A system of strong interlocking safeguards protects human and animal health, as well as food safety, in the United States. These safeguards include the removal of specified risk materials SRMs — those tissues that may contain the BSE agent in an infected animal — from the human food chain. In addition, they prevent certain slaughter practices that might present a risk of transmission of BSE. FSIS inspectors also condemn any cattle that display clinical signs of neurological disease or central nervous system disorders.
To prevent the disease's transmission to people, the single most important food safety measure is to avoid human consumption of SRMs. Inspectors in every slaughterhouse in the United States work to ensure these and other food safety standards are met. Scientific research indicates that BSE cannot be transmitted in cow's milk, even if the milk comes from a cow with BSE.
Milk and milk products, are, therefore considered safe. The primary animal-health protective measure is a feed ban. In , the FDA implemented regulations that prohibit the feeding of most mammalian proteins to ruminants, including cattle. This feed ban is the most important measure to prevent the transmission of the disease to cattle. The feed ban was strengthened in , by additional prohibitions on those tissues that have the highest risk of transmitting BSE. These additions to the feed ban prohibit the use of brain and spinal cord from cattle 30 months of age and older for use in any animal feed.
Evidence shows that our systems and safeguards to prevent BSE are very effective, as are similar actions taken by countries around the world. In , there were only 29 worldwide cases of BSE, a dramatic decline and 99 percent reduction since the peak in of 37, cases. This is directly attributable to the impact and effectiveness of feed bans as a primary control measure for the disease. BSE was first diagnosed in in Great Britain.
Since that time, more than , cases have been confirmed world-wide. The number of cases peaked in , and has declined continuously since that time, with only 29 cases worldwide in From Britain it spread to Europe, infecting over 4, cattle in 19 countries by mid The disease still kills cattle each day in Europe. In May of , a bull tested positive in Canada, and the U.
Three other cases of BSE were found in the U. McNeil Jr. House of Commons, October Mad Cow U. Maine: Common Courage Press, p. Once again mad cow disease bovine spongiform encephalopathy [BSE] has surfaced in the U. Center for Food Safety is a tax-exempt c 3 organization. Any unauthorized reprint or use of this material is prohibited. No text may be reproduced or transmitted in any form or by any means without express written permission or proper citation.
Please credit any and all use of our work product to: Center for Food Safety, www. The TSE diseases include scrapie, which affects sheep and goats; transmissible mink encephalopathy; feline cat spongiform encephalopathy; and chronic wasting disease of deer and elk. The human diseases are very rare; for example, classical CJD has been well studied and occurs sporadically worldwide at a rate of about one case per one million people each year. People with vCJD begin with serious psychiatric problems or problems with their senses ears, eyes or smell.
This first set of symptoms is followed weeks or months later by poor muscle coordination, muscle spasms, and mental confusion. The illness lasts for at least 6 months, and on average people with vCJD die approximately 13 months after their symptoms begin. When patients' brains are examined by autopsy, there are clear changes in brain tissue structure, including many "spongiform," or open spongy-looking areas, abnormal clumps of prion protein called plaques, and other areas with less prominent accumulations of abnormal prion protein.
On March 20, a statement from the Spongiform Encephalopathy Advisory Committee SEAC of the United Kingdom indicated concern that before November , when inclusion of certain cow and sheep by-products in human food was banned, the BSE agent may have been transmitted to people through contaminated food products.
The specific foods, if any that may be associated with the transmission of this agent from cattle to humans are unknown. For instance, all cases of confirmed vCJD have occurred in people who have lived in geographic areas which have had BSE cases. In addition, the time interval or "incubation period" between the most likely period for the initial exposure of the population to potentially BSE-contaminated food and onset of initial vCJD cases , about 10 years, is similar to the known time intervals between exposure to the classical CJD agent and the development of CJD.
An experimental study reported in June , showed that three cynomolgus macaque monkeys that were injected with brain tissue from cattle with BSE later developed symptoms and changes in brain tissue that were strikingly similar to vCJD Nature ; Another study published in showed that prion proteins obtained from 10 vCJD patients and BSE-infected animals had molecular characteristics that were similar to each other but distinct from prion proteins obtained from patients with classical CJD Nature ; Furthermore, results of an ongoing experimental study involving injection of a panel of various strains of mice with the agent that causes BSE and vCJD suggested that these agents cause a similar disease in mice Nature ; Histological analysis of mouse brains from this study showed no significant differences in the neuropathological changes observed in the BSE and vCJD-infected mice Neuropathology and Applied Neurobiology ; These cases have all been diagnosed since France has reported six cases.
In the UK the majority of cases of vCJD were born before , and it is very unlikely that they received vaccines contaminated with the BSE agent Vaccine ; Epidemiological evidence to date suggests that these cases of vCJD acquired the disease from eating beef products containing the BSE agent after People can get vCJD if they eat the brain or spinal cord tissue of infected cattle.
How common are mad cow disease and vCJD? What are the symptoms of vCJD? Symptoms include: Tingling, burning, or prickling in the face, hands, feet, and legs. But there are much more common illnesses that cause these same symptoms. Having tingling in parts of your body does not mean you have vCJD. Psychotic behavior. Problems moving parts of the body. As the disease gets worse, a person is no longer able to walk.
How is vCJD diagnosed? A brain biopsy is the only way to confirm a diagnosis of vCJD. How is vCJD treated? Latest Information The following health organizations are tracking and studying mad cow disease and variant Creutzfeldt-Jakob disease vCJD. Centers for Disease Control and Prevention CDC provides up-to-date information about mad cow disease and variant Creutzfeldt-Jakob disease vCJD , including tracking, prevention, travel precautions, and food inspection.
You can find information at www. Department of Agriculture USDA provides information about mad cow disease, the safety of the meat supply in the United States, and infection control guidelines.
Health Canada answers frequently asked questions about mad cow disease and vCJD and provides information about infection control and food inspection. References Citations American Red Cross
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