Submitted to: United States Japan Natural Resources Animal and Avian Health Panel
Publication Type: Abstract Only
Publication Acceptance Date: October 5, 2010
Publication Date: N/A
Technical Abstract: Interspecies transmission studies afford the opportunity to better understand the potential host range and origins of prion diseases. Previous experiments demonstrated that white-tailed deer are susceptible to sheep-derived scrapie by intracranial inoculation. The purpose of this study was to determine susceptibility of white-tailed deer to scrapie after a natural route of exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal (1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep clinically affected with scrapie. Non-inoculated deer were maintained as negative controls. All deer were observed daily for clinical signs. Deer were euthanized and necropsied when neurologic disease was evident. One animal was euthanized 15 months post-inoculation (MPI) due to an injury. At that time, examination of brain and lymphoid tissues by immunohistochemistry (IHC) and western blot (WB) were negative. Remaining deer developed clinical signs and were necropsied from 28 to 33 MPI. Tissues from these deer were positive for scrapie by IHC and WB. Tissues with PrP**d immunoreactivity included brain and various lymphoid tissues including tonsil, retropharyngeal and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. This work demonstrates for the first time that white-tailed deer are susceptible to sheep scrapie by potential natural routes of inoculation. In-depth analysis of tissues will be done to determine similarities between scrapie in deer after intracranial and oral/intranasal inoculation and chronic wasting disease resulting from similar routes of inoculation.