NR AYIJ
AU Seuberlich,T.; Botteron,C.; Benestad,S.L.; Brunisholz,H.; Wyss,R.; Kihm,U.; Schwermer,H.; Friess,M.; Nicolier,A.; Heim,D.; Zurbriggen,A.
TI Atypical scrapie in a Swiss goat and implications for transmissible spongiform encephalopathy surveillance
QU Journal of Veterinary Diagnostic Investigation 2007 Jan; 19(1): 2-8
PT case reports; journal article; research support, non-u.s. gov't
AB Different types of transmissible spongiform encephalopathies (TSEs) affect sheep and goats. In addition to the classical form of scrapie, both species are susceptible to experimental infections with the bovine spongiform encephalopathy (BSE) agent, and in recent years atypical scrapie cases have been reported in sheep from different European countries. Atypical scrapie in sheep is characterized by distinct histopathologic lesions and molecular characteristics of the abnormal scrapie prion protein (PrPsc). Characteristics of atypical scrapie have not yet been described in detail in goats. A goat presenting features of atypical scrapie was identified in Switzerland. Although there was no difference between the molecular characteristics of PrPsc in this animal and those of atypical scrapie in sheep, differences in the distribution of histopathologic lesions and PrPsc deposition were observed. In particular the cerebellar cortex, a major site of PrPsc deposition in atypical scrapie in sheep, was found to be virtually unaffected in this goat. In contrast, severe lesions and PrPsc deposition were detected in more rostral brain structures, such as thalamus and midbrain. Two TSE screening tests and PrPsc immunohistochemistry were either negative or barely positive when applied to cerebellum and obex tissues, the target samples for TSE surveillance in sheep and goats. These findings suggest that such cases may have been missed in the past and could be overlooked in the future if sampling and testing procedures are not adapted. The epidemiological and veterinary public health implications of these atypical cases, however, are not yet known.
IN In der Schweiz wurde eine Ziege mit atypischem Scrapie entdeckt, deren PrPsc im Western blot das gleiche Muster aufwies, wie man es von atypischen Scrapie-Fällen bei Schafen kennt. Unterschiede zwischen den an atypischem Scrapie erkrankten Schafen und der Ziege fanden Seuberlich et al. aber histopathologisch hinsichtlich der Verteilung des PrPsc und der Läsionen im Gehirn. Per Immunhistochemie und mit zwei verschiedenen Schnelltests ließ sich dieses atypische Scrapie gar nicht oder kaum nachweisen. Die Autoren weisen deshalb auf das Problem der massiven Unterschätzung der tatsächlichen Anzahl atypischer Scrapie-Fälle hin, solange die Standardprozedur für die Schnelltests nicht angepasst wird.
MH Animals; Brain/pathology; Goat Diseases/*diagnosis; Goats; Immunohistochemistry; Male; Prion Diseases; Scrapie/*diagnosis
AD NeuroCenter, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, Bremgartenstrasse 109a, CH-3001 Berne, Switzerland. torsten.seuberlich@itn.unibe.ch
SP englisch
PO USA