Bovine spongiform encephalopathy.
نویسندگان
چکیده
Early epidemiological studies identified bovine spongiform encephalopathy as a feed-borne infection associated with infected meat-and-bone meal in animal feed. The infection may have derived from scrapie in sheep, a spontaneous genetic mutation in cattle, or a transmissible spongiform encephalopathy in another mammalian species. Experimental work on the risk of transmission has necessarily tried to identify risk materials and their infectivity levels, the nature and size of species barriers, the infectious dose, the route of infection, the strain of the agent and the genotype of the animals at risk. The identification of levels of infection in cattle tissues has aided the removal of risk materials from the human and animal food chains. Maternally associated transmission is unlikely to maintain an outbreak, but the offspring of clinical cases appear to be at greater risk when the rate of food-borne exposure is high. Studies of embryo transfer have not shown infection to be transmitted by this means. While the control measures appeared to be straightforward, compliance has at times proved difficult to enforce and quantify. This has necessitated more extensive prohibitions, aggressive enforcement and thorough auditing of compliance levels.
منابع مشابه
Bovine spongiform encephalopathy.
A detailed account is given of the occurrence of bovine spongiform encephalopathy (BSE), current research into the aetiology of this new disease of cattle, and the relationship between BSE, scrapie and other similar diseases. Epidemiology, clinical signs, pathology, diagnosis, prevention and control are described.
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We report transmission of atypical L-type bovine spongiform encephalopathy to mouse lemurs after oral or intracerebral inoculation with infected bovine brain tissue. After neurologic symptoms appeared, transmissibility of the disease by both inoculation routes was confirmed by detection of disease-associated prion protein in samples of brain tissue.
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BACKGROUND Public health and agricultural policy attempts to keep bovine spongiform encephalopathy out of North America using infectious disease containment policies. Inconsistencies of the infectious disease model as it applies to the spongiform encephalopathies may result in failure of these policies. METHODS Review of historical, political and scientific literature to determine the appropr...
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Sheep CH1641-like transmissible spongiform encephalopathy isolates have shown molecular similarities to bovine spongiform encephalopathy (BSE) isolates. We report that the prion protein PrPSc from sheep BSE is extremely resistant to denaturation. This feature, combined with the N-terminal PrPSc cleavage, allowed differentiation of classical scrapie, including CH1641-like, from natural goat BSE ...
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Since the BM7's last editorial on the topic' another 40 000 cases of bovine spongiform encephalopathy have been confirmed in cattle. New cases are being confirmed at the rate of 500 a week. Does it matter that between 1986 and 1989 we actually had the offal, which is now proscribed, going into the food chain?2 Several reasons are given for dismissing bovine spongiform encephalopathy as carrying...
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عنوان ژورنال:
- Pathologie-biologie
دوره 43 2 شماره
صفحات -
تاریخ انتشار 1990