HC Deb 27 November 2001 vol 375 cc855-6W
Malcolm Bruce

To ask the Secretary of State for Environment, Food and Rural Affairs, pursuant to her answer of 16 November 2001,Official Report, column 972W, what was (a) the number of scrapie-resistant sheep that were infected with BSE over the last 12 months, (b) the proportion of sheep deemed necessary for infectivity of BSE in sheep to be confirmed and (c) the proportion of sheep that have tested positive for TSEs in the last 12 months. [17303]

Mr. Morley

[holding answer 23 November 2001]: The information is as follows:

  1. (a) Because of the long incubation period of TSEs, experiments in progress pan more than one year. There are four experiments in progress in which sheep of genotypes fully resistant to scrapie (ARR/ARR) have been challenged with BSE. 60 sheep of this genotype are being used in these experiments, along with sheep of different genotypes which are partially or fully susceptible to scrapie.
  2. (b) As the true prevalence of scrapie in sheep in the UK is unknown, various assumptions have been made to calculate how many sheep would need to be tested to determine whether BSE was present. On the assumption that the true number of scrapie cases per year is 5,000 and that 0.1 per cent. of the scrapie suspects might be BSE, the SEAC subgroup which examined surveillance requirements, and whose report was published in April 1999, estimated that 2,253 scrapie suspects would need to be tested to be certain of detecting at least one case of BSE.
  3. (c) Between November 2000 and end of September 2001, 465 sheep scrapie suspects have bene tested at VLA. 284 were found to be positive for scrapie.