The United States reported its first case of mad cow disease yesterday.
The disease — officially known as bovine spongiform encephalopathy, or BSE — is a chronic, degenerative disorder that attacks the central nervous system of cattle. It has been linked to a fatal brain-wasting disease in humans and has devastated international cattle trade from affected nations.
Agriculture Secretary Ann M. Veneman said the case poses minimal risk to human health. Underscoring concerns about safety and security, she emphasized that the case is not related to terrorism.
People do not need to alter their eating habits, she said.
“I plan to serve beef for my Christmas dinner, and we remain confident in the safety of our food supply,” she said.
Meanwhile, Japan and South Korea announced that they have temporarily banned the import of U.S. beef, an official said last night.
“We are now withholding the issuance of import permits” on U.S. beef, said Japanese Agriculture Ministry spokesman Hiroaki Ogura. “That means for now, [beef] imports have been banned.”
Japan is the leading export market for U.S. beef, accounting for 32 percent of U.S. exports last year, according to the U.S. Meat Export Federation. Mexico, Canada, South Korea and Hong Kong are the next-biggest markets.
Today, Taiwan and Singapore also announced a suspension of imports.
The Agriculture Department is still awaiting confirmation of its preliminary finding. A sample of the animal, a dairy cow from a farm in Washington state, was being flown to a lab in Britain. Results will not be available for three to five days.
The farm is in Mabton, about 150 miles southeast of Seattle. The department is tracing the animal, slaughtered at a nearby meatpacker, backward and forward through the food chain, Mrs. Veneman said.
“We’re in the very early stages of the investigation,” she said.
Washington state officials have quarantined the farm until the results return and the investigation is completed.
Until yesterday, no cases of mad cow disease had been cited in the United States, and only two cases of the disease have been reported in North America, in May and in 1993 in Canada.
The U.S. and Canadian cases are unlikely to be related, Mrs. Veneman said.
Reuters reported that Nevada would stop Washington dairy cattle at its border, and New Mexico has an emergency-response team on alert.
While 60 percent of Canadian beef is exported, only about 10 percent of U.S. beef is exported, said the National Cattlemen’s Beef Association.
The Canadian cases sent the price of related stocks, like hamburger giant McDonald’s, down and prompted the United States and other countries to immediately block live and processed cattle, sheep and goats from north of the border.
Yesterday’s announcement came after the markets closed. But in after-hours trading, shares of McDonald’s and Wendy’s dropped.
McDonald’s, the nation’s largest burger chain, dropped 84 cents a share, or 3.3 percent, to $24.44 by 6 p.m. in extended trading. Wendy’s, the third-largest chain, fell 90 cents, or 2.7 percent, to $38.76.
McDonald’s said the meatpacker in question has no connection to the company’s supply chain.
“We are confident … the Department of Agriculture are investigating this situation very seriously and are taking all the appropriate steps necessary to safeguard the beef supply,” Lisa Howard, McDonald’s spokeswoman, said in a statement.
Beef futures on the Chicago Board of Trade, trading at historical highs, closed up yesterday, but markets had not had time to react to the news.
The National Cattlemen’s Beef Association yesterday scrambled to assure consumers that American beef remains safe.
“Systems have been built over the last 15 years to prevent this disease from spreading and affecting human health or the food supply,” said Terry Stokes, the group’s chairman.
Mr. Stokes would not speculate on the economic effect of the case. While demand for red meat did not fall dramatically after the Canadian cases, that country’s industry was devastated because its largest market was closed off.
The cattle industry is the largest component of U.S. agriculture production, and is made up of more than 1 million small businesses — farms and ranches — operating in all 50 states, the association said.
The disease was first identified in Britain and peaked there in 1993. It later spread through Europe, with reported cases across the continent, including France, Spain, Germany and Italy. The cases prompted massive destruction of herds and devastated the European beef industry in 2000 and 2001.
The disease also prompted a consumer backlash against red meat in Europe, and the United States and other nations banned European beef. Mrs. Veneman said yesterday that the government was notifying trade partners of the U.S. case, but would not speculate on their responses.
Mad cow disease, which is believed to affect central-nervous tissue and not muscle tissue, was first diagnosed in Britain in 1986. About 95 percent of all cases have occurred there, according to the U.S. Food and Drug Administration.
Humans can contract a form of the disease, called variant Creutzfeldt-Jakob disease, when they consume infected tissue. Cases have proven fatal as recently as this year.
Among animals, mad cow disease is believed to spread when infected animals are turned into animal feed, allowing infected tissue into the food chain.
At the disease’s peak in Britain, there were more than 100,000 confirmed cases. By 1996, the European Union banned British beef exports. The EU ban was lifted in 1999.