• Food safety: Failing the test Food safety: Failing the test From the St. Louis Post-Dispatch January 25, 2005 A disease. how study conducted on mice in Switzerland illustrates much we have yet to learn about the proteins called prions,
• Food safety: Failing the test
Food safety: Failing the test
From the St. Louis Post-Dispatch January 25, 2005
A disease. how study conducted on mice in Switzerland illustrates much we have yet to learn about the proteins called prions, which are thought to cause mad cow That has important implications for the nation’s inadequate food safety system. The system already was under fire before the study.
Now, with the Bush administration poised to once again allow imports of Canadian beef, and the discovery of two more infected cows in Alberta, the need to make improve-ments is even greater. The idea that bits of protein could cause disease was controversial until about a decade ago.
Since the recognition in 1996 that humans had become infected from eating tainted meat, researchers have made major strides understanding these puzzling illnesses. Based on post-mortem tests, scientists had believed that prions were present only in the nervous system of in-fected animals.
As a result, the United States and other countries required that the brains, spinal cord, and other tissue be removed from animals used for food. But the Swiss research, published this month in the journal Science, showed that prions follow immune cells in the body. When mice were given chronic diseases, then injected with prions, the prions made their way to various organs.
Animals with obvious signs of infection aren’t allowed into the food supply. However, sloppy inspections or less obvious infections could let such beef go undetected. Ani-mals are thought to become infected by eating feed with contaminated animal proteins. Since 1997, it has been il-legal in both Canada and the United States to feed animal proteins derived from cattle to beef cattle. But it remains legal to feed such proteins to chickens and pigs, then use those animals – or, in the case of poultry, their droppings – in cattle feed. That’s a bad idea, because prions remain infectious even in the bodies of animals that can’t get mad cow disease.
The U.S. Department of Agriculture relies on the 1997 feed ban to prevent new mad cow infections. But one of the infected cows discovered this month was born after 1997, raising questions about the ban’s adequacy. Cattle are natural herbivores. It’s time to ban all animal proteins from cattle feed. Both the National Cattleman’s Beef As-sociation and the National Grain and Feed Association regard tightening the feed ban as an animal health issue. Human health is protected by the removal of “specified risk material,” brains, spinal cord and other tissue, from animal carcasses, the Cattleman’s association says. Nei-ther group said it had studied the cost of changing the feed rules.
The Bush administration should rethink ending the import ban. That would help consumer confidence, but it won’t protect consumers; the same ranching practices used in Canada also are used here. If Canada has a mad cow problem, we have a mad cow problem.
The USDA has stepped up testing for mad cow disease, but it’s still only testing about 20,000 high-risk animals a year. France, which has a much smaller beef industry than the United States, tests more than 2 million animals. In order to detect mad cow disease at a rate of one case per 1 million cows – the rate at which a related prion ill-ness called Creutzfeldt-Jacob Disease exists in the human population – the USDA would have to test 3 million cattle. That would cost much more than testing just 20,000 ani-mals, but it potentially could protect the beef industry, not to mention beef consumers, from catastrophic harm. The USDA should do so immediately.
There’s an awful lot we still don’t know about mad cow disease. But what we do know is enough to suggest our food safety system is inadequate to protect consumers.
