18.6 million pounds of ground beef recalled

WASHINGTON (CNN) -- Federal health officials announced Friday the recall of 18.6 million pounds of potentially contaminated ground beef blamed for at least 16 cases of illness in Colorado.

Six additional cases that might be related have also been identified in South Dakota, Washington state, Wyoming, Michigan and California, the Centers for Disease Control and Prevention said.

"This action is being taken as a cautionary measure to ensure the protection of public health," said Secretary of Agriculture Ann Veneman. "Public health is our number-one priority, and it is our number-one concern."

No one has died, and no one is currently hospitalized as a result of the E. coli 0157:H7 bacteria contamination in meat processed at the ConAgra Foods Inc. plant in Greeley, Colorado, federal health officials told reporters.

Dr. Elsa Murano, undersecretary for food safety, said the beef was processed from April 12 to July 11 and that she had "no idea how much product is still in consumers' hands."

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A random test taken April 12 first picked up small positives for E. coli, but they were not considered serious enough to mandate a recall, Murano said. It was not until June 19, when a customer reported a positive test for the bacteria on meat from the plant, that an investigation began, she added.

On June 30, 154,000 pounds of ground beef were recalled.

Since July 11, 30 USDA inspectors have been inspecting all of the beef processed at the plant and no more contaminated meat has been found, Murano said.

She urged consumers who have bought suspect meat to return it to the point of purchase or discard it, or to call the department's meat and poultry hotline at 800-535-4555 or look at its Web site: www.usda.gov.

USDA investigators are working with company officials, scientists, the CDC and the Colorado State Department of Health in the ongoing investigation, Veneman said.

Friday's voluntary recall is national. Though the suspect beef was sent to customers in 21 states, some of them sent it on to other states.

ConAgra processes beef from 23,000 head of cattle each day. The recalled beef was processed in late May. Typically, E. coli causes illness five to 10 days after it is eaten.

The E. coli bacteria are blamed for an average of 61 deaths and 73,000 cases of illness annually in the United States, officials said.

The illness can be prevented simply by cooking infected beef thoroughly by raising its temperature to 160 degrees.

Much of the recalled beef may already have been eaten.

Friday's announcement marks the second-largest such recall in U.S. history. In 1997, officials recalled 35 million pounds of ground beef processed by Hudson Foods after 15 people in Colorado were sickened by the bacteria.

-- CNN Correspondents Kathleen Koch and Rea Blakey contributed to this story.