Mad cow case found in U.S.
|||Hawai'i cattle ranchers in 'wait-and-see' mode|
By Shankar Vedantam
WASHINGTON A Holstein cow slaughtered in Washington state earlier this month was infected with mad cow disease, marking the first time the dreaded illness that devastated Britain's beef industry has been detected in America, officials said yesterday.
Meat from the animal, slaughtered Dec. 9, traveled through three processing plants before a test revealed the problem 12 days later. Officials at the U.S. Department of Agriculture insisted, however, that infectious portions of the animal were removed at the slaughterhouse and diverted to a rendering plant.
"We believe the risk of any human health effects is very low," said Department of Agriculture Secretary Ann Veneman, adding, "I plan to serve beef for my holiday dinner."
But in the first of what may be a cascade of blows to the industry, Japan, the largest foreign customer for American beef, announced a temporary halt on U.S. beef imports, as did South Korea, Australia, Taiwan, Singapore, Thailand and Malaysia.
Officials have clamped a quarantine on the farm in Mabton, 40 miles southeast of Yakima in south-central Washington, that sent the cow to Vern's Moses Lake Meats slaughterhouse in Moses Lake. Agriculture Department officials said they also were investigating three facilities that handled meat from the infected cow, all in Washington state.
Infected tissue samples from the cow were flown by military plane to England, where a laboratory in Weybridge is expected to conduct a final set of confirmatory tests.
Agriculture officials said they had informed their counterparts in Mexico and Canada, but knew of no immediate plans to close borders to the transport of cattle products. The U.S. beef industry slaughters some 40 million animals a year and is worth $175 billion.
The infection bovine spongiform encephelopathy, or BSE turns the brains of animals spongy, and consuming infected meat can cause a related human disease called variant Creutzfeld-Jakob Disease, a fatal brain-wasting disorder. Unlike diseases caused by bacteria or viruses, BSE is caused by a self-replicating protein called a prion.
|Washington Gov. Gary Locke listened to the state agricultural director announce the quarantine of a dairy farm near Mabton, Wash., yesterday.
The disease surfaced in Britain in 1986, where it led to the slaughter of millions of cattle. A total of 153 people are known to have died from the human form of the disease, all but 10 of them in the United Kingdom.
In May, Canadian authorities discovered a case of mad cow in Alberta, leading the United States to suspend imports of Canadian beef. USDA officials said they were investigating whether there the two cases might be linked.
The infected dairy cow in Washington was about 12 years old, said Elsa Murano, undersecretary for food safety. She said the disease is not known to be transmissible through dairy products.
The mad cow disease outbreak in England was traced to brain tissue from infected animals being fed to other cattle. Murano said safety measures in the United States prevent that practice.
Veneman and Murano laid out a chain of events to explain why they believe the nation's food supply is safe. The Holstein cow was sent to the slaughterhouse Dec 9. Since it was unable to move on its own and believed to be at risk for illness, tissue samples were taken after it was slaughtered. Officials did not say precisely why the cow was immobile a so-called "downer" animal but it could have been due to disease, old age or injuries. Scientists conducted routine tests for BSE on some 20,526 cattle in the fiscal year that ended Sept 30.
The brain and spinal tissues of the cow the parts known to be affected by BSE were diverted to a rendering plant, where the tissues were heated and ground up. Murano said the rendering plant might have turned the infected tissue into chicken feed or processed it for the cosmetics industry. Mad cow disease is not believed to be transmitted through those routes.
There is a small possibility that chickens eating the infected meat could have been slaughtered and ended up as cattle feed but the disease has not been shown to be transmissible in that manner, said W. Ron DeHaven, deputy administrator and chief veterinary officer at the Agriculture Department.
Meat from the rest of the infected cow was sent to a deboning plant called Midway Meat and then to two processing facilities, Willamette and Interstate Meat, Agriculture Department officials said.
The first positive test for the infection arrived Monday, DeHaven said, and confirmatory tests were conducted ahead of yesterday's announcement.
A 2001 analysis by the Harvard group found that the Agriculture Department had enough safeguards in place to prevent mad cow disease from spreading widely even if infected cows made their way into the country. For example, it concluded that even if 10 infected animals got into the country, over the next 20 years there would be only four new cases of mad cow disease.
"With this system, the disease would not spread very widely," Gray said.