Scrapie Surveillance in Great Britain

The results of the largest ever scrapie surveillance programme in Great Britain have been published today. More than 50,000 older sheep slaughtered in abattoirs were tested for scrapie and genotyped during the programme.

The main findings are both that scrapie incidence is around that expected and there are some contradictory results which need further discussion and work by relevant experts.

The major new #9m survey provides a wealth of new information about scrapie in GB, helping Defra and the devolved administrations to estimate reliably the prevalence of scrapie .

The results show that the level of scrapie remains at around the level of previous estimates. They show that the prevalence of infection in the GB sheep population is 0.33 per cent. Earlier results, based on fewer sheep and less advanced diagnostic methods, gave an estimated prevalence of 0.22 per cent, but this is not evidence for an increase in the prevalence of infected animals.

The Government is committed to working with industry to reduce the incidence of scrapie through the National Scrapie Plan.

The survey had two parts. The Veterinary Laboratories Agency used different tests on some samples and also tested samples of tonsil and lymph nodes as well as brain for some sheep. Different estimates of prevalence were obtained depending on the tissues tested.

The survey also found in the case of a small number of samples that different tests produced different results. In 28 cases, results were positive using one test but negative using another. Eight of these were from sheep of the genotype usually associated with scrapie resistance. Both the Spongiform Encephalopathy Advisory Committee and the Food Standards Agency are aware of these findings and an expert scientific group is being established to look into them. There will also need to be discussions at EU level.