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A quantitative risk assessment on the role of wild deer in the perpetuation of TB in cattle - SE3036
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Description
Bovine TB is a serious disease in cattle in Britain. While the badger is considered the primary wildlife reservoir recent research at the Central Science Laboratory (CSL) has identified four species of wild deer infected with the disease. Two of these (red and fallow deer) were qualified as posing a potentially high risk to cattle, based on the prevalence of the disease amongst carcasses sampled and the behavioural ecology of these species.
The proposed project aims to produce a quantified risk assessment of the role of wild deer in perpetuating TB in cattle. We propose to use a comparative approach, using risks posed by badgers as a benchmark against which to assess the role of deer. This is considered essential due to the large number of knowledge gaps and high degree of uncertainty surrounding transmission of TB between and to cattle and deer.
Current published literature and unpublished reports will provide data to populate the model. Data deficiencies will be overcome using expert opinion from within and outside CSL. Parameters will include assessment of uncertainty and variability to provide confidence bounds to the final assessment of risk for each deer species. Knowledge gaps will be identified and prioritised for future research.
We propose an optional bolt-on study* to quantify direct and indirect contact between cattle and deer and their excretory products. Excretory products are alleged to provide a key source of TB transmission between badgers and cattle. Direct observation of deer and cattle interacting at pasture and measurement of the spatio-temporal position of deer dung and cattle dung at pasture will provide novel estimates of contact rates to populate the risk assessment model.
Information from the proposed project will improve our understanding of the likely role of deer in perpetuating TB in cattle and will thus aid DEFRA to further develop informed policy options for controlling TB in cattle. |
Objective
1) Quantification of the overall risk of M. bovis infection in cattle posed by each species of deer and badgers independently and together.
2) Quantification of relative contributions of each potential transmission route for each species of deer and badgers to the overall risk of cattle M. bovis infection.
3) Identification of knowledge gaps limiting the precision of risk assessment.
In order to address these we will answer the following questions:
a) What do we know about TB prevalence, pathology and transmission in British deer and badgers?
b) What do we know about TB in ungulates in other countries?
c) What aspects of deer and badger behaviour and ecology could influence the maintenance and spread of TB within deer herds of each species and between deer, badgers and cattle?
d) What are the likely key risk areas to cattle caused by deer and badger behaviour and ecology?
e) How is each deer species distributed in the south west of England?
f) What are the abundance patterns of each deer species across the south west of England?
g) For areas where we have data on TB prevalence and spoligotype for deer are these the same for cattle?
h) What gaps exist in our current knowledge which increase the uncertainty associated with our quantified risk assessment of risks posed by deer and badgers to cattle, which of these gaps should be addressed and how?
i) What risks do tuberculous deer pose to human health, including stalkers, farmers and other countryside users?
An optional bolt-on project is also proposed:
4) Empirical quantification of deer behaviour contributing to direct and indirect deer-cattle contact rates in space and time.
j) What behaviours bring deer into direct and indirect contact with cattle?k) Do these behaviours vary between species
l) With what frequency do deer come into direct and indirect contact with cattle?
m) What are the likely key spatio-temporal locations for direct and/or indirect contact between deer and cattle and how do these influence the risk assessment? |
Project Documents
• Final Report : A quantitative risk assessment on the role of wild deer in the perpetuation of TB in cattle
(1103k)
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Time-Scale and Cost
From:
2005
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To:
2006
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Cost: £146,656 |
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Contractor / Funded Organisations
Central Science Laboratory |
Keywords
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Fields of Study and Contacts
Animal Health - vetscience@defra.gsi.gov.uk |