The outbreak has been reported in at least 10 U.S. states so far, with most cases reported in Colorado and Nebraska, though several Midwest states have also reported cases
McDonald's released a statement Tuesday following an alert from the Centers for Disease Control and Prevention revealing a multistate E. coli outbreak linked to one of the chain's most popular menu items.
In a message to customers, the company said it was removing certain ingredients from its menus in some locations "out of an abundance of caution" as investigators work to determine the exact source of the outbreak.
In total, 49 people have been sickened so far across 10 U.S., including in Iowa, Missouri and Wisconsin. Ten people have been hospitalized and at least one death has been reported.
"Everyone interviewed has reported eating at McDonald's before their illness started, and most specifically mentioned eating a Quarter Pounder hamburger," the CDC said in an alert Tuesday, calling it a "fast-moving outbreak investigation."
Investigators have been working to find the source of the outbreak, centering in on two ingredients so far: fresh, slivered onions, and fresh beef patties.
"McDonald's has pulled ingredients for these burgers, and they won't be available for sale in some states," the CDC reported.
The CDC said McDonald's is "proactively making these changes while investigators work to confirm the contaminated ingredient" and noted that quarter pound beef patties are only used on the Chicago-based chain's Quarter Pounders.
Read their full statement below:
"Across the McDonald's System, serving customers safely in every single restaurant, each and every day, is our top priority and something we'll never compromise on.
It is why we are taking swift and decisive action following an E. Coli outbreak in certain states. The initial findings from the investigation indicate that a subset of illnesses may be linked to slivered onions used in the Quarter Pounder and sourced by a single supplier that serves three distribution centers. As a result, and in line with our safety protocols, all local restaurants have been instructed to remove this product from their supply and we have paused the distribution of all slivered onions in the impacted area.
Out of an abundance of caution, we are also temporarily removing the Quarter Pounder from restaurants in the impacted area, including Colorado, Kansas, Utah and Wyoming, as well as portions of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico, and Oklahoma. We take food safety extremely seriously and it's the right thing to do. Impacted restaurants are receiving a stock recovery notice today and should reach out to their field supply chain manager or distribution center with any questions.
We are working in close partnership with our suppliers to replenish supply for the Quarter Pounder in the coming weeks (timing will vary by local market). In the meantime, all other menu items, including other beef products (including the Cheeseburger, Hamburger, Big Mac, McDouble and the Double Cheeseburger) are unaffected and available. We will continue to work with the Centers for Disease Control and Prevention (CDC) and are committed to providing timely updates as we restore our full menu."
What to know about the outbreak:
The outbreak has been reported in at least 10 U.S. states so far, with most cases reported in Colorado and Nebraska, though several Midwest states have also reported cases.
Of the cases reported so far, 26 have been reported in Colorado, plus one death, and nine have been reported in Nebraska. Other states to report cases include Iowa, Kansas, Missouri, Montana, Oregon, Utah, Wisconsin and Wyoming.
The CDC warns, however, that the outbreak may not be limited to the states with illnesses discovered so far "and the true number of sick people is likely much higher than the number reported." This is because illnesses can take time to report and many people recover from E. coli without needing treatment.
Here's the full number of people sickened by state so far:
(Note: the death in Colorado is not included in the numbers below)
Of those sickened, ages range from 13 to 88 years, the CDC noted.
The exact source of the outbreak remains unclear, but investigators believe it is likely tied to either fresh, slivered onions or the fresh beef patties used in the Quarter Pounder.
McDonald's said in its statement the removal of ingredients was "out of an abundance of caution," but includes locations in Colorado, Kansas, Utah and Wyoming, as well as portions of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico, and Oklahoma.
"Preliminary traceback and distribution information reviewed by FDA shows that slivered onions served on Quarter Pounders are a likely source of contamination," the CDC stated. "FDA is working quickly to confirm that these onions are a source of this outbreak and to determine if these onions were served or sold at other businesses."
The CDC urged anyone who experiences E. coli symptoms after eating at McDonald's to call 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 of ingesting the bacteria, and most people recover between five and seven days.
Symptoms include:
Some people may also develop serious kidney problems known as hemolytic uremic syndrome, or HUS, which requires hospitalization. The CDC noted that at least one child experienced that symptom in connection with this outbreak.
According to the Mayo Clinic, E. coli stands for Escherichia coli, a bacteria that normally lives "in the intestines of healthy people and animals."
"Most types of E. coli are harmless or cause relatively brief diarrhea. But a few strains ... can cause severe stomach cramps, bloody diarrhea and vomiting," the clinic reported.
People can be exposed to the bacteria from contaminated water or food, particularly raw vegetables or undercooked ground beef.