The following is from the CDC.

A CDC Food Safety Alert has been issued regarding an outbreak of E. coli infections linked to McDonald’s Quarter Pounder hamburgers. According to the CDC, 49 people across 10 states have been infected with the same strain of E. coli O157. Most cases have been reported in Colorado (27) and Nebraska (9). Ten people have been hospitalized, and one person has died from the infection.

Investigators are still working to identify the specific ingredient causing the outbreak. McDonald’s has proactively removed fresh slivered onions and quarter-pound beef patties from restaurants in the affected states as a precaution while the investigation continues. These ingredients are primarily used in Quarter Pounders and not in other menu items.

Key Points:

• 49 people from 10 states have been infected with E. coli O157. 
• Most cases are from Colorado (27) and Nebraska (9).
• 10 people have been hospitalized, and one older person in Colorado has died. Additionally, one child is hospitalized with hemolytic uremic syndrome (HUS).
• Everyone interviewed reported eating at McDonald’s before becoming ill, with most specifically mentioning Quarter Pounder hamburgers.
• Investigators are focusing on two potential ingredients: fresh slivered onions and quarter-pound beef patties.
• McDonald’s has temporarily removed the onions and patties from restaurants in the affected states while the investigation continues.

What You Should Do:

• If you ate a McDonald’s Quarter Pounder and experience severe symptoms of E. coli infection, seek healthcare immediately and inform your provider about what you ate.

Symptoms of E. coli:

• Severe stomach cramps, diarrhea (often bloody), and vomiting.
• Symptoms usually start 3 to 4 days after exposure to the bacteria.
• Most people recover without treatment in 5 to 7 days.
• Some may develop serious kidney problems (hemolytic uremic syndrome, or HUS) and need hospitalization.

Seek medical attention if you experience:

• Diarrhea with a fever higher than 102°F.
• Diarrhea for more than 3 days that doesn’t improve.
• Bloody diarrhea.
• Persistent vomiting that prevents you from keeping liquids down.
• Signs of dehydration, such as not urinating much, dry mouth, or feeling dizzy when standing.

For more information, read the full CDC’s Food Safety Alert here.