ATLANTA – Investigators with the Centers for Disease Control and Prevention (C.D.C.) and the Food Safety and Inspection Service (F.S.I.S.) of the U.S. Department of Agriculture (U.S.D.A.) identified ground beef as the source of an outbreak of E. coli O103 illnesses affecting 109 individuals in six states.

The C.D.C. said case patients reported eating ground beef at home and in restaurants. However, investigators have not identified a common supplier, distributor or brand of ground beef as the source of the outbreak strain. Traceback investigations are ongoing, the agency said.

Illness onset dates range from March 2 to March 26. Two deaths have been reported, but 17 people have been hospitalized.

Symptoms of an E. coli infection can include severe stomach cramps, diarrhea and vomiting. Some people may have a fever, which usually is not very high — less than 101˚. Roughly 5% to 10% of people are diagnosed with hemolytic uremic syndrome (HUS), which is a potentially life-threatening illness. Most people with HUS, recover within a few weeks, but some individuals can suffer permanent damage or die.