NR AORV
AU Dexter,G.; Ryder,S.J.; Tongue,S.; Bellworthy,S.J.
TI The study of lateral transmission of Natural Scrapie between sheep kept under natural conditions using lymphoid tissue biopsy
QU International Conference - Prion diseases: from basic research to intervention concepts - TSE-Forum, 08.10.-10.10.2003, Gasteig, München - Poster session - PG-05
PT Konferenz-Poster
AB
Scrapie, an invariably fatal nervous disease of sheep, is known to transmit between sheep under natural conditions. It was originally thought to be transmitted maternally due to the high risk of lambs becoming infected if born to affected ewes. Subsequent research has shown that genetic susceptibility is transmitted from dam to lamb, but it is believed that risk of tranmsission of infection is increased during the lambing period when ewes are housed in close proximity of each other.
This study used detection of disease specific PrPsc in the tonsilar and 3rd eyelid lymphoid tissue to detect infection in sheep kept under normal farm conditions, but in a flock specifically maintained to maximise Scrapie infection.
In this flock native born lambs of the most susceptible genotype show highly efficient transmission; all lambs succumb with age at death of less than two years.
Scrapie free ewes of highly susceptible genotypes were introduced to the flock at various ages and allowed to lamb with the flock. These ewes have become infected as demonstrated by biopsy of lymphoid tissues. Lambs born to ewes newly introduced became infected and succumbed to Scrapie with the same incubation period as those born to infected ewes.
It is concluded that lateral transmission occurs between adults and between adults and young sheep and that maternal transmission, if it occurs at all, does not contribute significantly to the pattern of infection seen in this high incidence flock.
AD
Glenda Dexter, Stephan J. Ryder, Susan Tongue, Susan J. Bellworthy, Veterinary Laboratory Agency Weybridge, Woodham Lane, New Haw, Addlestone, Surrey , UK
SP englisch
PO Deutschland