Public health officials have identified the source of the E.coli outbreak that has sickened at least 24 people in Michigan, mostly in the southeastern part of the state. The Michigan Department of Community Health announced that iceberg lettuce from a Detroit-based produce distributor was the probable source of the statewide E. coli outbreak.

The lettuce distributed by Aunt Mid’s Produce Co was linked to more than 30 Illinois cases of E. coli, the Illinois Department of Public Health said. The Illinois Department of Public Health is warning consumers to stay away from Aunt Mid’s products.

The people became sick after eating iceberg lettuce distributed by the Detroit-based company between the end of August and mid-September, health officials said.

The company has voluntarily suspended the processing and sale of bagged lettuce throughout the United States, the department said.

Seven cases have been reported at Michigan State University, five among prisoners at the Lenawee County Jail, three in Macomb County, other three at the University of Michigan; two have been reported in Wayne County and one case per St. Clair and Oakland County.

Esterichia coli is a common bacteria found in the human digestive tract. Some strains, such as the E.coli O157:H7 strain can cause bad stomach cramps, vomiting, diarrhea, sometimes with blood in it. In some cases, it can cause life threatening problems. Children, the elderly and people with weak immune systems are more exposed to the disease. The negative health effects of E. coli can remain for months and years later.

Outbreaks have been associated with undercooked ground beef (used for hamburgers), vegetables grown in cow manure or washed in contaminated water.