Agriculture

Bovine Spongiform Encephalopathy

Updated February 12, 2004

On December 23, 2003, a Holstein cow in the state of Washington was identified with Bovine Spongiform Encephalopathy (BSE), or "mad-cow" disease. This became the first confirmed case of BSE in this country, leading policy makers to review state laws and policies that ensure the food supply is free of any BSE prions.

BSE is a fatal neurological disorder that affects cattle, causing them to lose coordination, reduce bulk and weight and changes their temperament. Because the disease can be transmitted to humans and can be devastating to the cattle industry, the government has taken aggressive measures to ensure that cattle in this country are free of any BSE.

This disease afflicts the brain and nervous system, causing "pockets" to form when prions (proteinaceous infectious agents) begin growing, resulting in a sponge-like brain. BSE is part of a family of transmittable spongiform encephalopathies (TSE), which have been known to afflict (in some form) sheep, goats, deer, elk, minks, large cats, cattle and humans. There is no known cure or treatment, and the result is ultimately fatal. Because they have no DNA or RNA, prions do not succumb to normal sterilization, continuing to thrive even after the animal dies. The only successful method of destruction is high temperature burning of the carcass.

The federal government, through the U.S. Department of Agriculture, the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC), has taken a dual approach to addressing this disease; first, by banning or restricting imports of cattle and cattle parts from countries identified with BSE, and second, by surveying cattle for the disease and humans from BSE-related illness.

This effort requires much cooperation with the states, mostly through the state departments of agriculture and state departments of health. USDA works mainly with the departments of agriculture, making certain that this country remains free of any BSE-infected cattle. CDC works with the departments of health, providing surveillance data of persons they may Creutzfeldt-Jakob Disease (CVD), which may result from BSE cattle. The FDA works with both agencies.

State legislatures can adopt laws more stringent than the federal requirements, but they cannot limit federal actions. Legislatures also have an important role regarding the funding and resources available to the departments of health and agriculture to identify and control the spread of this disease.

Impact on Humans

In terms of human exposure to "mad cow disease," the human counterpart is called Creutzfeldt-Jakob Disease (CVD), which like BSE slowly spreads through the brain and nervous system, causing dementia and loss of motor skills. Like BSE, medical science has no treatment for CVD and ultimately causes death in its victims.

A link between BSE in cattle CVD in humans has not been confirmed, but a new variant of CVD (nvCVD) discovered in 1996 in Britain has been positively linked to BSE. Since that time, 153 cases of nvCVD have been suspected or confirmed; 143 being in the UK, 6 in France, and one in Ireland, Italy, Canada and the US (the US case came from a person who was born and raised in the UK. No other cases of nvCJD have been diagnosed in the U.S.) But like BSE, the only certain method of confirming the disease is through an examination of the brain tissue after death.

The main effort in the U.S. to combat this disease is through surveillance programs. The CDC reviews death certificates to determine the number of CVD cases have occurred. States contribute to this system and have a passive surveillance system in place to review for cases of the disease. ("Passive" surveillance means that there is no active screening for cases or exposure to a disease, such as there is for HIV or blood screening of newborns for genetic disease).

TSE in other Animals

Though BSE has been found in only one animal in the US, TSEs have been found in deer and elk in Colorado, Kansas, Nebraska, Oklahoma, South Dakota, Wisconsin, and Wyoming, leading to four people being infected with and later dying from CVD. Better known as chronic wasting disease, it is a type of TSE and has lead to concerns that it may infect the cattle and human populations.

Federal Efforts to Limit Bovine Spongiform Encephalopathy

Cases of BSE first were identified in the United Kingdom in 1986, and due to cattle feeding practices in that country quickly spread. The height of the epidemic came in January 1993, when 1000 cases a week were being reported. Before the government could control the outbreak, 180,000 cases of infected cattle were discovered, all of which were destroyed. The disease spread outside of the UK, with about 1800 other cases being found in Ireland, France, Germany, Spain, Denmark, Italy, and most recently, Canada.

Only in the past few months did a case appear in Alberta, Canada, and USDA has confirmed that the Holstein affected in Washington came from Canada.

Restrictions on Imports

BSE can enter the U.S. through several methods, including the importation of live cattle, animal tissues, and animal byproducts or ruminant (cattle, sheep, goats, etc.) feed imports from BSE-affected countries. Therefore, the federal government imposed a ban on any cattle coming from countries listed as affected by BSE or at risk for BSE, followed by restrictions on the importation of live ruminants and ruminant meat products from BSE listed countries. Dietary supplements and certain cosmetic ingredients derived from cattle also have been prohibited in the US if they come from these countries. (Milk and milk products are not banned because milk from BSE-affected cattle have not shown to cause infection). These restrictions apply to the European Union, Japan, Israel and Canada, among other countries.

Meat and bone meal and animal feeds also provide a pathway for BSE, and the US has restricted or banned such products from BSE-listed countries

Domestic Efforts

To ensure the domestic food industry complies with regulations, the FDA, along with state feed control officials, inspect feed mills, ruminant feeders, diaries, and a number of other industries involved with feeding operations. A recent survey of rendering plants, which process most domestic meat and bone meal, found 93 percent in compliance with state and federal requirements.

USDA's Food Safety and Inspection Service (FSIS) inspects cattle before they go to slaughter to determine if they have BSE or other central nervous system impairments. If any animals are showing signs of BSE, the animal is condemned and its brain submitted to USDA National Veterinary Services Laboratories for examination. With over 17,000 cattle brains being examined from almost every state and Puerto Rico, no evidence of BSE or any other TSE has been discovered by FSIS.

Also, both USDA and FDA have undertaken major education efforts for state veterinarians and feed control officials in every state to ensure they know the signs of BSE in cattle and the importance of regulatory prevention efforts.

Regulations to Prevent BSE and nvCVD

USDA, FDA and CDC continue to offer regulatory and policy initiatives to prevent the spread of BSE and nvCVD. A major initiative involves surveillance of both cattle and humans, to determine the extent, if any, of mad cow or nvCVD in this country. A second initiative will address regulatory restrictions, such as prohibiting the brain and spinal cord from cattle in human food, the nervous system in boneless beef product, or the banning the use of vertebral column from cattle.

USDA promulgated rules recently regarding methods of disposal for downer animals (animals that die before reaching the slaughterhouse), due to fears of spreading BSE.

The following regulations were published in the Federal Register, and went into effect, on January 12, 2004:

Docket No. 03-048N, Bovine Spongiform Encephalopathy Surveillance Program.

Docket 03-025IF, Prohibition of the Use of Specified Risk Materials for Human Food and Requirements for the Disposition of Non-Ambulatory Disabled Cattle.

Docket No. 03-038IF, Meat Produced by Advanced Meat/Bone Separation Machinery and Meat Recovery (AMR) Systems.

Docket No. 01-033IF, Prohibition of the Use of Certain Stunning Devices Used to Immobilize Cattle During Slaughter.

The four articles below from the CDC webpage give a tremendous amount of information about human exposure to BSE and CJD.

Questions and answers about BSE and CJD
http://www.cdc.gov/ncidod/diseases/cjd/bse_cjd_qa.htm

CJD Fact Sheet
http://www.cdc.gov/ncidod/diseases/cjd/cjd_fact_sheet.htm

CJD Infection Control Practices
http://www.cdc.gov/ncidod/diseases/cjd/cjd_inf_ctrl_qa.htm

Update 2002: Bovine Spongiform Encephalopathy and Variant Creutzfeldt-Jakob Disease
http://www.cdc.gov/ncidod/diseases/cjd/bse_cjd.htm

NCSL Disclaimer

The above abstracts policies governing bovine spongiform encephalopathy. This report is the property of The National Conference of State Legislatures (NCSL) and is intended as a reference for state legislators and their states. NCSL makes no warranty, expressed or implied, or assumes any legal liability or responsibility for third partys' use of this information, or represents that its use by such third party would not infringe on privately owned rights.

Doug Farquhar, J.D.
303/364-7700

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