Study Finds Broader Reach for Mad Cow Proteins - NYT 1/21/05

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Just when they thought they were safe by not eating cow brains...

 

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Study Finds Broader Reach for Mad Cow Proteins

 

January 21, 2005

By SANDRA BLAKESLEE

 

 

 

Mad cow disease has long been thought to occur in just the

brains and nervous systems of infected animals. But

scientists are reporting today that the proteins thought to

cause the disease can travel to other organs as well.

 

 

The research is based on experiments with mice, but if it

is borne out in other species, it may suggest that no part

of an infected animal is safe to eat. The disease leads to

a fatal brain infection in humans.

 

 

In the mouse experiments, reported in the journal Science,

researchers in Switzerland found that prions, proteins that

are the infectious agent in mad cow disease, follow immune

cells, called lymphocytes, in the body. When mice were

given chronic infectious diseases of the liver, kidney and

pancreas and then inoculated with prions, the prions made

their way to the infected organs.

 

 

Dr. Adriano Aguzzi, a neuropathologist at the University

Hospital in Zurich, who led the experiments, said this

meant that cows and sheep infected with prions could harbor

the disease in any inflamed organ.

 

 

But Dr. David R. Smith, a veterinarian at the University of

Nebraska, said the research did not raise alarms about

American beef. For one thing, he said, livestock with

obvious signs of systemic infection, like a fever, are not

allowed into the food supply. And most American cattle are

slaughtered while they are young and at reduced risk of

infection.

 

 

Many countries, including the United States, require the

removal of skulls, brains, eyes, spinal cords and other

nervous tissues from slaughtered animals because prions are

known to accumulate in those tissues. Even in countries

with mad cow disease, mainly in Europe, meat is considered

safe if those tissues are removed, Dr. Aguzzi said. But the

disease could spread more readily if infections are not

obvious or if inspections are sloppily done, he said.

 

http://www.nytimes.com/2005/01/21/national/21disease.html?ex=1107363860&ei=1&en

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