NR AWHB
AU Hoinville,L.J.; Tongue,S.C.; Henderson,B.; Cook,C.J.
TI Risk factors for scrapie at the individual animal level
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions EPI-07
PT Konferenz-Poster
AB Scrapie is a disease that, at a flock level, occurs at a low incidence. Many naturally-affected flocks do not experience a within-flock epidemic, however, for some individual flocks a within-flock epidemic can have a significant impact. There are still many unknowns as to mechanisms and routes of transmission, and risk factors for scrapie at the individual animal level, particularly in naturallyaffected field flocks. Over the last ten years, this study has worked with several scrapie-affected flocks in Great Britain, in an attempt to collect enough data at the individual animal level to study such risk factors. Thirty eight flocks have provided sufficient data to be included in the analyses. Descriptive analyses of individual flocks has been followed by survival analysis of cohort population data and conditional logistic regression of case control population data. Some of the results of these analyses will be presented. They include i/ confirmation that prion protein (PrP) genotype influences the occurrence of clinical scrapie, although variation in the effect of some PrP alleles is observed between flocks, ii/ evidence for maternal transmission of scrapie, but not paternal transmission, and iii/ a bimodal age distribution of scrapie cases that may be due to delayed exposure to the infectious agent in some animals. The analyses confirm the strong 'protective' effect of the ARR allele for clinical scrapie in all flocks and highlight areas for attention in the development of disease control strategies for individual flocks. This study was funded by the Department for Food and Rural Affairs.
AD Veterinary Laboratories Agency (VLA), Weybridge, Centre for Epidemiology and Risk Analysis, Addlestone, UK. E-mail: s.tongue@vla.defra.gsi.gov.uk
SP englisch
PO Italien