Agencies work to keep mad-cow disease out of U.S. pastures

"Mad-cow disease" is a phrase that often evokes wisecracks. Europe has had to shoulder huge financial losses from the disease's devastating effects, but the image of a frenzied cow shaking and mooing uncontrollably still elicits chuckles, even there. In fact, crazy-cow miniature toys were all the rage in France last Christmas.

Mad cows, however, are no laughing matter for the U.S. officials who are charged with maintaining animal health and food safety. Their job is to keep out the disease that has been responsible for the deaths of hundreds of thousands of European cows and, scientists believe, almost a hundred people.

Indeed, U.S. officials have their work cut out for them. In January, about 1,000 Texas cows were quarantined after officials discovered they might have eaten animal feed banned because of its links to mad-cow. And in March, federal agents seized a flock of sheep in Vermont that had been quarantined for two and a half years because some of the sheep showed signs of having a brain disease related to mad-cow.

Here's some background: The technical name for mad-cow disease is bovine spongiform encephalopathy, or BSE. It's part of a little-understood group of diseases called transmissible spongiform encephalopathies, or TSEs, which are characterized by the way they create spongelike holes in the brain. TSEs are rare, but they are found in a number of species.

Scientists discovered mad-cow 15 years ago in Britain. The number of affected cattle grew, peaking in 1993 at 1,000 new diagnoses a week. The outbreak, of course, wreaked havoc on the beef industry. But the real problems for beef producers didn't start until 1996, when the British government released a report linking mad-cow to 10 human deaths.

Scientists compared the symptoms of these 10 people with those caused by Creutzfeldt-Jakob disease, a rare human TSE that occurs in one in a million people a year worldwide. But unlike Creutzfeldt-Jakob victims, who usually are age 55 or older, these 10 were much younger, some even in their teens.

Scientists decided their illness was a new, separate TSE they dubbed "new variant Creutzfeldt-Jakob" disease, or vCJD for short. Like the classic Creutzfeldt-Jakob, vCJD destroys the brain and is invariably fatal. It has an exceptionally long incubation period, lasting from five to 20 years.

Researchers soon found evidence that those who died of vCJD had gotten it by eating beef tainted by mad-cow disease. The European Union banned British beef exports for three years. The market for beef plummeted.

The majority of cattle that have succumbed to mad-cow have been from Britain, but cases have also cropped up in about a dozen other European countries. As of early February, 98 people have been diagnosed with vCJD-94 from Britain, three from France, and one from Ireland.

How does mad-cow spread, and how did it get into the meat sold in grocery stores and restaurants? The most likely explanation isn't for the faint of stomach. After cows are sent to slaughter, the meat is removed and the leftover scraps, such as bones, hooves, and organs, are cooked and melted in a process called rendering. This stew is then added to animal feed. Issues of cow cannibalism aside, proponents of rendering call it an efficient way to give cattle protein and to use all of the leftover bits from a slaughtered cow.

The mad-cow agent (it's not exactly a virus or bacterium) is thought to reside mainly in the bovine brain or spinal cord. Researchers believe that the brains and spinal cords of infected cows were mixed into feed given to other cows, thereby spreading the disease. Parts of the infected cows could also have made their way into the human food chain, causing vCJD.

Mad-cow disease and vCJD have never been found in the United States. The Agriculture Department and the Food and Drug Administration--as well as officials from U.S. Customs, the Centers for Disease Control and Prevention, and other agencies--have teamed up to try to keep the disease out.

The USDA has been relatively ahead of the game on imports. In 1989, the United States became the first country to ban the importations of live ruminant animals--those that chew a cud, such as cows, goats, and sheep--and ruminant products from countries where mad-cow had been discovered. The department expanded the ban in 1997 to include all European countries, regardless of whether they had the disease.

The FDA also did away with cow cannibalism in 1997, banning farmers from feeding to ruminants animal protein that is derived from ruminants and most mammals. In December, the USDA prohibited the import of all rendered protein from all European countries. And the FDA has forbidden blood donations from anyone who spent six months in Britain between 1980 and 1996.

Three studies--one done by the USDA in the early 1990s, one done last year by the European Union, and one to be released in June by Harvard University--predict that the risk of mad-cow showing up in the United States is slight. But because so little is known about the disease, it can't be written off, said Linda Detwiler, a senior staff veterinarian at USDA's Animal and Plant Health Inspection Service.

The USDA performed 11,954 cattle inspections from 1990-2000. (Officials must euthanize the cows to check their brains for BSE.) But critics say this number is not enough. "We do think that the government could do more," said Peter Lurie, deputy director of Public Citizen's Health Research Group. The USDA's goal is to increase the number to 5,000 cattle inspections annually, and to do them at more locations.

Lurie estimates that less than 1 percent of products subject to FDA rules are physically inspected at U.S. borders. Stephen Sundlof, the director of the FDA's Center for Veterinary Medicine, acknowledged that only a small percentage of imported products are physically inspected, but he said that records of all products that can contain material related to mad-cow, such as live animals, animal feed, and food products, are checked. Problems can arise, however, "if a substance is misdeclared, either accidentally or intentionally. Then the chance of it being picked up in a routine inspection is relatively rare," he said.

The FDA plans to increase the number of inspectors at the ports and at feed mills, Sundlof said. In January, the FDA revealed that in a two-year inspection of more than 9,100 feed firms, close to 1,700 firms were not even aware of the 1997 feed ban. Of the firms that handled prohibited material, 28 percent did not include a label on their products cautioning that the feed should not be given to cows or other ruminants. Since then, more firms have been inspected and more have complied with the rules.

Lurie and others have also questioned certain meat-processing methods and practices that could cause brain and spinal cord tissue to enter the meat supply. One practice that has already been reformed is the use of pneumatic stun guns.

Researchers found that the guns, which beef producers use to put down cattle before slaughter, sometimes caused bovine brain matter to go into other parts of the cow's body. This happened less than 2 percent of the time, according to a study funded by the National Cattlemen's Beef Association and the American Meat Institute. But the risk was enough to cause beef producers to reconsider using the stun guns, said Gary Weber, the beef association's executive director of regulatory affairs. "In a very short amount of time, the [beef] companies stopped using them, and the manufacturers stopped making them and offered alternative products," he said.

Cow parts aren't used only in animal feed. They're found in more places than people realize, from soap to sweets to sporting goods. A small number of dietary supplements use cow brain and glandular material, Lurie said. But the FDA hasn't been able to regulate them since the Dietary Supplement Health and Education Act became law in 1994. "Dietary supplements are the Wild West out there at this point," he said.

Some vaccines--such as polio and diphtheria, tetanus, and pertussis (DTP), which are required for children to enter many public schools--also use bovine material such as cow blood. Since 1993, the FDA has issued a couple of guidance letters asking vaccine companies not to use material from cattle raised in countries at risk of mad-cow disease. But the FDA found out last year that at least five companies had not complied.

Still, government officials decided not to pull the vaccines off the market because the chances of anyone getting a mad-cow-related disease are "remote and theoretical." Lurie concurred, but said the Bush Administration should take a stricter, better-safe-than-sorry approach.

Europe's mad-cow crisis hasn't lowered demand for beef in this country. But the impact would be devastating if mad-cow were to be discovered in American cattle, Weber said. "It only takes one case," he said. "Beef purchases would probably go down between 30 and 50 percent." Think of it this way, he said: Every 1 percent of consumer demand equates to about $350 million a year just in farm and ranch income. A 30 percent decline in demand would mean a loss of $10.5 billion to the beef industry.

Because of the level of uncertainty surrounding mad-cow, and because of the 100 percent fatality rate of its human counterpart, vCJD, mad-cow disease will continue to be a hot-button issue. Federal officials, meanwhile, will continue to judge their success on the number of mad cows found in the United States: zero.