Is BSE just a British problem? - bovine spongiform encephalopathy - includes related article about health risks of mad cow disease and Creuzfeldt-Jakob disease

Vegetarian Times, June, 1996 by Mark Harris, Luise Light

Can the disease that literally drives cows mad - and may have killed at least 10 people in Great Britain - show up here? Experts say no, but admit in the same breath that our current surveillance methods and understanding of "mad cow disease" are woefully inadequate to justify any such reassurances.

In March, after the British government acknowledged that tainted beef may have caused the rare brain disorder Creuzfeldt-Jakob disease (CJD) in at least 10 people, the U.S. Department of Agriculture (USDA) scrambled bled to prove that it couldn't happen here. Experts believe CJD may have crossed the species barrier to humans from cows infected with bovine spongiform encephalopathy (BSE), die scientific name for mad cow disease, when the cows were fed scrapie-infected sheep remains as a protein supplement. Scrapie is the form of spongiform encephalopathy that afflicts sheep. The process of feeding sheep car-casses to cows has been outlawed in Great Britain since 1989, but some British experts say that enforcement has been lax.

Nonetheless, die USDA says with confidence that the American beef supply is safe. As a precaution, it also says it will increase the number of brain autopsies performed on cows that exhibit neurological symptoms, and will compel federal al veterinarians to increase their surveilance of die cattle population. In addition, the U.S. Food and Drug Administration promises to draft legislation prohibiting the addition of processed (rendered) animals to meal fed to cows. The practice is still common in this country, despite the presence of scrapie in the U.S. sheep population. According to the USDA, about 7,500 American sheep have the disease.

Such information unsettles many food safety experts, who say the government's reassurances are premature. "They're not even looking for BSE in the right place," says Ronnie Cummins, director of the Pure Food Campaign, a consumer group based in Washington, D.C. He believes American cows harbor a different form of BSE than their European counterparts that may escape current testing methods. He also stresses that die breadth of the surveillance - the USDA has autopsied fewer than 3,000 cows in the last 12 months, a tiny fraction of die total population of 103 million - is woefully inadequate. Other experts point out that BSE, which has an incubation period of up to eight years, may not be detectable in American beef cattle, many of which are slaughtered between the ages of two and five.

Research supports the argument that BSE could threaten American livestock. An alarming 10-year-old study by Richard Marsh, DVM, a veterinary scientist at the University of Wisconsin at Madison, reported that mink fed rendered "downer" cattle developed a form of spongiform encephalopathy. "Downer", cows simply collapse and die for no apparent reason. They cannot be sold for human consumption and are instead processed into feed. Marsh argues that BSE could be the cause of many of these unexplained deaths. Other experiments found that American cattle injected with scrapie didn't go "mad," like their British counterparts, but simply collapsed and died, like thousand of "downer", cows do every year.

Linda Detwiler, DVM, a veterinary scientist with the USDA, considers Marsh's theory inconclusive. That's because, so far, no BSE has been found in "downer" cows here; however, the agency continues to look only for BSE that is similar to the makeup of die British disease. But she agrees that it's too soon to be sure American cattle are safe. "We're looking for a disease that occurs in one of every million cows. It will be very difficult to find with the testing methods we have now," Detweiler says. She adds that increasing die scope of the investigation would be too expensive.

And what about the 499 cattle imported into this country from Britain before 1989? The U.S. government says 343 are dead, and Detwiler says they could have been sent to slaughterhouses for rendering. "Theoretically tainted British beef could have infected American cattle," she adds. The USDA says it cannot account for 35 of the cows, though the agency is planning to incinerate all live cattle imported from Britain in this country.

What does this mean for the health of American consumers? Since British BSE hasn't been detected in American cattle, there's no proof that any American has contracted CJD from eating beef. However, if a different form of BSE is circulating, as Marsh and others believe, the number of CJD cases is certain to rise. The Centers for Disease Control and Prevention (CDC) in Atlanta says the rate of CJD has remained constant in the United States - afflicting about one in a million people. But in Britain, there were 55 cases of CJD in 1994, a 100 percent increase over 1985. Some medical experts think CJD is often misdiagnosed as Alzheimer's disease, which mirrors many of the symptoms of CJD. Because CJD has a latency period of up to 30 years, consumers who ate infected beef in the 1980s may not show signs until the next century. So far, there is no proven cure or test for CJD, though the CDC promises to step up monitoring.