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Two stories from tomorrow's New York Times

Inspections for Mad Cow Lag Those Done Abroad

In discussing the case of mad cow disease apparently found in Washington State, Secretary of Agriculture Ann Veneman said yesterday that her department had tested 20,526 cattle for mad cow disease last year. But that is only a small percentage of the 35 million commercially slaughtered each year.

Because no domestic cases of mad cow disease have been found before, the United States has never put in place the kind of stringent testing done in Japan and some European countries, where every animal is supposed to be tested before humans can eat it.

Inspectors are supposed to view cattle outside slaughterhouses and weed out any having trouble walking. Those with signs of brain disease are to be ruled unfit for human consumption and sent to a rendering plant.

That appears to have happened with the Washington cow. Yesterday, Elsa Murano, under secretary of agriculture for food safety, said its brain and spinal column had been sent to such a plant, to be turned into protein feed, oils and other products. It is the brain and spinal cord that are the most likely to be infected with prions, the misfolded proteins that can lead to a mad-cow-like disease in humans.

This does not guarantee that infected matter will never make its way into the human food supply, critics noted yesterday.

Under Food and Drug Administration regulations issued in 1997, it is illegal to feed protein made from cows, sheep, deer and other so-called ruminants to other ruminants. But it is still legal to feed the rendered protein to pigs, chickens and other animals. Those animals in turn can be rendered and fed to cows or sheep. Also, beef blood and beef fat can be fed to calves.

"You can go into any feed store and buy Calf Starter or calf milk substitute," said John Stauber, co-author of "Mad Cow U.S.A." a 1997 book that warned that the disease could reach this country. "We're weaning calves on cattle blood proteins, even though we know blood plasma can carry the disease."

Also, said Sheldon Rampton, Mr. Stauber's co-author, questions have been raised about how effective the F.D.A. bans on feeding across species are.

If an animal becomes infected, the incubation period of the disease is between three and eight years, so the detection of one animal with the disease suggests that others may have been infected by the same source but have not yet been found.

Mr. Stauber said an F.D.A. memo written in 1997 predicted that if a single case of encephalopathy was found in the United States and a total ban on all feeding of animal protein to animals immediately enacted, it was still possible that as many as 299,000 infected cows would be found over the next 11 years.

In the past, the hooves and horns were used for gelatins and bone and blood meal as fertilizer and the fat became soap. But with the invention of chemical soaps and fertilizers in the 1960's, other uses had to be found for the waste, and the animal protein market developed as a cheap way to bulk up animals.

Danger to the Public Is Low, Experts Say
ven if beef from one infected cow got into the food supply, the chances that any consumer would develop mad cow disease are extremely low, experts on the disease say.

"One can derive a fair bit of comfort from statistics and epidemiology," said Dr. Fred Cohen, a professor of pharmacology at the University of California at San Francisco who is an expert on mad cow disease. "Put the question into context. When there were 60,000 to 80,000 infected cows in the U.K., approximately 150 people out of 60 million developed the disease." Here in the United States, Dr. Cohen said, "one cow is not likely to translate into any cases."

The primary safety concern is to avoid eating any nervous system tissue from an infected animal.

The Department of Agriculture says that whole cuts of beef — steaks, chops roast — are generally safe to eat because mad cow disease is not known to affect the muscle meat. The disease occurs in the central nervous system of the animal.

Critics of the Agriculture Department, who say the agency has resisted taking the steps needed to keep mad cow disease out of the food supply agree that muscle meat is safe but offer more specific steps the public can take to protect itself.

Caroline Smith DeWaal, director of food safety for the Center for Science in the Public Interest, said a consumer should:

• Avoid ground beef unless they grind it themselves from a whole piece of muscle meat.

• Avoid brains, beef cheeks, neck bones.

• Avoid any meat that comes from the head and any meat that is taken from close to spinal column or containing bone that is part of the spinal cord, like T-bone, which was banned in some European countries during the outbreak in Britain.

• Avoid pizza toppings, taco fillings, hot dogs, salami, bologna and other products that contain not only ground beef but beef from machinery that squeezes out bits of meat that cling to the spinal column and other bones.

In a survey conducted in 2002 by the Agriculture Department, products for 34 processing plants that use such machinery, known as an advanced meat recovery system, were tested and 35 percent of them tested positive for central nervous system tissue.

Mad cow disease, or bovine spongiform encephalopathy, is caused by a protein, called a prion, that folds itself into an abnormal shape that has several lethal properties. When a misfolded prion comes into contact with a healthy prion, it can cause the healthy proteins to misfold as well, starting a deadly chain reaction.

The abnormal prions form clumps that kill brain cells, leaving holes. Brain and nervous tissue are destroyed, resulting in death.

Then, if a healthy human or animal eats meat or processed foods contaminated with misfolded proteins, the disease can take hold. The dose needed to cause an infection, however, is not known.

Animals can contract B.S.E. in two ways. Most commonly, they get it from eating feed that has been contaminated by infectious prions. They can also develop the disease spontaneously when a normal prion mutates and starts the chain reaction, a process that leads to spontaneous infection in an estimated one in a million cows, deer and other mammals.

Infectious prions enter the body through the gut and are passed to the brain through lymph and other immune cells. They are found mostly in the brain but can exist for quite some time in peripheral tissue like tonsils, appendixes and lymph nodes in muscle. Misfolded prions have also been identified in white blood cells, a fact that led blood banks to ban blood donations by people who lived in Britain at the height of the epidemic.

Prion diseases go by many names. The sporadic form of the disease in humans is called Creutzfeldt Jakob Disease or C.J.D. When people contract it from eating infected beef, the disease is called variant C.J.D. In deer and elk it is chronic wasting disease.