Do you know where the E.coli outbreak is happening? The state does but won't say.

All six cases of E. coli in the recent Illinois outbreak were reported by the same northern Illinois county, a state spokeswoman said Wednesday. But state and federal officials would not say which county.

A Cook County Department of Public Health spokesman said the cases were not in its jurisdiction, one that excludes Chicago, Evanston, Skokie, Oak Park and Stickney Township. The Chicago Department of Public Health could not be reached for comment.

Melaney Arnold, a spokeswoman for the Illinois Department of Health, said the six were contaminated with E. coli O157:H7 between late August and mid-September.

They were hospitalized after eating iceberg lettuce distributed by Aunt Mid’s Produce Company, prompting a statewide warning by the state’s Department of Public Health. At least 26 people in Michigan have also fallen ill after consuming Aunt Mid’s lettuce.

Illinois officials have not explicitly stated that the lettuce was contaminated or caused the illness.

“Right now what we’re able to say is that basically six people who consumed this iceberg lettuce that was distributed by Aunt Mid’s reported having E. coli that is the same strain as other cases that are in Michigan,” Arnold said.

Aunt Mid’s has voluntarily suspended the sale and processing of iceberg lettuce while the investigation is underway. The Illinois Department of Public Health has asked all restaurants and institutions to discontinue serving iceberg lettuce they may have purchased from Aunt Mid’s.

E. coli O157 is found in the intestines of animals such as cattle, goats and sheep, according to the Centers for Disease Control and Prevention.

“Often what happens is that contamination from animal feces sometimes makes its way to contaminate other foods,” said Dr. Mark Sotir, epidemiologist in the CDC’s Department of Foodborne, Bacterial and Mycotic Diseases, Wednesday.

People contaminated by E. coli O157 often have cramps, diarrhea and vomiting, according to the CDC.

“Although the majority of people recover, it can be a very serious disease with the possibility of death,” Sotir said.

Dr. Sotir and his colleague Dr. Samir Sodha, also an epidemiologist at the CDC, said hemolytic uremic syndrome (HUS) affects 8 percent of people diagnosed with E. coli O157, and is one of its most severe complications. Those with HUS suffer kidney failure, and in some cases, stroke, seizure and even death.

“A couple of populations that are specifically vulnerable to getting HUS are the elderly and young children,” Sotir said. “That’s why in the public health community, we’re particularly concerned with investigating these outbreaks of E. coli O157.”

Dominic Riggio, president of Aunt Mid’s, said the company has been fully cooperating with Michigan health officials by giving them samples, agreeing to numerous physical inspections of the facility, and sharing lab tests and lab results.

“We have nothing to hide,” Riggio said.

Riggio said he feels that allegations against his company are unsupported.

“There have been no hard facts and no evidence that any of Aunt Mid’s products have been contaminated with E. coli,” Riggio said Wednesday. He added that he has not been informed of the outcome of Michigan’s tests.

He would not comment on where the company's iceberg lettuce is grown.

Arnold said that Aunt Mid’s only performs large-scale distribution, so the public should not be concerned about iceberg lettuce sold in grocery stores. She advised people to take precautionary measures when preparing food.

“It is very important that you thoroughly wash all produce, no matter what type it is, and even in packages that say "pre-washed," she said.

Last year, 137 cases of E. coli were reported in Illinois. Seventy-one cases, not including the six in the recent outbreak, have been reported in 2008.