Submitted to: Pig Veterinary Society International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 12, 2006
Publication Date: July 16, 2006
Citation: Greenlee, J.J., Kunkle, R.A. Nicholson, E.M., Lager, K.M., Hamir, A.N. 2006. Attempted transmission of scrapie and CWD to swine: preliminary findings. 19th International Pig Veterinary Society Congress. p. 386. Technical Abstract: Transmissible spongiform encephalopathies (TSEs) are a family of prion-associated diseases affecting several animal species and humans. Animal TSEs are acquired infections transmitted by natural routes. The pathogenesis of prion disease is highly dependent on host genotype in some species. The potential host range of a TSE can be expanded by parenteral administration of infectious inoculum into an unnatural host. A low attack rate subsequent to intracerebral (IC) inoculation is indicative of a robust species barrier to infection by a particular prion strain. There are no known naturally-occurring TSEs of swine. Swine have been exposed to ruminant specified risk materials (SRM) implicated as point sources of acquired TSEs, including SRM during the period of peak incidence of bovine spongiform encephalopathy (BSE) in the U.K. Experimentally challenged swine were found to be susceptible to BSE following parenteral inoculation, but not after oral administration of BSE-affected bovine brain. These observations indicate the existence of a strong cattle-to-pig species barrier in regards to BSE transmission. This report presents preliminary findings of planned 6-year studies to assess the potential transmissibility of sheep scrapie and chronic wasting disease (CWD) of cervids to swine. Clinical assessment and analysis of tissues collected at 6-7 months post-inoculation revealed no evidence of prion-associated disease.