At least 156 people in 10 states have been infected with E. coli after eating tainted ground beef at home and in restaurants, federal officials said.

Of the people infected so far, 20 have been hospitalized, the Centers for Disease Control and Prevention said Tuesday. No deaths have been reported.

The cases include people who've eaten the beef since March 1, the agency said, but no supplier, distributor or brand of beef has been identified.

"Traceback investigations are ongoing to determine the source of raw ground beef supplied to grocery stores and restaurant locations where ill people reported eating," the CDC said.

People fell ill starting March 1, the agency said. Those infected range in age from younger than 1 to 83 years old, with a median age of 19.

"Illnesses that occurred after March 26 might not yet be reported due to the time it takes between when a person becomes ill with E. coli and when the illness is reported. This takes an average of two to three weeks," the CDC said.

The CDC earlier this month said it had identified ground beef as the food responsible for an outbreak that at the time involved 109 cases of illnesses in six states.

The outbreak has now expanded to include: Georgia, Kentucky, Ohio, Tennessee, Virginia, Indiana, Florida, Illinois, Mississippi and Minnesota.

Meanwhile, Colorado Premium Foods recalled more than 113,000 pounds of raw ground beef products due to possible E. Coli contamination, the Food Safety and Inspection Service said Tuesday in a statement. The Georgia company said the ground beef items were produced on March 26 and 29, and on April 2, 5, 10 and 12.

There's no established link between the product and the ongoing E. coli outbreak, according to the statement.

Symptoms of E. coli infection include severe stomach cramps, diarrhea and vomiting. They begin, on average, three to four days after ingesting the bacteria. Most people recover in five to seven days.

Consumers are urged to prevent the spread of E. coli by washing hands, cooking ground beef to an internal temperature of 160 degrees and keeping uncooked foods away from raw beef to prevent cross-contamination.