Agriculture officials said Thursday they have received preliminary independent confirmation that the United States has its first case of mad cow disease (search) as federal investigators labored to trace the path the infected cow took from birth to slaughter.
Scientists at the Veterinary Laboratories Agency (search) in Waybridge, England, concur with the reading of tests on the stricken Holstein cow that led U.S. officials to conclude the cow had the brain-wasting disease, said U.S. Agriculture Department (search) spokeswoman Alisa Harrison.
"We are considering this confirmation," Harrison said, adding the English lab still will conduct its own test using another sample from the cow's brain. Final test results on the cow from Washington state were expected by the end of the week.
Meanwhile, Harrison said, investigators were working through the holiday to prevent a potential outbreak of the deadly disease and calm public fears about the nation's food supply.
Government and cattle industry officials voiced assurances that the beef on American Christmas holiday tables was safe to eat.
"The risk to human life is extremely low," Agriculture Secretary Ann Veneman (search) said.
But the biggest buyers of U.S. beef around the world slapped bans on imports of the American product, and there were increasing doubts among a U.S. populace that consumes an average 65 pounds of beef a year. Humans can contract a fatal variant of mad cow disease by eating infected beef products.
"Once I heard that was going on I decided I wasn't eating any more beef or feeding it to my family," said Steve Fairbrother, 44, a disabled former truck driver who was shopping Wednesday for groceries in Montgomery, Ala. "I'm not taking any chances until I hear the government say there's no more of it."
To determine whether there is more, investigators want to find the herd the cow was raised with and what the herd was, since the cow likely was sickened from eating feed made partly from an infected cow. Authorities also want to know where the animals were transported.
USDA chief veterinarian Ron DeHaven said officials had identified two livestock markets in Washington where the animal could have been purchased, but he did not identify them.
Federal and state officials said the Holstein cow's last home was a large dairy operation in southern Washington state where it had been since 2001. Government sources told The Associated Press that the cow came from Sunny Dene Ranch in Mabton, Wash., a town 40 miles south of Yakima.
Authorities also were scrambling to find where the meat cut from the animal was sent. The Agriculture Department already has issued a recall for 10,410 pounds of beef slaughtered Dec. 9 at Vern's Moses Lake Meat Co. in Moses Lake, Wash.
Veneman said the recall was an extra precaution.
Dr. Stanley Prusiner, a neurologist at the University of California at San Francisco who discovered the proteins that cause mad cow disease, told The New York Times he warned Veneman recently that it was "just a matter of time" before the disease was found in the United States.
He said he told her the United States should immediately start testing every cow that shows signs of illness and eventually every single cow upon slaughter, the Times reported in Thursday's editions.
Prusiner told the Times that fast, accurate and inexpensive tests are available, including one that he has patented through his university that he says could add two or three cents a pound to the cost of beef.
The scientist said Veneman is getting poor advice from USDA scientists and did not seem to share his sense of urgency when he met with her six weeks ago, after several months of seeking a meeting.
"We have met with many experts in this area, including Dr. Prusiner," Julie Quick, a spokesman for Veneman told the Times. "We welcome as much scientific input and insight as we can get on this very important issue. We want to make sure that our actions are based on the best available science."
The beef trade quaked at the prospect that the United States had found its first case of the brain-wasting disease. Beef futures trading effectively stopped Wednesday on the Chicago Mercantile Exchange because no one was buying, and restaurant stocks sank.
At least a dozen countries have blocked U.S. beef since the Veneman announced Tuesday that inspectors had found a suspected case of mad cow disease in a "downed cow," meaning it was too sick or injured to move on its own.
Among those banning American beef was Canada, which suffered heavily from a U.S. boycott on Canadian beef when a cow in Alberta was discovered with the disease in May.
Keith Collins, the Agriculture Department's chief economist, said countries that have issued the ban on American beef in the past two days among them top buyers such as Japan, South Korea and Mexico account for as much as 70 percent of U.S. exports.
Last year, the United States exported $2.6 billion in beef.
"So the suspension of sales by those major trading partners ... is going to have a market effect," Collins said. "Where the market will settle out, it's too early to say."
Bovine spongiform encephalopathy (search), popularly known as mad cow disease, is caused by a misshapen protein that essentially eats holes in a cow's brain. Cattle get sick by eating feed that contains tissue from the brain and spine of infected animals. The United States has banned such feed since 1997.
People can get a related disease, variant Creutzfeldt-Jakob (search), if they eat meat that contains central nervous tissue from the brain or spine of a cow infected with mad cow disease, researchers believe. In Britain, 143 people have died of vCJD since a mad cow disease outbreak in the 1980s.
A total of only 153 people worldwide have been reported to have gotten the human form of the illness, according to the federal Centers for Disease Control and Prevention.
Veneman said the U.S. meat supply was safe because the brain and spine were removed from the suspect Holstein dairy cow in Washington before it was sent on for processing.
Keeping those tissues out of the meat supply means the risk of mad cow disease spreading to humans is very slight. So experts say whole cuts like beef steaks and roasts, along with hamburger ground from labeled cuts, such as chuck or round, are safe. They also say that the liver and tongue, as well as dairy products, are safe too.