Animal Movement Records
• 151 farms recruited from 368 randomly selected farms
• Recruitment period: November 2002 - October 2003
• Farmers contacted by post, local meetings, telephone
• Location of farms: counties of Gloucester, Worcester, Hereford,
Somerset, Devon and Cornwall
Management
Farm Practices
Nutrition
• Herd size: from 3 to more than 500 cattle
Farmer Questionnaire
• Type of Herd: dairy, suckler, beef, mixed
• Matching criteria and farm grouping:
• 3 non-restocked (non exposed) to 1 restocked (exposed) farm
Disease Records
Veterinary Surgeon
Questionnaire
Buildings, yards,
feed stores
• between farm distance: >4Km
Building
Survey
• same treatment group as for randomised badger culling trial
• 29 groups formed
• Farmer interview, building survey and veterinary questionnaire
Future analysis
BVD, IBR, Leptospirosis,
Neospora, Johne’s Disease
Blood samples
• 10,000 blood samples from bulls and cows > 2 years old
Study Period and Progress
September
2002
1st year
September
2003
Field data collection - an example from one farm
Bloods: 10,000 samples collected
1st Year Farmer (complete)
Bloods: 1,500 samples collected to date
farm
Building survey in progress
2nd year
Veterinary Questionnaire
September
2004
3rd year
September
2005
2nd Year Farmer Questionnaire
Blood samples
Final results
Future work
Data collected will be assimilated to establish the between and within farm contact structure of cattle
The importance of cattle to cattle transmission of bovine tuberculosis and other diseases
Acknowledgements
All the participating farmers, the TB Project team: Fiona Boyd, Fiona Campbell, Juanjo Carrique-Mas, Patricia Findlay, Rod Fleming, Sian
Mercer, Alex Puddephatt, Nola Shearsby, Anna Thomas
DEFRA for funding
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