By TELEMUNDO CHICAGO / NBC CHICAGO • Published on October 22, 2024

McDonald’s has removed some ingredients from its menu in various locations as dozens of people have fallen ill with E. coli across multiple states, all after eating the popular Quarter Pounder hamburgers.

The outbreak has been reported in at least 10 U.S. states so far, with most cases reported in Colorado and Nebraska, though several Midwestern states have also reported cases.

In total, 49 people have fallen ill, 10 of whom were hospitalized, and one person has died.

"All of those interviewed reported eating at McDonald’s before their illness began, and more specifically mentioned eating a Quarter Pounder hamburger," the Centers for Disease Control and Prevention (CDC) said in a Tuesday alert, calling it a "rapid outbreak investigation."

Investigators have been working to find the source of the outbreak, focusing on two ingredients so far: fresh onions and beef patties.

"McDonald’s has pulled the ingredients for these hamburgers, and they will not be available for sale in some states," the CDC reported.

The CDC stated that McDonald’s "is making these changes proactively as investigators work to confirm the contaminated ingredient," and noted that the Quarter Pounder beef patties are only used at the fast-food chain headquartered in Chicago.

NBC Chicago and Telemundo Chicago reached out to McDonald’s for comment on the outbreak and were provided with an internal message shared within the company by Cesar Piña, SVP, Head of Supply Chain, North America, and Joe Erlinger, President of McDonald’s USA.

Of the cases reported to date, 27 have been reported in Colorado, including the death, and nine have been reported in Nebraska. Other states reporting cases include Iowa, Kansas, Missouri, Montana, Oregon, Utah, Wisconsin, and Wyoming.

"McDonald’s is making these changes proactively as investigators work to confirm the contaminated ingredient. The Quarter Pounder beef patties are only used for Quarter Pounders," the CDC stated.

What You Should Do
The CDC urged anyone experiencing E. coli symptoms after eating at McDonald’s to contact their healthcare provider.

According to the CDC, most people infected with E. coli experience severe stomach cramps, diarrhea, and vomiting. Symptoms typically appear within three to four days after ingesting the bacteria, and most people recover within five to seven days.

Symptoms include:

• Diarrhea and a fever higher than 102°F
• Diarrhea for more than 3 days that isn’t improving
• Bloody diarrhea
• So much vomiting that you can’t keep liquids down
• Signs of dehydration, such as:
  • Not urinating much
  • Dry mouth and throat
  • Feeling dizzy when standing up

Some people may also develop serious kidney problems known as hemolytic uremic syndrome (HUS), which requires hospitalization. The CDC noted that at least one child experienced this symptom in connection with this outbreak.