THURSDAY, Oct. 31, 2024 (HealthDay News) -- Onions spread on McDonald's Quarter Pounders are the definite source of an outbreak of E. coli illness that's now affected 90 people nationwide, new evidence from the U.

S. Centers for Disease Control and Prevention shows. "Epidemiologic and traceback information show that fresh, slivered onions are the likely source of illness in this outbreak," the CDC said in an update issued Wednesday.

The onions were traced to a Colorado producer, Taylor Farms. Since the agency's last update issued on Sunday, 15 more cases of E. coli illness linked to the onions in Quarter Pounders have been confirmed.

Five more people fell so ill that they required hospitalization, bringing that total to 27. One person in Colorado has died from the outbreak. The threat may be gone for anyone currently eating at McDonald's, the CDC noted.

"All new illnesses occurred before McDonald’s and Taylor Farms took action to remove onions from food service locations," the agency said. "Due to the product actions taken by McDonald’s and Taylor Farms, the CDC believes the continued risk to the public is very low." As announced by the company on Sunday, McDonald's Quarter Pounder beef patties did test negative for E.

coli contamination. "Over the weekend, McDonald’s was informed that the Colorado Department of Agriculture has completed their testing, the results of which confirm that there was no detection of E. coli in the samples taken of Quarter Pounder beef patties.