NR ATLA
AU Stack,M.J.; Jeffrey,M.J.; Gubbins,S.
TI Monitoring for bovine spongiform encephalopathy in sheep in Great Britain, 1998-2004
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Diagnosis DIA-38
PT Konferenz-Poster
AB
BSE may have transmitted to British sheep via contaminated feed in the 1980s. New strain typing techniques based on immunohistochemical (IHC) detection of abnormal prion protein (PrPd) and the molecular analysis of proteinase-resistant protein (PrPres), by Western blotting (WB) can discriminate between natural or experimental scrapie and experimental BSE in sheep.
Between 1st January 1998 and 31st May 2004, 2368 sheep, clinically suspected of scrapie, were found positive for a transmissible spongiform encephalopathy (TSE) by statutory testing in Great Britain. Brain tissue from these cases was tested using these new discriminatory methods. Fourteen brain samples showed PrPres WB patterns that were unlike those found in natural or experimental scrapie.
Two in particular gave WB results that were similar to those obtained with experimental BSE in sheep. However, when all 14 were tested by IHC, no match to experimental BSE in sheep results could be found.
On the samples available, our results provide no evidence for the presence of BSE in sheep. Epidemiological interpretation of individual cases indicates that up to 0.14 % of sheep TSE cases could be BSE. A more conservative estimate for the sample size is the number of flocks tested, in which case, the maximum proportion increases to 0.66 %. These estimates are lower than previously calculated when the analysis was based on the results of strain typing in mice (2 % and 5 %, respectively). Continued screening and further in depth examination of unusual cases by discriminatory methods will enable updated BSE in sheep predictions to be made.
IN In Großbritannien wurden zwischen dem 1.1.1998 und dem 31.5.2004 unter klinisch verdächtigen Schafen 2.368 als Scrapie-positiv diagnostiziert. Davon zeigten 14 im Western blot auffällige Bandenmuster, zwei sogar große Ähnlichkeit mit den Bandenmustern BSE-infizierter Schafe. Immunhistochemisch sah jedoch kein einziger britischer Scrapie-Fall so aus, wie man es von experimentell mit BSE infizierten Schafen kennt. Sollte es BSE-infizierte britische Schafe geben, dann dürfte ihr Anteil an den britischen Scrapie-Fällen demnach unter 1% liegen.
AD Michael Stack, Veterinary Laboratories Agency, Weybridge UK; Martin J. Jeffrey, Veterinary Laboratories Agency Lasswade, Scotland; Simon Gubbins, Institute for Animal Health, Compton- Newbury, Berkshire
SP englisch
PO Deutschland