On December 23, 2003, the U.S. Department of Agriculture (USDA) announced a presumptive diagnosis of bovine spongiform encephalopathy (BSE, or "mad cow" disease) in an adult 4- to 41/2-year-old Holstein cow from Washington State. Samples were taken from the cow on December 9 as part of USDA's BSE surveillance program. The BSE diagnosis was made on December 22 and 23 by histopathology and immunohistochemical testing at the National Veterinary Services Laboratory, Ames, Iowa. Final confirmatory testing is pending at an international reference laboratory in England.

USDA and the Food and Drug Administration (FDA) share primary federal responsibility for the investigation. Other Department of Health and Human Services’ (DHHS) agencies providing support include the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH). Under DHHS's BSE Action Plan, surveillance for human disease is primarily the responsibility of CDC; protection is primarily the responsibility of FDA; and research is primarily the responsibility of NIH.

USDA has launched an epidemiologic investigation to determine the source of the disease. Preliminary investigations indicate that beef from the slaughtered cow had been prepared for human consumption after the animal received a pre- and post-slaughter inspection by a USDA, Food Safety and Inspection Service (FSIS) veterinarian. On December 23, 2003, FSIS announced the recall of all beef derived from cattle slaughter on December 9 at the involved slaughter plant (http://www.fsis.usda.gov/OA/recalls/prelease/pr067-2003.htm). Efforts to recall beef products from establishments that may have received these products are in progress. FSIS' designation of this recall as Class II (i.e., remote probability of adverse health consequences) is due to the very low likelihood that the beef being recalled contains the infectious agent that causes BSE. The beef products were cuts that would not be expected to be infected or have an adverse public health impact.

Strong evidence indicates that BSE has een transmitted to humans primarily in the United Kingdom, causing a variant form of Creutzfeldt-Jakob disease (vCJD). In the United Kingdom, where over 1 million cattle may have been infected with BSE, a substantial species barrier appears to protect humans from widespread illness. As of December 1, 2003, a total of 153 vCJD cases had been reported worldwide; of these, 143 cases had occurred in the United Kingdom. The BSE risk to human health from consuming beef in the United States is extremely low.

The Centers for Disease Control and Prevention (CDC) monitors the trends and current incidence of CJD in the United States by analyzing death certificate information from U.S. multiple cause-of-death data compiled by the National Center for Health Statistics. With the support of the Council of State and Territorial Epidemiologists, CDC conducts follow-up review of clinical and neuropathology records of CJD decedents younger than 55 years of age who are identified through the national mortality data analysis.

In addition, CDC has since 1996 provided support for the National Prion Disease Pathology Surveillance Center at Case Western Reserve University in Cleveland, Ohio. This pathology center provides free, state-of-the-art diagnostic services to U.S. physicians. It also helps to monitor the possible occurrence of emerging forms of prion diseases, such as vCJD, in the United States. For more information about the center visit its website at: http://www.cjdsurveillance.com

For more information, see the following websites:
- USDA http://www.aphis.usda.gov/lpa/issues/bse/bse.html
- FDA http://www.fda.gov/bbs/topics/NEWS/2003/NEW00999.html
- CDC http://www.cdc.gov/ncidod/diseases/cjd/cjd.htm
- NIH http://www.nlm.nih.gov/medlineplus/creutzfeldtjakobdisease.html.

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