E. Coli Outbreak Affects McDonald's Quarter Pounders – Here's What To Know

A coalition of federal, state, and local organizations announced on Tuesday, October 22, 2024, that it is investigating reports of E. coli O157:H7 infections across several states. In a preliminary statement issued by the FDA, the agency says that no one ingredient has been confirmed as the source of the outbreak, but most of those stricken reported eating some version of a McDonald's Quarter Pounder. The response coalition includes the FDA, along with the CDC, the USDA, and the Food Safety and Inspection Service (FSIS), according to a release shared with Chowhound.

McDonald's announced that it has temporarily stopped using the slivered onions and beef patties found in Quarter Pounders and that other food items on the menu, including diced onions and other patties, are not currently implicated. Quarter Pounders use fresh beef patties, whereas other burgers on the menu, like the classic hamburger, employ flash-frozen patties and fine-diced onions rather than sliced, slivered onions. This is an ongoing story, and the FDA reports that updates will be provided as they become available.

Based on reports of illnesses and traceback and distribution information, preliminary data suggests that the source of the contamination and outbreak could be the slivered onions used on Quarter Pounders, per the FDA. In addition, unlike most of McDonald's other sandwiches, the Quarter Pounder and its variations use fresh beef. The FSIS is conducting additional traceback analysis on the patties. Though only the Quarter Pounder with Cheese was named in the announcement, the same patties and onions are used on the Quarter Pounder with Cheese Bacon, Quarter Pounder Deluxe, and the Double Quarter Pounder with Cheese.

Illnesses have been reported in several states, and McDonald's in these locations have stopped serving the affected patties and onions, according to the FDA: Colorado, Kansas, Utah, Wyoming, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico, Oklahoma, and parts of Idaho. No other information was provided about the number of people reporting illnesses or their condition.

Escherichia coli include a variety of coliform bacteria, some of which are harmful to humans. The FDA shared some common symptoms, which can include diarrhea, severe stomach cramps, fever, nausea and vomiting. In some cases, infections can be life-threatening and lead to kidney failure and other complications. Symptoms begin appearing within a few days of consumption (via Mayo Clinic).

If you've eaten a Quarter Pounder in the past week in any of these states and feel you may be at risk of infection or are experiencing any of these symptoms, the FDA recommends that you contact your health care provider. Let the provider know what you ate, when, and from which McDonald's store if you know. If you still have a Quarter Pounder that you've purchased in the past few days, the best course of action is to safely discard it.