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Fact Sheet
DRUG SAFETY IS A FOREMOST PRIORITY OF THE FOOD AND DRUG ADMINISTRATIONOverview: Department of Health and Human Services (DHHS) and its agencies, including the Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and the National Institutes of Health (NIH) are working with the U.S. Department of Agriculture (USDA) and other partners to prevent BSE, commonly known as “mad cow disease,” from posing a public health threat in the United States. BSE (bovine spongiform encephalopathy) is a fatal disease that causes progressive neurological degeneration in cattle. Similar to BSE, classical Creutzfeldt-Jakob disease (CJD) is a rare disease that occurs in humans and was identified long before BSE in cattle. In 1996, following outbreaks of BSE among British cattle, scientists found a possible link between BSE and a new variant of CJD (vCJD). While it is not certain how BSE may be spread to humans, evidence indicates that humans may acquire vCJD after consuming BSE-contaminated cattle products. BSE was first reported among cattle in the United Kingdom (UK) in November 1986. The source of the BSE outbreak is uncertain, but it is thought to have been amplified by feeding cattle with meat-and-bone meal from BSE-infected cattle. To contain the disease, the British government took numerous measures, including a ban on the use of meat-and-bone meal in cattle feed, and slaughter of all cattle believed to be infected. These steps reduced the number of confirmed BSE cases in the UK from 36,680 in 1992 to approximately 30 in 2005. Cases of BSE have been identified also among cattle in other countries, mostly in Europe. Two BSE infected cows have been found in the U.S., one of which was imported from Canada. Following the outbreak in Europe, U.S. agencies acted quickly to prevent BSE or vCJD from becoming a significant public health threat in this country. The main steps they took include:
BACKGROUND ON BSE AND vCJD BSE (sometimes referred to as “mad cow disease”) and variant and classic CJD belong to the unusual group of progressive, degenerative neurological diseases known as transmissible spongiform encephalopathies (TSEs). These diseases are characterized by a long incubation period of up to several years, during which there is no visible indication of the disease. The incubation period for BSE among cattle ranges from three to eight years; for vCJD among humans, the incubation period is unknown, but is at least five years and could extend up to 20 years or longer. The diseases are invariably fatal; there is no known effective treatment or cure. It is believed that vCJD may be acquired from eating food products containing the BSE agent, and there is strong epidemiologic and laboratory evidence for a causal association between vCJD and BSE. The absence of confirmed cases of vCJD in geographic areas free of BSE supports a causal association. BSE among cattle was first described in the UK in November 1986. Epidemiological evidence established that the outbreak of BSE was related to the production and use over many years of BSE-contaminated meat-and-bone meal in cattle feed. The source of the BSE outbreak is uncertain. There is strong evidence and general agreement that the outbreak was amplified by feeding BSE-contaminated bovine meat-and-bone meal to young calves. The vast majority of BSE cases have been reported in the UK. Through July 2005, about 185,000 cases of BSE have been confirmed there in more than 35,000 herds of cattle. The UK epidemic peaked in January 1993 at nearly 1,000 new cases per week. In addition, between 1989 and 2005, at least 5,200 cases of BSE were reported in other countries, mostly in continental Europe. Among humans, the total worldwide number of known vCJD cases is approximately 170, including 158 in the UK, eight in France, one in Italy, one in Canada, one in Japan, one in Ireland, and two in the United States. Both U.S. victims had been raised in the UK during its BSE epidemic, and most likely were infected before they left the country. European countries have instituted a variety of public health control measures, such as BSE surveillance, the culling of sick animals, the banning of specified risk materials (SRMs), or a combination of these, to prevent potentially BSE-infected tissues from entering the human food chain. Due to its early outbreak and the extent of the epidemic, the most stringent of these measures have been applied in the UK. In June 2000, the European Union Commission on Food Safety and Animal Welfare adopted a decision requiring all member states to remove SRMs from the animal feed and human food chains as of October 1, 2000; such bans had already been instituted in most member states. U.S. ACTIONS: STEPS TO MINIMIZE ANY POSSIBLE RISK Only two BSE-infected cows have been found in the U.S., one of which had been imported from Canada. The other, identified in Texas in June 2005, was born in the U.S. When diagnosed, the cow was 12 years old, and it had in all likelihood consumed BSE infectious material before 1997, when the Food and Drug Administration (FDA) banned the use of feeds likely to carry the infectious agent. By November, 2005, only two persons who have been diagnosed with vCJD in the U.S. Both had almost certainly become infected while living in UK. BSE- and vCJD-prevention has been a major goal of all involved U.S. government and state agencies. Here are the key programs: DHHS Action Plan
In August 2001 the DHHS unveiled a department-wide action plan outlining new steps to improve scientific understanding of BSE and related diseases known as TSEs. The plan incorporates a comprehensive approach to further strengthen surveillance, increase research resources, and expand existing inspection efforts to prevent BSE from entering or taking hold in the U.S. The Secreatary’s action plan outlines four areas of responsibility within the Department: surveillance, protection, research and oversight. This effort is coordinated with other government agencies, the private sector, and the international community. The action plan is on the Web at: frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=2001_register&docid=01-21145-filed . USDA’s Import/Inspection Protections USDA’s responsibilities include protecting both human and animal health. USDA’s Food Safety and Inspection Service (FSIS) operates a substantial program for inspecting animals intended for human consumption. USDA examines all cattle before they can be approved for use as human food; use of cattle with unidentified neurological diseases is prohibited. USDA examines more than 33 million cattle each year. The USDA’s Animal and Plant Health Inspection Service (APHIS) enforces import regulations covering animals and animal products offered for import into the United States to prevent the importation of diseases such as BSE, foot-and-mouth disease, rinderpest and African swine fever. In 1989, USDA issued restrictions prohibiting the importation of live ruminants from countries where BSE is known to exist in native cattle. On December 12, 1997, APHIS took further steps to stop the importation of live ruminants and most ruminant products from all of Europe. In June 2004 following the discovery of the first case of BSE in the U.S. (in a cow imported from Canada), USDA expanded its BSE surveillance program with the goal of testing approximately 300,000 U.S. cattle in one year. USDA has recently announced that the increased level of surveillance for BSE in U.S. cattle will be continued indefinitely. DHHS Protections Agencies within DHHS have a long-standing commitment to research, epidemiological studies and consumer protection involving BSE and variant and classic CJD. Cattle and other Ruminant Feed Restrictions: In 1997, FDA published a final regulation designed to prevent the spread of BSE through animal feed. The 1997 rule prohibits the use of most mammalian protein in feeds for ruminant animals, such as cows, sheep, and goats. In October 2005, FDA proposed an additional rule to ban certain high-risk materials in all animal feeds, including pet foods. The proposed rule includes a prohibition of the use of brains and spinal cords from cattle 30 months of age or older, and from cattle of any age not inspected and passed for human consumption. Protecting FDA-Regulated Food and Cosmetics: In July 2004, FDA issued a rule, effective immediately, which prohibited the use in human foods (including certain meat-based products and dietary supplements) and cosmetics of certain high-risk cattle materials that can potentially carry the BSE-infectious agent. This ban includes “specified risk materials” (SRMs) such as the brain, skull, eyes, and spinal cord of cattle age 30 months or older; material from non-ambulatory disabled cattle; and material from cattle not inspected and passed for human consumption. While maintaining the highest safety standards, some of the 2004 requirements were amended in September 2005 on the basis of new scientific information. In addition, the FDA has proposed to require that manufacturers and processors of FDA-regulated human food and cosmetics containing cattle-derived material maintain records showing that prohibited materials are not used in their products. Protecting the Blood Supply: In August 1999, FDA issued guidelines to blood centers on how to reduce the risk of transmission of vCJD to recipients of blood products. This prudent measure recommended procedures for deferring potential donors who may have been significantly exposed to food and other cattle-derived products in BSE-endemic countries. FDA’s present guidelines ask blood centers to permanently defer the following blood donors:
Protecting FDA-Regulated Products (including vaccines): Since 1992, FDA has sent letters to manufacturers of FDA-regulated products providing guidance on the use of bovine materials from countries affected by BSE. In December 1993, May 1996, and April 2000 the FDA requested that manufacturers of FDA-regulated products intended for humans do not use bovine-derived materials from BSE countries. FDA also asked vaccine manufacturers to evaluate all bovine-sourced material used in vaccines, and to use such material only from BSE-free countries. FDA routinely inspects all manufacturers of FDA-regulated products for compliance with the terms of their approved applications and other requirements. Protecting FDA-Regulated Tissue Products: FDA’s current draft guidance recommends that the tissue establishments determine ineligible the same donors who would not qualify as blood donors (see above). In addition, the agency recommends ineligibility status for donors of tissues who have been diagnosed with dementia or any degenerative or demyelinating disease of the central nervous system (CNS) or other neurological disease of unknown etiology. Research: The National Institutes of Health (NIH) has long been actively researching CJD and kuru, a related TSE disease in humans, as well as BSE in animals. In the 1960s and 1970s, the Nobel Prize-winning team at the NIH Laboratory of Central Nervous System Studies conducted experiments on the oral transmission of CJD, kuru, and scrapie, a similar disease that affects sheep and goats. In the 1980s, scientists at the University of California in San Francisco used extracts of scrapie-infected brains to postulate that the infectious agent was a single protein, PrP. Naming this class of infectious proteins as “prions,” scientists showed that prions were a variant of normal proteins. Further research at NIH in the 1990s linked two outbreaks of CJD in Europe and Israel to a genetic mutation in the victims. It is now known that about 10 percent of CJD can be inherited, although it is not known if the genetic defect causes the disease or if another agent, such as a prion, is required. Today, researchers in the U.S. and around the world are collaborating in the search for methods to detect, prevent and treat prion-linked diseases. NIH scientists are providing input to the investigation of vCJD cases in Europe and have developed a diagnostic test for the disease that can be performed before death. Disease Surveillance: The Centers for Disease Control and Prevention (CDC) in Atlanta conducts surveillance for CJD through examination of death certificate data for U.S. residents. Based on this surveillance, during the period 1979 to 1998, the annual incidence of classic CJD (not the new variant CJD related to BSE) remained stable at approximately one case per million persons. In addition to the ongoing review of national CJD mortality data, CDC conducted active CJD surveillance in its four established Emerging Infectious Program areas (in Minnesota, Oregon, Connecticut and the San Francisco Bay area) and in a metropolitan Atlanta site during April and May 1996. In 1996, CDC worked with the Council of State and Territorial Epidemiologists to initiate an ongoing follow-up review of clinical and neuropathology records of CJD decedents aged younger than 55 years who are identified through the national mortality data analysis. This age group is targeted for surveillance because, while classic CJD is normally found in people aged 60 and older, vCJD is generally found in younger individuals. Also in 1996, the American Association of Neuropathologists, in collaboration with CDC, alerted its members about the new vCJD and requested reports of any possible cases. These continuing surveillance efforts have not detected evidence of endemic vCJD in the United States. ### Note: All HHS press releases, fact sheets and other press materials are available at http://www.hhs.gov/news. Last Revised: August 16, 2006 |
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