LANSING, Mich. (AP) — The Michigan Department of Community Health said Tuesday it is drawing some connections in a recent spike in illnesses from E. coli bacteria.

The health department said more than half the Michigan residents affected by the illness report buying and eating ground beef from Kroger Co. food stores.

Health officials say they have genetically linked 15 confirmed E. coli cases in Eaton, Genesee, Macomb, Oakland, Saginaw, Washtenaw and Wayne counties. Ten of those cases involved hospitalization.

At least 17 cases in Ohio also have been linked to this outbreak, Ohio Department of Health spokesman Kristopher Weiss said.

The beef was available in late May and early June in some Michigan stores and in stores in the Columbus and Toledo areas of Ohio and is no longer on store shelves, said Meghan Glynn, spokeswoman for Cincinnati-based Kroger.

"We are working with state and federal investigators to determine the supplier," Glynn said. "Food safety is very important to us, and we take these issues seriously."

Of 24 cases confirmed by the Centers for Disease Control and Prevention, 14 people have been hospitalized and one patient developed kidney failure. People became ill in late May and early June, according to the CDC.

No deaths have been reported.

Symptoms of E. coli infection can include severe stomach cramps, diarrhea, vomiting and fever. Most people recover within 5-7 days.

Health officials urge people to thoroughly cook their hamburgers and, if possible, use a digital thermometer to make sure they've been heated to at least 160 degrees.

They also caution residents to wash their hands with warm water and soap for at least 20 seconds before and after handling food.