Rion Diseases and Blood Transfusion

Abstract

The transmissible spongiform encephalopathies (TSE ) comprise a spectrum of diseases in animals and man. Scrapie was first described over 200 years ago and is endemic in sheep and goats throughout large parts of the world. There is no evidence, however, that it has ever transmitted to man. Chronic Wasting Disease is endemic in Rocky Mountain Elk and Mule Deer in the USA and again there is no direct good evidence that it is transmissible to man. Transmissible Mink Encephalopathy (TME ) described in farmed mink in Wisconsin, may have been transmitted via contaminated food. Bovine Spongiform Encephalopathy (BSE ) was first described in the United Kingdom in 1985. Infected cattle display characteristic clinical features in which they become hypersensitive, ataxic and difficult to handle, hence giving rise to the colloquial name “Mad Cow Disease”. It is thought that the disease either arose spontaneously in cattle or was transmitted from scrapie infected sheep, and was thereafter propagated via rendered meat and bone meal products. More than 180,000 clinical cases of BSE have been described to date in the UK, and although the incidence of the disease continues to decline, 1,300 further cases were described in 2000. It is thought that up to another 750,000 cases of BSE could have entered the human food chain prior to the development of clinical disease. About 1,500 cases of BSE have been described in other European countries thus far. Natural and experimental transmission of BSE has occurred in up to twenty different species including domestic and exotic cats and exotic ungulates in British zoos.