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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #402010
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies

Location: Virus and Prion Research

Title: A comparison of CWD and scrapie in white-tailed deer and sheep

Author
item Greenlee, Justin
item LAMBERT, ZOE - Oak Ridge Institute For Science And Education (ORISE)
item Bian, Jifeng
item WEST GREENLEE, HEATHER - Iowa State University

Submitted to: Chronic Wasting Disease Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2023
Publication Date: 5/30/2023
Citation: Greenlee, J.J., Lambert, Z.J., Bian, J., West Greenlee, H.M. 2023. A comparison of CWD and scrapie in white-tailed deer and sheep (abstract). Chronic Wasting Disease Symposium Proceedings. 4th International Chronic Wasting Disease Symposium, May 30-June 3, 2023, Denver, Colorado.

Interpretive Summary:

Technical Abstract: The US No. 13-7 scrapie isolate has a 100% attack rate in white-tailed deer (WTD) after intracranial or oronasal challenge. Samples from the brainstems and lymph nodes of affected deer are difficult to discern from those of deer with CWD. Samples from the cerebrum or retina of WTD with scrapie retain a molecular profile similar to the original scrapie inoculum. In contrast, transmission of CWD from WTD to sheep does not readily occur. The attack rate is low after intracranial inoculation, only a single sheep had evidence of PrPSc after oronasal inoculation, and results of further passage in sheep were negative. Samples of cerebrum and brainstem from scrapie affected deer were used to assess potential transmission back to sheep after oronasal inoculation. A subset of sheep inoculated with scrapie from WTD went on to develop clinical disease. The first sheep to develop clinical signs at approximately 29 months post inoculation (MPI) were inoculated with material from the cerebrum and had the VRQ/VRQ genotype. A sheep with the ARQ/ARQ genotype also developed clinical signs, but at 48 MPI. Only a single sheep (VRQ/VRQ) inoculated with material from the deer brainstem developed clinical disease after 66 MPI. Assessment of brains from affected sheep by immunohistochemistry and stability assays indicate that the passage of scrapie through deer results in a phenotype switch: the staining characteristics and stability are different than the original No. 13-7 inoculum and similar to another strain of scrapie called x124.