An E. coli outbreak linked to McDonald’s Quarter Pounder burgers in the United States has sickened at least 49 people and caused one death. Cases have been reported in 10 states so far, with the majority of illnesses in Colorado and Nebraska.

On Tuesday, the U.S. Centers for Disease Control and Prevention issued a food safety alert announcing that it is investigating an outbreak of E. coli O157:H7 infections in several states linked to contaminated McDonald’s Quarter Pounders.

The CDC called the outbreak “severe” in a news release, adding that McDonald’s had temporarily removed the suspected ingredients.

Escherichia coli (E. coli) are bacteria that occur in the intestines of humans and animals. Some species, such as E. coli O157:H7, can produce powerful toxins that can cause serious and potentially fatal illness. Symptoms include bloody diarrhea, severe stomach cramps and vomiting.

McDonald’s E. coli outbreak 2024

At least 49 cases of E. coli have been reported in 10 states so far in this outbreak, but “the actual number of people sickened is likely much higher,” the CDC said.

All people interviewed as part of the research said they had eaten a McDonald’s hamburger before symptoms appeared, with Quarter Pounders being the most frequently mentioned.

In a statement released Oct. 22, McDonald’s said it would “take swift and decisive action.”

According to the CDC, Quarter Pounders are temporarily unavailable for purchase at McDonald’s stores in 11 states and investigators are working to determine which specific ingredient(s) are contaminated with E. coli.

According to the CDC, two ingredients used in Quarter Pounders are currently being investigated: fresh onion slices and quarter-pound beef patties.

On TODAY on Oct. 23, Joe Erlinger, president of McDonald’s USA, discussed the outbreak, saying consumers can “confidently go to McDonald’s today” and eat the classics without getting sick.

“Food safety is our top priority at McDonald’s,” Erlinger said.

One person died and ten were hospitalized

One older adult has died in Colorado due to the outbreak. At least 10 people were hospitalized, including a child who developed hemolytic uremic syndrome (HUS), a serious condition that can lead to kidney failure, the CDC said.

The sick people are between 13 and 88 years old.

The illnesses associated with this outbreak began between September 27, 2024 and October 11, 2024. It is also possible that there are newer illnesses that have not yet been reported, as it can take three to four weeks for the illness to become one One person is linked to an outbreak, according to the CDC.

E. coli outbreak states affected by McDonald’s

The outbreak has affected 10 states so far, with Colorado reporting the most cases, followed by Nebraska and Wisconsin, according to the latest CDC data.

Affected States and Number of Diseases Reported:

• Colorado: 26
• Nebraska: 9
• Wisconsin: 4
• Iowa: 1
• Kansas: 1
• Missouri: 1
• Montana 1
• Oregon: 1
• Utah: 1
• Wyoming: 1

“This outbreak may not be limited to states with known illnesses, and the actual number of people sickened is likely much higher than the reported number,” the CDC said on its website.

If you have questions about specific cases in your state, contact your state’s department of health, the CDC said in a news release.

States where McDonald’s has removed Quarter Pounders from the menu

While the investigation into the outbreak continues, McDonald’s locations in several states have temporarily stopped selling Quarter Pounder beef patties and fresh onion slices.

The quarter-pound patties are used only for Quarter Pounders, and the onion slices are “used primarily for Quarter Pounders and not for other menu items,” the CDC said.

McDonald’s locations in the following states (or parts of states) have temporarily removed Quarter Pounders from their menus:

• Colorado
• Kansas
• Utah
• Wyoming

Parts of:

• Idaho
• Iowa
• Missouri
• Montana
• Nebraska
• Nevada
• New Mexico

What is E. coli?

According to the CDC, E. coli is a type of bacteria found in the environment, food, water and digestive tracts of people and animals. While most types of E. coli are harmless or cause mild diarrhea, some types can cause serious illness.

Certain strains such as E. coli O157:H7 can produce powerful Shiga toxins that can cause life-threatening illnesses. The most common Shiga toxin-producing strain in the United States is E. coli O157:H7, which was implicated in the McDonald’s Quarter Pounder outbreak.

E. coli O157:H7 causes an estimated 73,000 illnesses per year in the United States

How do you get E. coli?

People can be exposed to E. coli by eating or drinking contaminated food or water. The main food sources for Shiga-producing E. coli outbreaks are raw or undercooked ground beef, raw vegetables, and raw milk or cheese.

According to the Cleveland Clinic, transmission can also occur by touching an infected person’s feces or contaminated surfaces. This can be due to poor hygiene after using the toilet, changing diapers and before eating.

According to the CDC, some people are more likely to become infected with E. coli. This includes children under 5, adults 65 and over, people with weak immune systems and international travelers.

Symptoms of E. coli infection

Symptoms of E. coli O157:H7 infection include:

• Stomach cramps, which can be serious
• Bloody or watery diarrhea
• Vomit
• Low fever

According to the CDC, symptoms usually appear three to four days after swallowing the bacteria from contaminated food.

Most people recover within a week, but some people may experience dehydration or life-threatening complications, including hemolytic uremic syndrome, which can lead to kidney failure.

The CDC urges anyone who has recently eaten a Quarter Pounder from McDonald’s and is experiencing severe symptoms to call their doctor.

If you notice signs of dehydration (decreased urine output, dry mouth, dizziness), severe vomiting, or a fever over 102 degrees Fahrenheit, seek medical attention immediately and tell the doctor what you have eaten.