What Is Mad Cow Disease?

By The Associated Press

Japan has halted imports of American beef because it discovered a shipment containing bone that Asian countries consider at risk for mad cow disease.

What is mad cow disease, and why is it a concern?

-Mad cow disease is the common term for bovine spongiform encephalopathy, or BSE. It’s a degenerative nerve disease in cattle. It’s been found in more than two dozen countries, including the United States and Japan.

-BSE is linked to a rare but fatal human disease, variant Creutzfeldt-Jakob Disease. People get it by eating meat or cattle products contaminated with mad cow disease.

-No one is known to have contracted the vCJD in the United States. It’s turned up in two people who lived in the U.S., but they are believed to have been infected in the United Kingdom during an outbreak in the 1980s and 1990s.

-To protect the human food supply, the government requires that brains, spinal cords, vertebral columns and other tissues that can carry mad cow disease be removed when older cows are slaughtered. At-risk tissues are removed from slaughtered cows older than 30 months because infection levels are believed to rise with age.