The man at a dinner party leans over and asks: "Are you worried about 'mad cow' disease? Should we stop eating steak?"

I laugh. Earth to Chicken Little! The sky is not falling on steak. Not here, anyway. Of all the things to worry about, getting mad cow disease from a nice juicy filet mignon is not one of them. Not yet, anyway.

I go through the obvious arguments.

Not a single case has occurred in the United States in man or beast. Precautions are in place to prevent the disease from spreading to this country. Feed made from certain animals -- the suspected culprit in Europe -- is prohibited here. Beef and beef products from affected countries are banned. Even in Europe, fewer than 100 people have succumbed to the strange malady since the outbreak began four years ago. Those cases have been confined to Britain, Ireland and France where -- statistically speaking --

people are five times more likely to be killed by a bolt of lightning than by mad cow disease.

If you're going to worry about what you eat, there are bigger food-borne killers. For starters, listeriosis (from contaminated meats, dairy products, raw vegetables) and salmonella (from contaminated raw eggs) each cause 500 deaths a year in this country. E-coli, which is most associated with eating contaminated ground beef, kills 61 people a year. Why worry about something that hasn't killed anybody in this country?

The expression on the dinner guest's face goes from polite disagreement to pity. I must sound like a victim of "Animal Farm" propaganda from the agri-medical establishment. He doesn't believe a reassuring word I've said.

Why should he? Europe is in a panic over mad cow disease. Overall consumption of beef dropped 27 percent from October to December. The cattle industry has been crushed and governments are shaken. Instead of promoting the national staple of le steak et pommes frites, French farmers are throwing stones at their prime minister.

The fear is spreading to these shores: Cattle in Texas quarantined after eating bone meal. Elk in Oklahoma diagnosed with a chronic wasting disease. Suspect mad cow candy on sale in New York City.

Mamba fruit chew, banned in Poland, is made with a beef-based gelatin produced in Germany, where about 20 cows have been found to be infected with bovine spongiform encephalopathy (BSE), the scientific name for mad cow disease. In the ensuing public-relations meltdown, the company announced it would switch from beef gelatin to vegetable starch.

Call that Mad Cow Panic Syndrome (MCPS) Tests have shown that the disease cannot be transmitted in gelatin, even from infected cattle, says George Gray, director of the program for food safety and agriculture at the Harvard School of Public Health's Center for Risk Analysis in Boston. "It's a nonissue," he says. "This situation takes on a life of its own."

The perception of risk is wildly out of proportion to the actual risk.

"When I have a hamburger, I worry much more about E-coli than a chance of BSE," Gray says. Even if an animal in the United States shows up sick one day, there would be no immediate threat to people. Tightened surveillance would prevent the spread to other animals and keep the infected animal from reaching the human food chain. "It's not going to be a big public health risk," Gray continues. But if that day comes, he adds, "we'll go bonkers."

Mad cow bonkers. All of us from Henny Penny to Goosey Loosey have a hard time dealing with risks. Certain kinds of hazards, no matter how rare, grab our imagination so that we fear the worst. They usually share these characteristics:

Mysterious. Just what causes mad cow disease is not known. The prime suspect is a prion, an aberrant protein that attacks the central nervous system. Scientists are used to bacteria and viruses, but prions are a new kind of infectious agent. The theory is that herds in Britain were infected from contaminated bone meal. BSE crossed from animals to people, causing a variant of the rare degenerative brain disorder called Creutzfeldt-Jakob disease. There is no evidence, points out Harvard's Gray, that the prions get into muscle meat -- in other words, into steak. Greatest concern is focused on brain and bones and mixed meats such as sausage.

Lethal. The disease is horrible and invariably fatal. About 300 Americans die of the classic form of Creutzfeldt-Jakob disease a year, which strikes seemingly at random. There is no effective treatment. With listeriosis, for example, an estimated 2,500 Americans get very sick, but they can be treated with antibiotics and most of them recover. Mad cow disease is a death sentence, and victims are generally younger than those who succumb to the classic form of the brain malady.

Unpredictable. The infection in cattle peaked in 1993. Since then, Britain has slaughtered infected herds and tested cattle to make sure they are healthy. Last year, the European Union banned the use of remnant parts in animal feed to reduce the chances of contamination. At the same time, the incubation period in people for this disease could be anywhere from two to 20 years. Health officials don't know if the number of cases will level off. Or whether the current toll represents the tip of an epidemic iceberg of many more people who harbor the infection. "We don't know how many people are infected. We don't know the size of the risk," says psychologist Baruch Fischhoff of Carnegie Mellon University.

There is not a lot people can do to reduce their personal risk.

You can avoid lightning by staying indoors in a thunderstorm (about 300 deaths in the United States annually) and prevent head injuries on a bicycle by wearing a helmet (about 800 deaths a year). You can avoid salmonella by cooking eggs and listeriosis by sticking to pasteurized cheese.

But it's hard to control your exposure to all the theoretically possible avenues to mad cow disease -- even when there is no evidence of a problem. Just last week, the headlines screeched that five major drug companies had used ingredients from cattle in affected European countries to manufacture vaccines given to millions of American children -- contrary to recommendations of the FDA. Animal-based gelatin is also used in supplements with little government oversight.

The prions are falling! In a world of medical globalism, neither diseases nor drugs recognize national boundaries.

To date, mad cow disease is not a crisis in public health; but it's becoming a crisis in public trust.

Washington Post Tuesday, February 13, 2001; Page HE08