McDonald’s E. Coli outbreak hits at least 10 states in CDC ‘fast-moving’ investigation: Symptoms, update, and what you need to know

An outbreak of E. coli has been linked to McDonald’s restaurants in the US heartland, prompting the fast food chain to temporarily remove the old food from its menu. The company has pulled the famous Quarter Pounder from restaurants in Colorado, Kansas, Utah, and Wyoming, as well as parts of eight other states.

McDonald’s is cooperating with the investigation, which was reported today by the US Centers for Disease Control and Prevention (CDC). So far, the outbreak has resulted in at least one death, 10 hospitalizations, and 49 infections in 10 states, according to the CDC. Here’s what you need to know:

What is the origin of the outbreak?

Early indications in the investigation suggest that the outbreak may be linked to leftover onions used in Quarter Pounder hamburgers from a single, unnamed supplier serving three distribution centers.

Fast company has reached out to McDonald’s for comment, but has yet to hear back. The company has publicly shared an internal message about how it is taking “immediate and decisive action” to address the outbreak, including working with the CDC to provide updates to the public.

The Des Plaines, Illinois-based chain noted that the Quarter Pounder has also been removed from menus in parts of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico, and Oklahoma.

What if I ate at McDonald’s recently?

The CDC advises people who have eaten a McDonald’s Quarter Pounder hamburger to contact their health care provider if they have symptoms of E. coli, which can include:

• Diarrhea and fever above 102 degrees Fahrenheit
• The diarrhea is so bad that you can’t keep fluids down
• Symptoms of dehydration

The CDC indicated that many people infected with E. coli that produce Shiga toxin begin to show symptoms three to four days after ingesting the bacteria.

What else is McDonald’s doing to deal with this?

In a video message posted on YouTube this afternoon, Joe Erlinger, president of McDonald’s USA, emphasized that the outbreak does not affect menu items beyond the Quarter Pounder—and is limited to only a select number of US states.

The decision to remove the salvaged onions was made “progressively,” he said. “I hope these measures demonstrate McDonald’s commitment to food safety.”

How did McDonald’s stock react to this news?

Shares of McDonald’s (NYSE: MCD ) fell as much as 9.6% in after-hours trading, after closing typically lower for the day.

It’s been a busy week for the series; former president Donald Trump had a viral publicity stunt serving french fries at a McDonald’s restaurant in Pennsylvania.