The CDC reported that everyone affected had eaten at McDonald’s prior to their illness, with most recalling having a Quarter Pounder. Investigators are focusing on slivered onions and fresh beef patties as potential sources, though the exact ingredient has not yet been identified.
McDonald’s has removed the slivered onions and beef patties from stores in the affected states, including Colorado and Nebraska, as a precaution. U.S. food safety attorney Bill Marler noted that onions have been tied to past E. coli outbreaks, while beef contamination is rarer due to strict food safety measures.
The outbreak has impacted McDonald’s stock, which fell 6% in after-hours trading, and could further affect U.S. cattle futures by weakening beef demand. The fast-food chain has temporarily pulled the Quarter Pounder from restaurants in Colorado, Kansas, Utah, and Wyoming while it works to restock safe supplies.
What is E. Coli?
E. coli (Escherichia coli) is a type of bacteria commonly found in the intestines of humans and animals. While most strains are harmless, some, like E. coli O157, can cause severe illness. This particular strain produces toxins that lead to stomach cramps, diarrhea, and vomiting. Infections often result from consuming contaminated food or water, and symptoms typically appear three to four days after exposure, though they can start anywhere from one to 10 days later.
Experts have warned that additional cases of current E. coli O157 outbreak may emerge as the investigation continues.