The US Food and Drug Administration (FDA) announced an E.coli outbreak linked to McDonald’s Quarter Pounder hamburgers, affecting 75 people across the West and Midwest. The Centers for Disease Control and Prevention (CDC) reported on October 22 that one person has died, 49 are ill, and 10 have been hospitalized. The FDA later confirmed that 22 of the 61 cases with complete data have required hospitalization, with two patients developing hemolytic uremic syndrome—a rare, potentially fatal kidney complication.

McDonald’s has since removed the Quarter Pounder from its menu at locations in Colorado, Kansas, Utah, Wyoming, and parts of eight other states, affecting about 20% of its 14,000 US restaurants. The company’s shares dropped by 2% following the news, as investigations continue to contain the outbreak and assess further risks to public health.

Earlier today (October 25), leading US fast-food chains have temporarily removed fresh onions from their menus, after the vegetable was identified as the probable source of an E. coli outbreak linked to McDonald’s. This incident underscores a longstanding challenge for the restaurant industry—ensuring contamination-free produce.

The US Department of Agriculture reported that onions are the likely cause of this outbreak, which has impacted several states across the Midwest and the West.

(With inputs from Reuters)