Bovine Spongiform Encephalopathy (BSE)
BSE, widely known as "Mad Cow Disease," is a fatal disease of cattle first recognized in the United Kingdom in 1986. Most research suggests an abnormal protein, known as a prion, causes BSE. Scientific evidence shows the same disease agent that causes BSE in cattle also causes the new human disease, variant Creutzfeldt–Jakob disease. BSE spreads in cattle primarily through animal feed containing processed ruminant products. Cattle infected with BSE take 2 to 8 years before showing signs of disease, which include changes in temperament such as nervousness or aggressiveness, and progressive incoordination.
April 24, 2012
The National Veterinary Services Laboratory in Ames, Iowa confirmed that a routine surveillance sample obtained from a Holstein cow carcass at a rendering plant in the Central Valley of California was positive for the atypical strain of Bovine Spongiform Encephalopathy (BSE). No part of this carcass entered the human or animal food chain.
BSE is a Foreign Animal Disease to the United States caused by an infectious protein particle called a prion. There are two strains of BSE. The typical strain, which was linked to outbreaks in the United Kingdom and Canada, is known to be preventable through the elimination of BSE-contaminated feed. Food and Drug Administration regulations have prohibited the inclusion of mammalian protein in feed for cattle and other ruminants since 1997 and have also prohibited high risk tissue materials in all animal feed since 2009. The typical strain of BSE has never been identified in U.S. born cattle. The atypical strain of BSE appears to represent a sporadic disease that is different from what is usually seen.
A Joint USDA/CDFA Incident Command is being established to manage the trace back investigation of this case for identification and removal of other at-risk cattle.
BSE in North America
To date, there have been twenty-two Bovine Spongiform Encephalopathy (BSE) cases diagnosed in North America. See CDFA North America Summary, April 2012 (PDF).
The current hypothesis is that BSE entered North America through cattle imported from the UK during the 1980’s. There were 182 UK cattle imported directly into Canada and 300 imported in the US from 1982 to 1990. Following their arrival into North America, the UK imports became members of Canada or US national cattle herds.
Since the 1980’s, both the US and Canada have implemented preventative measures to ensure cattle and human health.
BSE in the United Kingdom
BSE was first diagnosed in the U.K. in November 1986 at the Central Veterinary Laboratory, Weybridge. The initial two BSE positive cows originated from two herds in different parts of England, but showed the same abnormal neurological symptoms.
In response to the emergence of BSE, epidemiological studies were started in April 1987. Epidemiogical analysis showed the disease was spread by contaminated feed.
The epidemic reached its peak early in 1993. Since then the number of cases has decreased. In 2003, there had been around 25 new BSE suspect cases per week; at the peak of the epidemic in 1992–93 there were over 1000 suspected cases per week.
BSE in the United States
On March 13, 2006, BSE was confirmed in a non–ambulatory, approximately 10–year old crossbred beef cow sampled on a farm in Alabama by a private veterinarian. No part of the animal entered the human or animal food chain. The cow had resided on the farm for less than a year. The investigation has been completed.
On June 24, 2005, BSE was confirmed in a cow slaughtered in November 2004. The cow was sampled for BSE at a pet food facility in Texas. DNA tests confirmed that the approximately 12–year old Brahma–cross cow was born and raised in Texas. The herd was quarantined and cattle that were in a similar birth group and/or ate the same feed as the infected cow were traced and removed.
The first case detected in the U.S. was confirmed on December 25, 2003, by The Veterinary Laboratories Agency in Weybridge, England. This case was in an adult Holstein cow slaughtered in the State of Washington. The epidemiological investigation and DNA test results confirmed the infected cow was not indigenous to the U.S., but was born and became infected in Alberta, Canada. Animals with known or potential risk for having been infected with the BSE agent and all progeny from the index cow in the U.S. were depopulated. All carcasses were properly disposed of in accordance with Federal, State, and local regulations.
SURVEILLANCE IN THE UNITED STATES
BSE surveillance began in 1990. USDA has an ongoing, comprehensive, interagency surveillance program to detect signs of BSE in the United States. USDA's BSE surveillance program samples approximately 40,000 animals each year and targets cattle populations where the disease is most likely to be found.
The targeted population for ongoing surveillance focuses on cattle exhibiting signs of central nervous disorders or any other signs that may be associated with BSE, including emaciation or injury, and dead cattle, as well as non-ambulatory animals. Samples from the targeted population are taken at farms, veterinary diagnostic laboratories, public health laboratories, slaughter facilities, veterinary clinics, and livestock markets. In addition, approximately 5,000 samples each year are collected from renderers and similar salvage facilities.
USDA will help defray costs incurred for transportation, disposal, storage and testing.
- Ensuring all cattle, including dead animals, are identified before leaving the premises
- Keeping accurate animal identification and movement records
- Keeping accurate feed records
- Reporting cattle with neurological signs to your veterinarian
- Disposing of carcasses appropriately, such as with a licensed renderer.
PRODUCERS CAN ASSIST IN THE SURVEILLANCE EFFORT BY:
To report high–risk cattle call this toll–free number: 1–866–536–7593
BSE AND HUMAN HEALTH
Scientific evidence shows the same disease agent that causes BSE in cattle also causes the new human disease, variant Creutzfeldt–Jakob disease (CJD). Variant CJD (vCJD) is a rare, degenerative, fatal brain disorder in humans. The probable transmission of vCJD is consumption of the BSE agent.
The vCJD can be confirmed only through examination of brain tissue obtained by biopsy or at autopsy.
- Predominantly affects younger people
- Prominent psychiatric or sensory symptoms at the time of clinical presentation
- Delayed onset of neurologic abnormalities, including ataxia within weeks or months, dementia and myoclonus late in the illness, a duration of illness of at least 6 months
- Diffusely abnormal non-diagnostic electroencephalogram.
CHARACTERISTICS OF vCJD:
California Creutzfeldt–Jakob Disease (CJD) Surveillance Project
The California Creutzfeldt–Jakob Disease Surveillance Project is funded by the federal Centers for Disease Control and Prevention (CDC) through the California Emerging Infections Program (EIP) to improve the public health capacity to detect cases of CJD.
Centers for Disease Control: BSE Information Site
World Health Organization BSE Infromation (PDF)
U.S. Preventing the Introduction & Spread of BSE
Since 1989, the U.S. Government has taken a series of preventive actions to protect against this animal disease. This includes USDA prohibitions on the importation of live ruminants, such as cattle, sheep, goats and most ruminant products from countries that have been or are considered to be at risk for having BSE.
In August 1997, the Food and Drug Administration promulgated regulations to prohibit the recycling of the high risk material in animal feed. The rule prohibits feeding most material from mammals to cattle or other ruminant animals. In 2009, the feed controls were enhanced to prohibit most proteins, including potentially BSE infectious tissues known as "specified risk materials" (SRM), from all animal feeds, pet foods and fertilizers.
In addition, the FDA and the state regulatory agencies have increased the number of inspections of renderers, animal feed manufacturers, feed mills, and other firms responsible for keeping prohibited mammalian protein out of cattle and other ruminant feed. FDA has dedicated more resources to these animal feed inspections and has upgraded its tracking system and database to ensure effective and timely follow–up.
Since the animal feed rule became effective in August 1997, FDA continues to annually inspect the firms that actually handle prohibited material.
- Ban non–ambulatory cattle from the human food chain
- Ban specified risk materials (skull, brain, trigeminal ganglia, eyes, vertebral column, spinal cord and dorsal root ganglia) of cattle over 30 months of age and a portion of the small intestine of cattle of all ages from human food
- Hold cattle tested for BSE at slaughter until confirmed negative for BSE
- Ban neural tissue in "advanced meat recovery" products labeled "meat"
- Ban air–injection stunning
- Ban mechanically separated meat in human food
- Implement a national animal identification system.
On December 30, 2003 the USDA announced additional safeguards against BSE:
In 2005, a risk assessment done by Harvard University showed the risk of BSE occurring in the United States as extremely low. The report also determined that early protection systems put into place by the USDA and Department of Health and Human Services have been largely responsible for keeping BSE out of the United States and in preventing it from spreading.
FDA Feed Control Information
Harvard Risk Assessment
COMPLIANCE WITH THE RUMINANT FEED BAN IN CALIFORNIA
California's rendering industry processes over one million tons of waste material to produce about 275,000 tons of animal product yearly. Approximately 50% of the rendered product made in California is exported. The remainder is used in California in feed for swine, poultry and aquaculture, and as fertilizer. Through a partnership agreement with the FDA, personnel with the Feed, Fertilizer, and Livestock Drugs Regulatory Services (FFLDRS) Branch of CDFA are commissioned and credentialed to inspect and complete an official Food and Drug Administration inspection report for feed-manufacturing facilities in California.
In cooperation with the FDA, all facilities that manufacture formula feeds in California have been inspected for compliance with the ruminant feed ban, in addition to all rendering/protein blending firms. Inspections conducted at feed manufacturing facilities and ruminant feeding operations during the past 12 months have found no significant deviations from the FDA Rule on prohibited animal proteins.
Regulatory personnel regularly visit manufacturing facilities that use prohibited materials. Inspections and sampling of ingredients and finished feeds are conducted to ensure ongoing compliance with the ruminant feed ban. Additionally, dairy-producer facilities are inspected for compliance with the feed ban.
All feeds containing animal protein prohibited from ruminant feed are required by federal and state law to display on the label the cautionary statement, "Do Not Feed to Cattle or Other Ruminants". Compliance with the ruminant feed ban is also included as part of a comprehensive voluntary feed quality assurance inspection program for feed-manufacturing facilities conducted under the auspices of the Safe Animal Feed and Education Program of CDFA. Training seminars for the livestock feeding industry and commercial feed manufacturers have been given in cooperation with the FDA. Information on BSE prevention has also been provided to each dairy producer in CDFA newsletters.
CDFA Safe Animal Feed & Education Program (SAFE)