WASHINGTON - February 19 - The U.S. Department of Agriculture (USDA) has misled the public about the effectiveness of its approach to prevent mad cow disease in the United States, Peter Lurie, M.D., deputy director of Public Citizens Health Research Group, told the USDA today. In a letter to USDA Secretary Ann Veneman, Lurie said that in a number of crucial areas, the agency has overstated the impact of new rules, falsely reassuring the public.
The USDA has repeatedly claimed that its testing and surveillance system has been able to detect bovine spongiform encephalopathy (BSE), also known as mad cow disease, if it occurs in one in a million cattle. That claim is false, Lurie said, because it rests on an assumption the USDA knows is incorrect: that BSE exists only in downer cows (those cows that are too sick to walk).
Data from Europe show that although the BSE risk is higher in downer cattle, hundreds of animals that appear normal have also tested positive for BSE. But, because there are so many more normal-appearing cattle than downers, there is more overall BSE risk among normal cattle than among downer cattle. Using a statistical analysis, Lurie showed that removing all downer cows from the food system, as the USDA has now done, cuts out only 12 percent of the total BSE risk.
Moreover, on Tuesday, the U.S. House Committee on Government Reform questioned whether the cow with BSE that was discovered in Washington state in late 2003 was really a downer, as the USDA has repeatedly claimed. The USDA will have to test a mix of downer and non-downer animals to truly detect the one in a million risk, Lurie wrote.
"Removing downer cattle from human consumption was appropriate, because the animals are more risky," Lurie said. "But the overall risk to the public was only slightly reduced, and the benefit to the publics safety has been oversold."
Lurie also questioned the overall effectiveness of the USDAs decision to permit use of advanced meat recovery (AMR) only in cattle younger than 30 months. AMR uses belts and bone presses to remove the last scraps of meat from a carcass and is risky because the muscle tissue it retrieves is often contaminated with nerve tissue that is the most infectious part of a BSE-affected animal.
Although the USDA presents this new restriction as a food safety issue, in reality all the agency has done is change the labeling requirements. The USDA has ruled that products that have been retrieved by AMR from younger cattle and are contaminated with spinal cord cannot carry the designation "meat." However, the rules permit this product to be called "beef," so it is conceivable that beef stock, extract and flavoring could contain spinal cord.
The agencys rules also still allow unprocessed spinal cord or brain from cattle under 30 months to be sold as food for humans. Lurie recommended a total ban on such products, or at minimum that they be clearly labeled and that consumers be warned of the risk of BSE.
"The USDAs response to the recent mad cow case has been characterized at least as much by concern for the beef industry as it has been by concern for public health," Lurie said. "It is time for the USDA to come clean with the American public."
Both Lurie and Sidney Wolfe, M.D., director of Public Citizens Health Research Group and a co-signer of the letter, are former members of the U.S. Food and Drug Administrations advisory committee on BSE. Click here to view a copy of their letter.