McDonald's E. coli outbreak: See latest map of cases as Quarter Pounder returns to menus

The Quarter Pounder is back on the menu this week at all McDonald's locations following an E. coli outbreak linked to onions used in its burgers, though the company warns "case counts will grow."

The move comes after the Colorado Department of Agriculture finished testing samples taken from Quarter Pounder beef patties, finding "no detection of E. coli,” McDonald's North America Chief Supply Chain Officer Cesar Piña said.

"The issue appears to be contained to a particular ingredient and geography, and we remain very confident that any contaminated product related to this outbreak has been removed from our supply chain and is out of all McDonald’s restaurants," the company said in a statement.

But "health officials have noted that with increased awareness, more people will seek medical attention and case counts will grow," the company continued. "This awareness is a good thing, as it can lead to people being vigilant and connecting with medical professionals."

The U.S. Centers for Disease Control and Prevention said there have been at least 75 people sickened across 13 states, with 22 out of the 75 people requiring hospitalization and one reported death. The Colorado Department of Public Health identified that the one death occurred in the state and was an "older person with underlying conditions."

Government officials are working to identify the source of the outbreak.

E. coli outbreak map

States with reported E. coli illnesses as of Oct. 28

The CDC reported that illnesses had occurred in the following states:

• Colorado
• Iowa
• Kansas
• Michigan
• New Mexico
• Washington
• Montana
• Missouri
• Nebraska
• Oregon
• Utah
• Wisconsin
• Wyoming

What is E. coli? What are the symptoms?

Most Escherichia coli (E. coli) bacteria reside harmlessly in the intestines of people and animals. But some can cause mild to life-threatening gastrointestinal illnesses if consumed, the CDC says.

The types of E. coli that may cause diarrhea usually spread through food or water contaminated with feces. For instance, food handlers can spread infection when they do not use proper hand washing hygiene after using the restroom. Animals such as cattle may also spread E. coli to food and food crops.

Symptoms of E. coli infection include severe stomach cramps, diarrhea (often bloody), and vomiting, according to the CDC.

The agency recommended seeking immediate medical attention if a McDonald's customer experiences:

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

Fernando Cervantes Jr. is a trending news reporter for Paste BN. Reach him at fernando.cervantes@gannett.com and follow him on X @fern_cerv_.