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Project Name |
Spatial and temporal analysis of cattle herd breakdowns in the RBCT |
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Dates |
2008 - 2009 |
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Project Collaborators |
Fera |
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Funders |
Defra |
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Project Description
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Bovine tuberculosis caused by Mycobacterium bovis is among the greatest economic threats to the UK cattle industry. Following the recommendations of the 1997 Krebs review, the Randomised Badger Culling Trial (RBCT) was established in 1998. The trial had a simple design with 10 “triplets” of three sample areas, each of ca. 100km2, for each of three treatments comprising proactive culling of badgers, reactive culling, where badgers were removed when disease was detected in cattle, and a control with no badger removal. The RBCT confirmed that badger ecology and behaviour were critical features of the epidemiology of bovine TB within the study areas (ISG 2007). Patterns of cattle and badger disease in and around treatment areas were clearly affected by culling and these effects were explained in terms of changes in the social biology of badgers. The Independent Scientific Group concluded that whereas proactive culling reduced TB incidence in cattle within treatment areas, badger culling could lead to increased incidence of the disease in reactive culling areas and in the periphery of proactive treatment areas. This project aimed to identify sources of unexplained variability in the response of cattle herd breakdowns to badger culling treatments in the Randomised Badger Control Trial (RBCT), by taking into account the finer spatial and temporal detail of treatments and responses. We propose that Defra will gain a better understanding of the processes at work in the cattle:badger:disease system, if we address the issue at the scale of the relevant agricultural and biological processes, which is that of the farm/herd and badger social group. In this project we adopt a progressive, spatial statistical strategy that will begin by tackling uncertainty in cattle herd testing for disease, then characterising the pattern of spatial and temporal dependence in disease in badgers and cattle, before moving on to assess risk factors for disease incidence in each.
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Outputs |
Mill, A.C. Rushton, S.P. Shirley, M.D.F. Murray, A.W.A. Smith G.C. Delahay R.J and McDonald. R.A. (2011) Farm-level risk factors for bovine tuberculosis incidence in cattle herds during the Randomised Badger Culling Trial. Epidemiology and Infection. doi:10.1017/S0950268811000434 |