The U.S. Centers for Disease Control and Prevention reported on Tuesday that a connection was established between the eruptions of E. coli bacteria in Michigan and Ohio. Health officials in both states believe the outbreak was set off by ground beef.

Health officials in Michigan informed the press that more than half of the people with confirmed E. coli cases admitted to having purchased ground beef from Kroger Food Stores, the largest U.S. grocery chain.

Kroger spokeswoman Meghan Glynn stated in an e-mail that she was aware of the fact that the E. coli illnesses were linked to the products purchased in their company’s stores. She added that the outbreaks were reported between May 30 and June 8 and that “any ground beef sold during that period is no longer available in our stores.”

However, the health officials were not able to detect up to this moment the exact type of ground beef that caused these illnesses and its supplier. “We purchase our ground beef from major suppliers in the industry and we are working with federal, state and local agencies to identify the supplier,” Glynn said.

The Centers for Disease Control confirmed on Monday more than 20 cases of E. coli that revealed the same genetic fingerprint and features, pointing to the fact that they are connected. Out of the 24 cases, 11 had been reported in Michigan and the other 13 in Ohio.

A spokesman for the Ohio health department, Kristopher Weiss, informed the reporters that the number of cases in Ohio had raised to 17 and the state was inspecting two supplementary possible cases.

Kroger is collaborating fully with health officials and federal investigators. However, officials are still examining the situation and said other grocery outlets may be discovered.

The Centers for Disease Control reckons that there may be about 70,000 contaminations with E. coli each year in the United States, but many of those infected people do not seek medical care.