NR AXMC
AU Fediaevsky,A.; Tongue,S.C.; Nöremark,M.; Hopp,P.
TI Atypical and Classical Scrapie in Sheep: Prevalence Estimates from Healthy Slaughter and Fallen Stock Surveillance Programmes in 20 European Countries
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Oral Abstracts FC5.6
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Vortrag
AB
Background: The introduction of extensive surveillance programmes for TSEs of small ruminants has led to the detection of a new prion disorder in sheep designated atypical scrapie. For a variety of reasons, the estimation of prevalence using published EU data was difficult. Hence it was impossible to make any valid comparisons between the prevalence of atypical and classical scrapie within and between countries.
Aims/Objectives: The aim of this work, conducted under the auspices of the NeuroPrion Network of Excellence Risk and Control Group, was to estimate the prevalence of classical and atypical scrapie within each surveillance programme in European countries. Further objectives were to compare the prevalence estimates of each scrapie-type within and between countries, within and between each surveillance programme, and to interpret the results.
Methods: A questionnaire survey was used to request relevant data from 30 European countries. Prevalence estimates for atypical scrapie (APE) were calculated as the proportion of confirmed positive atypical cases detected from all samples tested with a Bio-Rad ELISA, whilst those for classical scrapie (CPE) were calculated as the proportion confirmed positive detected from all initial tests. Binomial 95% confidence intervals were calculated and the Pearson chi-squared test used, where appropriate to test the statistical difference between proportions.
Results: Initial responses were received from 22 countries and 20 were included in the analyses. There was some evidence for variation in the CPEs with time and between surveillance programmes within a country, and within surveillance programmes between countries. In comparison, there was no evidence for variation in the APEs by country, by surveillance stream and over time within countries.
Discussion: The observed differences in CPEs are compatible with a contagious disease that occurs with varying prevalence in different countries. The similarities of the APEs between countries suggest that the aetiology and/or epidemiology of atypical scrapie differ from that of classical scrapie.
AD A. Fediaevsky, AFSSA, Epidemiology Unit, France; S.C. Tongue, CERA, VLA Weybridge, UK; M. Nöremark, SVA, National Veterinary Institute, Sweden; P. Hopp, National Veterinary Institute, Norway
SP englisch
PO Schottland