What is "Mad Cow Disease" (Bovine Spongiform Encephalopathy/BSE)?
Mad Cow Disease is the commonly used name for Bovine Spongiform Encephalopathy (BSE), a slowly progressive, degenerative, fatal disease affecting the central nervous system of adult cattle. Since 1990, the U.S. Department of Agriculture (USDA) has conducted aggressive surveillance of the highest risk cattle going to slaughter in the United States.
What causes BSE?
The exact cause of BSE is not known but it is generally accepted by the scientific community that the likely cause is infectious forms of a type of protein, prions, normally found in animals cause BSE. In cattle with BSE, these abnormal prions initially occur in the small intestines and tonsils, and are found in central nervous tissues, such as the brain and spinal cord, and other tissues of infected animals experiencing later stages of the disease.
Was a second case of BSE identified in the U.S. in June 2005?
Yes, the USDA surveillance program identified the second BSE case in the U.S. This cow was originally identified in November 2004. Results from this animal were inconclusive in screening tests, but negative in confirmatory immunohistochemical tests. USDA recently conducted an additional confirmatory test, Western Blot, and the results were positive for BSE. USDA sent the samples to the Weybridge, UK lab where BSE was confirmed. An epidemiological investigation to trace the origins of the cow is underway. USDA confirms that the cow was born before the U.S. instituted its ban on the use of most mammalian protein in feed for ruminant animals-believed to be the most critical protective measure in preventing the spread of BSE among cattle.
Did meat and meat products from the June 2005 cow enter the food supply?
No, the cow was presented at slaughter as non-ambulatory (a downer). Therefore, in accordance with BSE regulations established by USDA and FDA the material from the animal did not enter the human food supply.
Was a case of BSE identified in the U.S. in December 2003?
Yes, the USDA surveillance program identified the first BSE case in the U.S. in a dairy cow in Washington State. The cow was bought from a farm in Canada.
Did meat and meat products from the 2003 BSE cow enter the food supply?
As soon as the BSE case was identified, both USDA and FDA activated their BSE Emergency Response Plans, and USDA immediately recalled the meat. Meat that did enter the food supply was quickly traced and was removed from the marketplace. Moreover, all the organs in which infectious prions occur were removed at slaughter and did not enter the food supply. Consumers should feel very confident that the system of multiple firewalls maintained by Federal agencies protects them from possible exposure to BSE. In addition, we believe it is important for consumers to also understand that scientific research indicates that muscle meat is not a source of infectious prions.
Will there be additional cases?
In 1998, USDA commissioned the Harvard Center for Risk Analysis to conduct an analysis and evaluation of the U.S. regulatory measures to prevent the spread of BSE in the U.S. and to reduce the potential exposure of U.S. consumers to BSE. The Harvard study concluded that, if introduced, due to the preventive measures currently in place in the U.S., BSE is extremely unlikely to become established in the United States.
FDA and other Federal agencies have been vigilant in strengthening protective measures to reduce the U.S. consumer's risk of exposure to BSE-contaminated food and cosmetic products. Since 1989, USDA has banned imports of live ruminants, such as cattle, sheep and goats, and most products from these animals from countries known to have BSE. Subsequently, USDA expanded this ban to include both countries with BSE and countries at risk for BSE. In 1997, FDA prohibited, with some exceptions, the use of protein derived from mammalian tissues in animal feed intended for cows and other ruminants. See the FDA/CVM website at www.fda.gov/cvm for information on the "ruminant feed ban."
On Jan. 8, 2004, the USDA's Food Safety and Inspection Service issued new rules to enhance safeguards against BSE. Details on these rules may be found at USDA's website, www.usda.gov. Also in 2004, FDA issued a rule that prohibits the use of certain cattle material, because of the risk of BSE, in human food and cosmetics.
Does BSE affect people?
There is a disease similar to BSE called Creutzfeldt-Jacob Disease (CJD) that is found in people. A variant form of CJD (vCJD) is believed to be caused by eating contaminated beef products from BSE-affected cattle. To date, there have been 155 confirmed and probable cases of vCJD worldwide among the hundreds of thousands of people that may have consumed BSE-contaminated beef products. The one reported case of vCJD in the United States was in a young woman who contracted the disease while residing in the UK and developed symptoms after moving to the U.S.
What measures are being taken to ensure food safety in the U.S. from BSE?
Since 1989, the FDA and other federal agencies have had ongoing regulatory measures in place to prevent BSE contamination of U.S. food and food products. Following the identification in a Washington state dairy herd of a BSE-positive cow imported from Canada, USDA issued new regulations containing additional safeguards to further minimize risk for introduction of the BSE agent into the U.S. food supply. See USDA's website www.usda.gov for further information.
Similarly, FDA has prohibited the use of the cattle materials that carry the highest risk of BSE in human food, including dietary supplements, and in cosmetics. FDA's rule (and September 2005 amendments) prohibit use of the following cattle material in human food and cosmetics:
- a. cattle material from non-ambulatory, disabled cattle,
b. cattle material from organs from cattle 30 months of age or older in which infectious prions are most likely to occur, and the tonsils and the distal ileum of the small intestine of cattle of all ages,
c. cattle material from mechanically separated (MS) (beef), and
d. cattle material from cattle that are not inspected and passed for human consumption
FDA's rule also requires that food and cosmetics manufacturers and processors make available to FDA any existing records relevant to their compliance with these prohibitions. FDA has also published a proposal requiring manufacturers and processors of food and cosmetics made with cattle material to establish and maintain records demonstrating that their products do not contain prohibited cattle material.
In September 2005, FDA amended the interim final rule to allow use of the small intestine in human food and cosmetics, provided the distal ileum has been removed. FDA also clarified that milk and milk products, hide and hide-derived products and tallow derivatives are not considered prohibited cattle materials. Finally, in response to comments the agency has reconsidered the method cited in the interim final rule for determining insoluble impurities in tallow and is citing a method that is less costly and requires less specialized equipment.
Are the protective measures in place sufficient to ensure the safety of the human food supply in light of the June 2005 BSE positive cow?
Yes, the protective measures put into place in July 2004 by FDA ensure that cattle materials that carry the highest risk of transmitting the agent that causes BSE are excluded from human food, including dietary supplements, and cosmetics. These measures, along with similar measures established by USDA, provide a uniform national BSE policy and ensure the safety of human food.
Is the food in the U.S. likely to be a BSE risk to consumers?
FDA and other federal agencies have had preventive measures in place to reduce the U.S. consumer's risk of exposure to any BSE-contaminated meat and food products. Since 1989, USDA has prohibited the importation of live animals and animal products from BSE-positive countries. Subsequently, USDA expanded the ban to include both countries with BSE and countries at risk for BSE. Since 1997, FDA has prohibited the use of most mammalian protein in the manufacture of ruminant feed. In 2004, FDA issued a rule prohibiting the use of certain cattle materials in human food and cosmetics, and USDA issued a rule prohibiting certain cattle materials from use as human food.
Is cow's milk a source of BSE?
Scientific research indicates that BSE is not transmitted in cow's milk, even if the milk comes from a cow with BSE. Milk and milk products, even in countries with a high incidence of BSE are, therefore, considered safe.
Can milk be infected with BSE from a BSE-positive cow?
No detectable infectivity in cow's milk has been reported from any BSE-infected cows. Infectious prions have not been detected by bioassay of milk from cattle with BSE.
Does the use of bovine-derived ingredients in dietary supplements mean that they are not safe?
No. The requirements that FDA has in place should give consumers confidence that their food, including dietary supplements, is safe. Most recently, FDA published a rule that prohibits the use in human food, including dietary supplements, of the cattle materials that have the highest risk of harboring BSE infectivity. The rule applies to both imported and domestic dietary supplements and their ingredients. Furthermore, most ingredients used to produce dietary supplements and most other food ingredients come from cattle that are slaughtered when they are less than 30-months of age and, because of their age, present little risk of being BSE-positive. It is not a common occurrence for animals younger than 30 months to develop BSE.
Since the BSE-positive cows were discovered in the U.S., does that mean that dietary supplements made with domestic ingredients might be unsafe?
No. The requirements that FDA has in place should give consumers confidence that their food, including dietary supplements, is safe. Most recently, FDA published a rule that prohibits the use in human food, including dietary supplements, of the cattle materials that have the highest risk of harboring BSE infectivity. Furthermore, most ingredients used to produce dietary supplements and most other food ingredients come from cattle that are slaughtered when they are less than 30-months of age and, because of their age, present little risk of being BSE-positive.
Even though BSE-positive cows have been identified in the U.S., one of which was imported, the risk to human health from dietary supplements and other foods containing cattle-derived ingredients is extremely low.
What steps is FDA currently taking to ensure the safety of dietary supplements that contain bovine ingredients?
Most recently, FDA published a rule that prohibits the use in human food, including dietary supplements, of the cattle materials that have the highest risk of harboring BSE infectivity. The rule applies to both domestic and imported dietary supplements and their ingredients. In addition, most ingredients used to produce dietary supplements and most other food ingredients come from cattle that are slaughtered when they are less than 30-months of age and, because of their age, present little risk of being BSE-positive. Further, the restrictions by USDA on the use of certain cattle and cattle tissues in human food also reduce the risks that potentially infective tissue would be used in dietary supplements. FDA also has proposed a requirement that manufacturers and processors that use cattle material in their products would be required to keep records demonstrating that these materials do not contain prohibited cattle material and that these records be made available to FDA for inspection.
Given the BSE case in Washington State and the case in Texas, should consumers be concerned about cosmetics made using tallow from the rendering process?
No. The World Health Organization considers tallow to be a low risk for transmission of BSE. Specifically, the rendering process separates fats from proteins. Because the disease is transmitted by prions, which are a type of protein, they would be separated by the rendering process from the tallow or fat, which is the portion that goes into cosmetics. Additionally, the tallow is processed with excessive heat and pressure which may further minimize any risk of infectivity prior to use in cosmetics.
What about the use of gelatin, another bovine-related material, in cosmetics and dietary supplements and other foods?
FDA's rule prohibiting the use of the cattle materials that have the highest risk of harboring BSE infectivity in human food applies to gelatin. Therefore, gelatin used in human food may not be made from these cattle materials.
When and how did BSE in cattle occur?
BSE in cattle was first reported in 1986 in the United Kingdom (UK). The exact origins of BSE remain uncertain, but it is thought that cattle initially may have become infected when fed feed contaminated with scrapie-infected sheep meat-and-bone meal (MBM). Scrapie is a prion disease in sheep similar to BSE in cattle. The scientific evidence suggests that the U.K. BSE outbreak in cattle then was expanded by feeding BSE-contaminated cattle protein (MBM) to calves. The definitive nature of the BSE agent is not completely known. The agent is thought to be a modified form of a protein, called a prion, which becomes infectious and accumulates in neural tissues causing a fatal, degenerative, neurological disease. These abnormal prions are resistant to common food disinfection treatments, such as heat, to reduce or eliminate their infectivity or presence. Research is ongoing to better understand TSE diseases and the nature of prion transmission.
Is BSE in cattle the same disease as CWD in deer and elk in the U.S.?
BSE is a Transmissible Spongiform Encephalopathy (TSE), a family of similar diseases that may infect certain species of animals and people such as scrapie in sheep and goats, BSE in cattle, chronic wasting disease (CWD) in deer and elk, and variant Creutzfeldt-Jakob disease (vCJD) in people.
To date, there is no scientific evidence that BSE in cattle is related to CWD in deer and elk. FDA is working closely with other government agencies and the public health community to address CWD in wild and domesticated deer and elk herds. Wildlife and public health officials advise people not to harvest, handle, or consume any wild deer or elk that appear to be sick, regardless of the cause, especially in those states where CWD has been detected.
What countries have reported cases of BSE or are considered to have a substantial risk associated with BSE?
These countries are: Albania, Austria, Belgium, Bosnia-Herzegovina, Bulgaria, Croatia, Czech Republic, Denmark, Federal Republic of Yugoslavia, Finland, France, Germany, Greece, Hungary, Ireland, Israel, Italy, Liechtenstein, Luxembourg, former Yugoslavia Republic of Macedonia, The Netherlands, Norway, Oman, Poland, Portugal, Romania, Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Japan, and United Kingdom (Great Britain including Northern Ireland and the Falkland Islands).
Source: U.S. Food and Drug Administration
sourceLast Editorial Review: 2/18/2008
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