NR AWBD
AU Arnold,M.E.; Ryan,J.B.M.; Konold,T.; Simmons,M.M.; Spencer,Y.I.; Wear,A.; Chaplin,M.J.; Stack,M.J.; Szub,S.; Mueller,R.; Webb,P.R.; Davis,A.; Spiropoulos,J.; Holdaway,J.; Hawkins,S.A.C.; Austin,A.R.; Hills,R.; Rogers,R.; Wells,G.A.H.
TI Estimating the temporal relationship between PrPsc detection and incubation period in experimental bovine spongiform encephalopathy (BSE) of cattle
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions RA-01
PT Konferenz-Poster
AB The age of cattle at which central nervous system (CNS) and associated structures should be removed at slaughter to protect human and animal health from exposure to BSE infection cannot be accurately determined based on current data. This study addresses the detection of disease specific PrP (PrPsc) relative to time after exposure in CNS and certain peripheral nervous system ganglia tissues, from cattle dosed with 100g or 1g of BSE infected brain and then killed sequentially throughout the disease course, using immunohistochemical labelling, a Western blot incorporating a sodium phosphotungstic acid precipitation step (WBNaPTA) and BioRadTeSeE, diagnostic methods. Data from experimental studies of attack rate and dose/incubation period response for the doses were obtained from experimental attack rate studies. The development of a statistical model accounted for the differences in incubation period and probability of infection between the different dose groups. There was little overall difference in the timing of detection of PrPsc among different CNS tissues, although immunohistochemistry detected PrPsc in the medulla oblongata (the current statutory testing target site) earlier than the other two testing modalities. There was a significant difference in the estimated timing of detection relative to incubation period, according to dose; the point at which 50 percent of the animals would be detected by immunohistochemistry applied to rostral medulla was estimated to occur at 1.7 months and 9.6 months before onset of clinical signs for the 1g and 100g dosed cattle respectively. There was a very low probability of detection in any of the tissues, by any of the tests, at more than 12 months before clinical onset. PrPsc was inconsistently detected in dorsal root ganglia and not at all in certain sympathetic nervous system ganglia associated with the vertebral column. When dorsal root ganglia were positive, detection was always after the CNS was positive.
AD M.E. Arnold, J.B.M. Ryan, T. Konold, M.M. Simmons, Y.I. Spencer, A. Wear, M. Chaplin, M. Stack, P.R. Webb, A. Davis, J. Spiropoulos, J. Holdaway, S.A.C. Hawkins, A.R. Austin, G.A.H. Wells: Veterinary Laboratories Agency, Woodham Lane, New Haw, Addleston, Surrey, KT15 3NB, UK; S. Czub: Canadian Food Inspection Agency, Winnipeg, Manitoba, R3E 3M4, CA; R. Mueller, R. Hills, R. Rogers: Health Canada, Tunney's Pasture, Ottawa, Ontario, K1A 0K9, CA
SP englisch
PO Italien