[Transmissible spongiform encephalopathies (TSE): old diseases with new explosive force]

Area of Science:

• Veterinary Medicine
• Neurology
• Infectious Diseases

Context:

• The emergence of Bovine Spongiform Encephalopathy (BSE) in German cattle herds necessitates a comprehensive understanding of transmissible spongiform encephalopathies (TSEs).
• The prion model, as proposed by Stanley Prusiner, provides a framework for understanding the unconventional infectious agent responsible for these diseases.

Purpose:

• To provide an overview of BSE and other TSEs, comparing their clinical, pathogenic, and pathological features.
• To explain the mechanism of prions as infectious proteins.
• To discuss knowledge on transmission, incubation periods, host specificity, resistance, and immunity based on experimental data.

Summary:

• Oral infection with prions leads to transport from the gastrointestinal tract to the spleen via lymphocytes; the pathway to the central nervous system (CNS) remains unclear.
• Cross-species transmission, such as between cattle and humans (BSE to variant Creutzfeldt-Jakob Disease - vCJD), requires biochemical homology of prions and a genetic predisposition.
• Brain, spinal cord, and lymphoid tissues are identified as the most infectious prion-containing tissues, posing significant risks.

Impact:

• Highlights the link between BSE in cattle and vCJD in humans, emphasizing the risk associated with consuming contaminated food products.
• Discusses the principles of BSE testing, its diagnostic accuracy, and outlines essential prevention and control strategies.
• Informs veterinary and public health efforts to manage and mitigate the threat of prion diseases in livestock and humans.