On October 30, 2024, the Centers for Disease Control and Prevention (CDC) reported that fresh-cut onions may be the source of this E. coli outbreak, based on epidemiologic and traceback information.

A total of 90 cases of E. coli infections associated with this outbreak have been reported in 13 states in the U.S., and the number of hospitalizations has increased to 27, according to the CDC. According to CDC officials, onion chips used in a McDonald's burger called the “Quarter Pounder” are the likely direct source of the infection. The onion slices in question were supplied by the produce company Taylor Farms and were produced at a plant in Colorado.