Whatever Happened to Mad Cow Disease?

March 7 -- In the end they found only one sick cow — only one out of 36 million slaughtered last year.

But to many people, even that single case was scary news. It dominated the headlines when the Department of Agriculture announced the case in Washington State on Dec. 23.

It could have been a major crisis for the nation's food system, but the government stepped in, quickly, with a carefully-prepared message: It's … just … one … animal.

"Despite this finding, we remain confident in the safety of our food supply," said Secretary of Agriculture Ann Veneman at her first news conference.

Mad cow disease affects the brain and spine of an animal. The government said it had already moved, years ago, to keep those parts from grocery stores and restaurants. They said even if one sick cow slipped through, meat that did not come in contact with brain tissue was safe. The department added that 38,000 pounds of beef from the infected animal's herd were recalled, even though there were no signs that other cows were diseased.

The campaign to calm the public clearly worked. Industry associations say that after some initial hesitation, Americans have gone on buying beef. On Wall Street, the stock prices of major beef producers and buyers, such as McDonald's and ConAgra, are near 52-week highs.

Are You Safe?

Most public-health experts contacted by ABCNEWS say they believe the American public is generally safe from mad cow. They say the United States is very unlikely to suffer a repeat of the crisis that befell Britain in the 1990s, when the disease was not yet understood and 140 people died.

There is no evidence that any Americans have been infected, though the disease is slow to progress.