NR AOZE
AU Siso,S.; Botteron,C.; Doherr,M.G.; Zurbriggen,A.; Vandevelde,M.
TI Neuropathological Evidence for a Subclinical State of BSE?
QU International Conference - Prion diseases: from basic research to intervention concepts - TSE-Forum, 08.10.-10.10.2003, Gasteig, München - Poster session - PG-21
PT Konferenz-Poster
AB
The ongoing BSE epidemic and its link to variant CJD in man highlight the need for effective BSE surveillance schemes. Prion diseases are neuropathologically characterised by vacuolation, neuronal loss and astrocytosis in specific regions of the central nervous system (CNS). Resistant prion protein (PrPres) deposition is currently used as the disease marker in standard and rapid diagnostic tests. However, both histopathological lesions and PrPres deposition have been demonstrated in the CNS of cattle without reported clinical (neurological) signs. Studies addressing the link between clinical status and lesion profile performed up to date are inconclusive, and the existence of a true subclinical disease status in cattle has been discussed.
In Switzerland, since 1999 all clinical BSE suspects, all adult emergency-slaughtered cattle and all fallen stock are examined for BSE. Independently, a sample of healthy-slaughtered cattle over 30 months was tested. All rapid-test positive samples were further confirmed by histology and immunohistochemistry. Information on the clinical symptoms of all positive cases, regardless of their surveillance category, was retrieved retrospectively.
The aim of this study was to compare PrPres and vacuolation scores in several target nuclei in the obex region between BSE cows from the different surveillance categories to address the question whether a subclinical state of BSE is likely to exist.
Preliminary results on 125 cases demonstrated that vacuolation scores are well correlated between different target nuclei within the same animals, but scores differ significantly between animals from different surveillance categories. Similar findings were made for the PrPres scores. In a next step, the cattle classification will be modified by the results of the questionnaire on disease history, and additional cattle will be included in the study. So far, however, there is no evidence to suggest the existence of a true subclinical state of BSE.
AD Silvia Sisó, Catherine Botteron, Marcus G. Doherr, Andreas Zurbriggen, Marc Vandevelde, NeuroCenter, Dept. Clinical Vet. Med., Bern University, Switzerland
SP englisch
PO Deutschland