Bovine spongiform encephalopathy (BSE) or "mad cow disease"
| Key Information about BSE | |
| United States Department of Agriculture | |
| BSE Test Results | |
| BSE enhanced surveillance | |
| BSE enhanced surveillance toll-free number | |
| USDA BSE resources | |
| USDA/Animal and Plant Health Inspection Service BSE fact sheet | |
| USDA BSE Response Plan Summary (pdf) | |
| USDA/Animal and Plant Health Inspection Service BSE info | |
| USDA Food Safety Inspection Service BSE information | |
| USDA Economic Research Service beef stats | |
| U.S. Food and Drug Administration | |
| FDA BSE Information | |
| Centers for Disease Control | |
| BSE and CJD Information and Resources | |
| OIE (World Organization for Animal Health) | |
| BSE Information | |
| Canadian Food Inspection Agency | |
| Bovine Spongiform Encephalopathy (BSE) in North America | |
| United Kingdom Department for Environment, Food and Rural Affairs | |
| BSE Home page | |
| Industry Links | |
| National Cattlemen's Beef Association BSE page | |
The USDA announced on December 23, 2003 the first diagnosis of bovine spongiform encephalopathy (BSE or mad cow disease) in the United States.
BSE is not contagious. It is unlikely that an outbreak of BSE will occur in North American cattle because the United States and Canada had already taken action in 1997 to prevent transmission via contaminated feed. The risk to human health from BSE is miniscule. However the diagnosis may seriously affect beef exports from the US.
What is BSE?
Bovine spongiform encephalopathy is a disease of adult cattle affecting the central nervous system. It also is sometimes referred to as mad cow disease. Affected cattle develop progressive behavior changes, abnormal posture, incoordination, reduced milk production and weight loss. The disease typically occurs in cattle 5 years of age or older. It is rare for cattle younger than 3 years old to be affected.
The disease was first diagnosed in Great Britain in 1986. It soon became apparent that an outbreak was occurring in British cattle. The epidemic peaked in 1993 at 1,000 cases per week and has since waned. Currently about 25 cases per week are identified in Great Britain. BSE has been diagnosed in native cattle in several other European nations, Japan, Israel, and Canada. The cow diagnosed with BSE in the United States was imported from Canada as an adult.
What causes BSE?
BSE is one of a family of similar diseases known as transmissible spongiform encephalopathies (TSE). Different TSE diseases are known to occur in several species such as sheep, cattle, deer and elk, mink, squirrels and man. The cause of TSE diseases is not known for sure, but a leading theory is that the disease is transmitted by ingestion of an infectious prion protein.
It is not known how BSE originated. However, it is clear that the outbreak of BSE in Great Britain and Europe was caused because in the early 1980s cattle were exposed to a common source of feed contaminated with the infectious prion protein. Ingestion of contaminated feed products remains the primary risk factor for transmission of the disease to cattle. Transmission from animal to animal is unlikely to occur.
Why has BSE in Europe caused such concern?
In 1996 a possible link was proposed between BSE and a disease of humans recently observed in Britain. The disease in humans was a variant form of CJD (Creutzfeldt-Jakob Disease), a fatal TSE of man. The link between BSE and new variant CJD (vCJD) is likely. To date there have been 143 definite or probable cases of vCJD diagnosed in people from the United Kingdom. The link between vCJD and consumption of BSE-contaminated beef was devastating to the European beef industry although consumer confidence in beef is returning.
