Further testing is under way to determine if the strain of the bacteria matches the strain found in 15 central Ohio people, nine people in Michigan and two people elsewhere in Ohio.
The total number of central Ohio cases is now 17.
Union County — where one case now has been reported — has joined the group of central Ohio health departments investigating the outbreak locally. Those include health officials in Columbus and Delaware, Fairfield and Franklin counties.
The Michigan Department of Community Health, the Centers for Disease Control and Prevention and the U.S. Department of Agriculture also are involved.
Seven people in central Ohio have been hospitalized and illnesses have been found in everyone from toddlers to the elderly. There have been no deaths.
People infected with E. coli O157:H7 typically have abdominal cramps and diarrhea, which can be bloody and severe, and may appear 2-8 days after infection. Individuals who have experienced symptoms should consult their doctors.
To prevent transmission, cook meats thoroughly, wash hands often and scrub fresh fruits and vegetables.
Ground beef should be cooked to 160 degrees. Do not eat ground beef that is pink in the middle. If a restaurant serves you undercooked ground beef, send it back for recooking and ask for a clean bun and plate.