State health officials and the U.S. Centers for Disease Control and Prevention (CDC) say at least 26 people are now believed to have become ill after consuming contaminated beef products produced by ConAgra Foods Inc. The announcement comes just days after the U.S. Department of Agriculture (USDA) ordered ConAgra to recall nearly 19 million pounds of ground beef after 18 people became ill from eating meat contaminated with the bacteria Escherichia coli.

According to the company, the recalled beef, made at its Greeley, Colorado plant between April 12 and July 11, was shipped to 21 states. So far, the illnesses have been isolated to five states-Colorado, Michigan, South Dakota, Washington and Wyoming. A CDC researcher, however, said the number of cases would most likely rise. Dozens of similar illnesses linked to the tainted beef are now under investigation.