USDA officials believe some of the meat from a cow infected with Mad Cow Disease wound up in Alaska, Hawaii, Idaho, Montana, and the U.S. territory of Guam, in addition to the four states originally on the recall list: Washington, Oregon, California, and Nevada.
Officials continue to insist the risk to consumers is low, because the parts known to carry the disease, including the brain and spinal cord, were removed before processing.
"The recalled beef presents an essentially zero risk to American consumers," said Dr. Kenneth Peterson, a USDA Veterinarian.
So far, USDA officials have not definitively pinpointed where the infected cow came from, but their preliminary information tracks the animal to Alberta, Canada, where it was imported to the U.S. along with a herd of 73 others more than two years ago. But Canadian officials say it's still too early to talk about any definite links.
"Based on our understanding of the information compiled to date, it would be premature to draw such conclusions at this time," said Dr. Brian Evans, Canadian Food Inspection Agency.
The USDA says ear tags were used to track the cow, and officials are in the process of trying to conduct DNA tests to confirm its origins. The Mad Cow scare has prompted at least one lawmaker to call for better tracking of the nation's beef supply. In a statement Senator Chuck Schumer aid U.S. officials were caught unprepared.
"How much more of a wake-up call could we possibly need? We need a comprehensive way to track tainted meat and to pull it off the shelves," said Schumer.