About Bovine Spongiform Encephalopathy (Mad Cow Disease)
Learn about the disease, illness and/or condition Bovine Spongiform Encephalopathy (Mad Cow Disease) including: symptoms, causes, treatments, contraindications and conditions at ClusterMed.info.
Bovine Spongiform Encephalopathy (Mad Cow Disease)
Bovine Spongiform Encephalopathy (Mad Cow Disease) |
---|
Bovine Spongiform Encephalopathy (Mad Cow Disease) InformationAbout BSEBSE (bovine spongiform encephalopathy) is a progressive neurological disorder of cattle that results from infection by an unusual transmissible agent called a prion. The nature of the transmissible agent is not well understood. Currently, the most accepted theory is that the agent is a modified form of a normal protein known as prion protein. For reasons that are not yet understood, the normal prion protein changes into a pathogenic (harmful) form that then damages the central nervous system of cattle.Research indicates that the first probable infections of BSE in cows occurred during the 1970's with two cases of BSE being identified in 1986. BSE possibly originated as a result of feeding cattle meat-and-bone meal that contained BSE-infected products from a spontaneously occurring case of BSE or scrapie-infected sheep products. Scrapie is a prion disease of sheep. There is strong evidence and general agreement that the outbreak was then amplified and spread throughout the United Kingdom cattle industry by feeding rendered, prion-infected, bovine meat-and-bone meal to young calves.The BSE epizootic in the United Kingdom peaked in January 1993 at almost 1,000 new cases per week. Over the next 17 years, the annual numbers of BSE cases has dropped sharply; 14,562 cases in 1995, 1,443 in 2000, 225 in 2005 and 11 cases in 2010. Cumulatively, through the end of 2010, more than 184,500 cases of BSE had been confirmed in the United Kingdom alone in more than 35,000 herds.There exists strong epidemiologic and laboratory evidence for a causal association between a new human prion disease called variant Creutzfeldt-Jakob disease (vCJD) that was first reported from the United Kingdom in 1996 and the BSE outbreak in cattle. The interval between the most likely period for the initial extended exposure of the population to potentially BSE-contaminated food (1984-1986) and the onset of initial variant CJD cases (1994-1996) is consistent with known incubation periods for the human forms of prion disease.Overview of BSE in North AmericaThrough February 2015, BSE surveillance has identified 24 cases in North America: 4 BSE cases in the United States and 20 in Canada. Of the 4 cases identified in the United States, one was born in Canada; of the 20 cases identified in Canada, one was imported from the United Kingdom (see figure above). BSE Cases Identified in Canadian-born CattleAs of February 18, 2015, 20 BSE cases in Canadian-born cattle have been identified, 19 in Canada and 1 in the U.S. Of these 20 cases, 14 were known to have been born after the implementation of the 1997 Canadian feed ban ; 13 of these 14 were born after March 1, 1999. (See Figure above: BSE Cases in North America, by Year and Country of Death, 1993-02/2015). This latter date is particularly relevant to the U.S. because since a USDA rule went into effect on November 19, 2007, Canadian cattle born on or after March 1, 1999 have been legally imported into this country for any use. One of the 20 Canadian-born BSE cases was reported in an animal that was most likely born before or possibly very shortly after implementation of the 1997 feed ban. Based on the known or most likely year of birth, an average of 1.4 cases of BSE occurred among the group of animals born each year in Canada from 1991 through 2004. The highest reported number of cases by birth year in a single year, 3 BSE cases, occurred in 2000, 2001 and 2002. The most recently reported case extends the period of BSE transmission in Canada through at least the early half of 2009. BSE Cases Identified in the United StatesThere have been 4 cases of BSE identified in the United States. The following information provides descriptions of these 4 cases:
BSE PrevalenceBased on World Organization of Animal Health (OIE) standards for BSE surveillance, the reported national prevalence rates of BSE in North American cattle, particularly in animals born in the United States, is very low, and therefore, difficult to measure accurately. In September 2007, the USDA published updated results of the two statistical models used by Harvard University investigators to estimate the prevalence of BSE in Canada. The results incorporated the 11 Canadian-born animals with BSE that had been reported at that time. A key advantage of these models is that they provide statistical confidence limits that measure some of the uncertainty associated with expected estimates. This model estimated that the true prevalence of BSE in Canada has been 90% likely to be between 18-fold and 48-fold higher than the previously published best estimate of the prevalence of BSE in the United States (3.0 to 8.0 cases per million in Canada compared to a best estimate of 0.167 cases per million in the United States). The previously published best estimate of Canada's BSE prevalence in 2006 using the BSurveE model was 23-fold higher than that of the United States and is the estimate of the BSE prevalence in Canada that continues to be used in the Harvard Risk Assessments' "worst case" analyses when evaluating the risk of imported Canadian cattle causing BSE to spread among U.S. animals. Feed BansAs of October 26, 2009, a regulation issued by FDA in April 2009 came into effect establishing an enhanced BSE-related feed ban in the United States. This enhanced ban will further harmonize BSE feed control measures in the U.S. with those in Canada (see below). In addition, FDA continues to enforce its important 1997 mammalian-to-ruminant feed ban through its BSE inspection and BSE feed testing programs.As of July 12, 2007, an enhanced BSE-related feed ban came into effect in Canada. CFIA established this ban to more effectively prevent and quickly eliminate BSE from Canada. The enhanced ban prohibits most proteins, including potentially BSE infectious tissues known as "specified risk materials" (SRM) from all animal feeds, pet foods, and fertilizers, not just from cattle feed as required by the ban instituted in 1997. The 1997 feed ban in Canada was similar to the feed ban instituted in the United States that same year. As recently reported by CFIA, removing SRM from the entire animal feed system addresses risks associated with the potential contamination of cattle feed during production, distribution, storage, and use. Applying the same measure to pet food and fertilizer materials addresses the possible exposure of cattle and other susceptible animals to these products. CFIA expects that with this new ban, BSE should be eliminated from the Canadian cattle herd by about the year 2017.The Canadian-born cow confirmed to be infected with BSE in 2015 illustrates the difficulty in determining the effectiveness of previously instituted feed bans to prevent BSE transmissions. The initial feed bans established in both the United States and Canada were instituted in 1997. After an assessment by USDA and its Canadian counterparts, the Canadian feed ban was judged to be fully effectiveness as of March 1999. However, largely because of recognized limitations of this ban and the ban established in the United States, new, enhanced feed bans went into effect in Canada, July 12, 2007, and in the U.S., October 26, 2009. While USDA has confirmed no U.S.-born cattle as having a classic form of BSE, Canadian cattle born after March 1999 have been legally imported into the United States for any purpose since November 19, 2007. Mad cow disease facts*Mad cow disease facts medically edited by Charles Patrick Davis, MD, PhD
Strains of BSEThere is increasing evidence that there are different strains of BSE: the typical BSE strain responsible for the outbreak in the United Kingdom and two atypical strains (H and L strains).
|
More Diseases
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
Diseases & Illnesses Definitions Of The Day
- Fluid on the Lungs (Pleural Effusion (Fluid In the Chest or On Lung)) ‐ Can pleural effusion be prevented?, How is pleural effusion diagnosed? …
- Bladder Cancer ‐ Bladder cancer facts, Can bladder cancer be prevented?, How is bladder cancer diagnosed? …
- EMG (Electromyogram) ‐ How do you prepare for an intramuscular EMG?, How is an intramuscular EMG done? …
- Diffuse Astrocytomas (Adult Brain Tumors) ‐ Brain and spinal cord biopsy, Brain and spinal cord tumor in adults definition and facts* …
- Tear In the Aorta (Aortic Dissection) ‐ Aortic dissection facts, Can aortic dissection be prevented? …
- Cataplexy (Narcolepsy) ‐ Can narcolepsy be cured?, For more information on narcolepsy …
- Allergy, Latex (Latex Allergy) ‐ How do health-care professionals assess and diagnose a latex allergy? …
- Infectious Brain Lesions (Brain Lesions (Lesions on the Brain)) ‐ Brain anatomy, Brain lesions facts, Can brain lesions be prevented? …
- Preventing a Stroke (Stroke Prevention) ‐ Do You Know Your Stroke Risk?, Introduction, What are Risk Factors for a Stroke? …
- Vulvodynia (Vaginal Pain (Vulvodynia)) ‐ Home remedies for vaginal pain and vulvodynia, How is vaginal pain and vulvodynia diagnosed? …