- McDonald's shared more insights Wednesday into its investigation into a deadly E. coli outbreak.
- Executives said its investigation suggested the outbreak differed from what Chipotle faced in 2015.
- McDonald's said early indicators suggest slivered onions as a likely potential containment, but it couldn't rule out fresh beef.
McDonald's shared more insights Wednesday into the ongoing investigation into a deadly E. coli outbreak across 10 US states that the CDC says has sickened 49 people and led to one death.
On a media briefing call, McDonald's executives reiterated that its Quarter Pounder was the only menu item linked to the outbreak.
Two ingredients — the slivered onions and fresh beef patties — are being examined as potential sources of contamination. The company said that all potentially affected food products have been recalled from its impacted stores.
McDonald's executives said initial indicators point to the slivered onions as the more likely source, though they're not ruling out the fresh beef patties.
The company also said that while slivered onions are used on a breakfast sandwich in some markets, that menu item isn't impacted as it was not available in the affected locations.
When asked how this case compares to prior E. coli outbreaks linked to Chipotle, the McDonald's representatives said the two appear to be different.
The Chipotle cases involved the handling and preparation of food in restaurants, McDonald's executives said. This outbreak involves potentially contaminated ingredients arriving from a supplier. The McDonald's cases also represent a relatively low percentage of its overall food served and in an isolated geographic area, and contamination hasn't affected other menu items, they added.
Chipotle agreed to pay a $25 million fine in 2020 to resolve criminal charges related to foodborne illnesses that caused over 1,100 people to get sick between 2015 and 2018.
In an interview with NBC earlier in the day, McDonald's USA president Joe Erlinger said the company is working closely with federal agencies to identify and contain the issue.
"If there has been contaminated product within our supply chain, it's very likely worked itself through," he said. "Certainly we'll be working with the CDC and cooperating with them on the investigation."
While E. coli contaminations can be associated with raw or undercooked meat, the company said in the briefing that the beef used in its Quarter Pounder hamburgers is sourced from multiple different suppliers in the affected region.
In addition, the officials said that multiple restaurants would have had to fail to prepare the meals according to the company's standards, which specify burgers must be cooked to an internal temperature of 175 degrees Fahrenheit — 15 degrees higher than the threshold where E. coli is killed.
The company also said it performs periodic quality control checks throughout each day of operation and that the cases identified by the CDC spanned a nearly two-week period. During that time, roughly a million quarter pounders are usually sold in that region.
McDonald's said the slivered onions sold at affected restaurants come from a single supplier and are served raw on the sandwich.
The company said it is unclear where in the supply chain contamination might have occurred if it did, as onions are farmed, washed, and sliced before being further disinfected, bagged, and sent to restaurants in refrigerated shipments. Executives said this strain of E. coli had never before been traced to onions.
The company also said the CDC and FDA first notified it of the outbreak late last week, but that confirmed case numbers were much lower than they were on Tuesday when the public notice was announced.
Until a definitive single source of the outbreak is identified, the company has halted sales of its Quarter Pounder menu items in the affected region, which impacts about one-fifth of its store fleet.
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