M03027: How much sheep-TSE infectivity enters the human food chain? An assessment of risk reduction by removal of scrapie flocks
Thursday 9 October 2003
This research project aims to estimate the reduction in theoretical risk to the consumer if sheep from scrapie-infected flocks were removed from the food chain.
Background
There is concern that scrapie in sheep has the potential to mask the presence of BSE in this species. TSEs in sheep are known to affect a wide range of tissues. This coupled with the long history of scrapie in sheep suggests that the epidemic must be maintained by the spread of the disease from sheep to sheep, not just via consumption of contaminated feed. The report of the FSA core stakeholder group on BSE and sheep considered a number of measures that could be taken to reduce the theoretical risk from the consumption of sheep meat. This project is a risk analysis to determine the reduction in the risk to the consumer that would be achieved by eliminating from the food chain, all sheep in flocks with established scrapie infection.
Research Approach
TSE infectivity entering the human food chain is the measured outcome. Mathematical models will be used to compare the impact of different culling strategies. The study will use data from scrapie postal surveys, the large-scale farm-based scrapie study at Compton and other appropriate data sources. The epidemiology of scrapie in British sheep flocks is now well understood but there is very little known about the spread of BSE in sheep. For this reason, the risk assessment will consider scrapie and BSE separately.