TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES

Transmissible spongiform encephalopathies are a unique group of brain diseases of different animal species and man that can be transmitted b etween individuals by inoculation or ingestion of diseased nervous sys tem tissues. The causative agents induce non inflammatory spongiform d egeneration of the central nervous system which leads to a progressive loss of brain function including ataxia and paralysis resulting alway s in death. The agent might consist only of a conformationally altered cellular protein of the host species devoid of nucleic acid. The natu ral occurance of transmissible spongiform encephalopathies is restrict ed to a few species. Thus, under certain conditions, i.e. the feeding of infectious bone meal or scientific experiments, the agents can be t ransmitted to other species causing lethal disease.