|
Spongiform encephalopathies
Á short literature review
K. SPENGOS
Spongiform encephalopathies or prior diseases are rare, fatal neurodegenerative diseases caused by proteinaceous infectious agents, the so-called prions. Prion molecules are extremely resistant particles. This fact should be considered both in the food preparation industry and in the sterilisation of medical instruments. The exact pathological effect of the prion protein in the nervous cells remains uncertain. Despite recent advances in the understanding of the pathogenesis and mechanisms involved, the final diagnosis can only be established neuropathologically.
The sporadic form of Creutzfeldt-Jakob disease (CJD) is the most common prion disease. Its incidence has remined stable over the years with 0,5-1 case per million of population world-wide has remained Stable over the 9 eary. There is no relation between the occurrence of the disease and the various external risk factors as well as the food chain.
In the late eighties and early nineties an outbreak of the Bovine Spongiform Encephalopathy (BSE), the so-called «mad cow disease» in the United Kingdom caused great apprehension among the European population, concerning the possibillity of human infection by the consumption of bovine nervous tissue or other animal procluts. In the late nineties a new variant of Creutzfeldt-Jakob disease (nvCJD) was described in a number of patients. There are several clinical and laboratory differences between the nvCJD and CJD. Recent studies provided powerful evidence that the causative agents of nvCJD and BSE have a common origin. The decrease of BSE in animals and nvCJD in humans following the UK ban on contaminated animal feed and consumption of affals in 1988 gives evidence that the risk of new infections in Greece today is not considerable.