NR AWBI
AU Balachandran,A.V.; O'Rourke,K.I.; Spraker,T.R.; Stack,M.J.
TI Diagnosis of CWD: current situation in Canada and ongoing research projects
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre, Workshop of the Neuroprion Cervid Group - Chronic Wasting Disease (CWD): Current knowledge and European perspective 2006, 3.10.2006
PT Konferenz-Vortrag
AB Chronic wasting disease (CWD) of cervids is one of the naturally occurring animal transmissible spongiform encephalopathies (TSEs) in Canada. Since 1996, a total of 245 cases have been reported in captive elk and white-tailed deer in Saskatchewan (SK) and Alberta and in mule deer in Toronto zoo. In wild deer populations, CWD was first detected in 2000 with 103 confirmed cases to date in five focal areas in SK. During the past hunting season, 14 CWD-infected deer were detected for the first time in a location in Alberta near the SK border. The CFIA implemented a national program to eradicate CWD in 2000 and made it a Reportable Disease under the Health of Animals Act in 2001. Diagnosis and confirmation of CWD was made by several methods, including clinical signs, microscopic lesions of spongiform encephalopathy, immunoassays (immunohistochemistry-IHC, ELISA and Western blotting -WB) and electron microscopy. Histopathology, limited to the detection of spongiform lesions in brain tissues, is inadequate as a confirmatory test. IHC assay for PRPcwd deposition in brain is an approved diagnostic test for CWD and is used extensively in diagnosis and prevalence surveys. PRPcwd also accumulates in certain lymphoid tissues of deer well before neuroinvasion and the appearance of clinical signs and IHC has been proposed as a preclinical test. WB is an alternative method often more sensitive and easy to set up, hence increasingly used in reference laboratories. It also has the potential for the differential diagnosis of CWD from other animal TSEs. The development of high throughput ELISA- based rapid diagnostic tests has greatly enhanced the capacity for CWD surveillance. Since epidemiological investigations rely heavily on confirmatory tests, the standardization of methods across diagnostic and reference laboratories is critical. Susceptibility of different species of cervids and ruminants to CWD, tissue tropism and distribution of CWD prion and genetic determinants of pathogenesis are among the high priority research projects underway. The preliminary results of these studies will be presented and the implications discussed.
AD A. Balachandran: National Reference Laboratory for scrapie and CWD, Canadian Food Inspection Agency (CFIA), Ottawa, Ontario, Canada; K. O'Rourke: USDA/ARS, Pullman, WA, USA; T. Spraker: Colorado State University, Ft. Collins, CO, USA; M. Stack: VLA, Weybridge, Addlestone, Surrey,UK
SP englisch
PO Italien