Submitted to: American Society of Animal Science
Publication Type: Proceedings
Publication Acceptance Date: 10/30/1997
Publication Date: N/A
Technical Abstract: Transmissible spongiform encephalopathies (TSEs) are a family of neurodegenerative diseases that cause progressive disease and death in genetically susceptible animals, including humans. Disease has been recognized in humans, sheep, goats, mink, cattle, domestic cats, and several zoo bovids and feline. The diseases are caused by transformation of a normal, enzyme-sensitive protein to an enzyme resistant protein, the accumulation of which over a long period of time is directly related to disease. This change in conformation of the prion protein occurs spontaneously or may be induced by an external source of the enzyme resistant protein. Bovine spongiform encephalopathy (BSE), a member of this family has caused tremendous loss to the cattle industry in Great Britain. Most evidence indicates that BSE resulted from the feeding of contaminated protein supplement prepared from either sheep with scrapie or from cattle with smoldering undetected disease. There is considerable evidence that the BSE agent has spread to humans through consumption of contaminated tissues causing a new disease, called new variant Creutzfeldt-Jakob disease (nvCJD), of unknown epidemiological significance at this time. Diagnosis of the TSEs is difficult because of failure of the agent to induce inflammatory or immune responses and the inconclusive nature of the clinical signs. Diagnosis is generally made at post mortem by examining the brain microscopically for lesions, often aided by the use of immunoassay of the brain for the causal agent. There is no test for the disease in live animals.