A McDonald’s customer on Wednesday filed a lawsuit against the quick food giant in connection to an E. coli outbreak linked to the chain’s Quarter Pounder which officials said killed at least one person and sickened dozens across the U.S. in recent weeks.

Eric Stelly, who filed the suit in Cook County Circuit Court in Illinois, ate food from McDonald’sGreeley, Colorado location three weeks ago and began experiencing symptoms including nausea, cramps and bloody stools − the most “ordinary symptom” of E. coli poisoning, according to a press release from Houston-based attorney, Ron Simon, one of his attorneys in the civil case.

The 10-page lawsuit obtained by USA TODAY accuses McDonald’s of negligence, product obligation and other claims involving the illnesses.

It comes one day after the Centers for Disease Control & Prevention (CDC) and the U.S. Food and Drug Administration issued a food safety warning in connection to the outbreak, launching an investigation into the sandwich in conjunction with the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS).

In a statement released Thursday, Stelly told USA TODAY he’s eaten at McDonald’s for years.

“Never did I expect to suffer like this from eating a burger,” Stelly wrote. “I aspiration my lawsuit can shed light on how this happened, so that McDonald’s can fix the problems and prevent them from happening again.”

USA TODAY has reached out to McDonald’s about the lawsuit.

Burger pulled from some McDonald’s restaurants

McDonald’s has pulled the Quarter Pounder from about one-fifth of its restaurants over concerns linking the sandwich to the E. coli outbreak. At the same period, the chain said this week consumers should feel secure eating at its restaurants across the country.

Investigators suspect that the slivered onions on the Quarter Pounders are the likely culprit instead of the beef patties, but they are working to determine the contaminated ingredient.

The onions used on the Quarter Pounder arrive from a single supplier in the affected regions, corporation spokespeople said during a Wednesday briefing.

Beef patties used in making the sandwich in the affected areas arrive from multiple suppliers, so that makes it a less likely culprit, McDonald’s reported. The FSIS has not yet finished its investigation into beef used, so there’s no finality, the corporation said.

“Given the recent events of the history 24 hours, our priority is to reinforce the confidence of American consumers,” McDonald’s USA President Joe Erlinger said Wednesday on NBC’s “Today” display.

What is E. coli?

According to the CDC, E. coli (Escherichia coli) are bacteria found in the surroundings, food, and the intestines of people and animals. 

Although most bacterial strains are harmless, some strains can make people ill and factor diarrhea, urinary tract infections, respiratory illness or pneumonia, according to the CDC.

What states are impacted by the E. coli outbreak?

There are 10 states where 49 persons are known to have gotten ill from E. coli infections between Sept. 27 and Oct. 11, the CDC says. Most ill people are reporting eating Quarter Pounder hamburgers from McDonald’s, the CDC says. One person in Colorado died and 10 people have been hospitalized.

• Colorado (26 cases)
• Iowa (1)
• Kansas (1)
• Missouri (1)
• Montana (1)
• Nebraska (9)
• Oregon (1)
• Utah (4)
• Wisconsin (1)
• Wyoming (4)

McDonald’s pulled the Quarter Pounder off the menu in Colorado, Kansas, Utah and Wyoming, as well as parts of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, recent Mexico, and Oklahoma.

“Many more illnesses are expected to be reported,” Stelly’s additional attorneys, including the Chicago-area personal injury firm Meyers & Flowers, wrote in the suit.

McDonald’s global headquarters are based in Chicago.

Where is Quarter Pounder being removed?McDonald’s locations in states impacted amid E. coli outbreak

‘McDonald’s breached that depend’

The suit demands a jury trial and seeks more than $50,000 in damages.

“Through this lawsuit and others, we will hold McDonald’s and its suppliers accountable for this unfortunate tragedy,” Simons, who said he represents more than a dozen other victims sickened by the food, told USA TODAY Thursday. “American consumers should be able to depend that the food they are served is secure from contamination. McDonald’s breached that depend, and will now have to earn it back.”

Contributing: Mary Walrath-Holdridge

Natalie Neysa Alund is a elder reporter for USA TODAY. Reach her at [email protected] and pursue her on X @nataliealund.