E. coli Outbreak Linked to McDonald's Quarter Pounder

By Lisa Baertlein and Sneha S K

(Reuters) – One person has died and dozens were sickened from E. coli infections linked to McDonald's (NYSE:MCD) Quarter Pounder hamburgers in 10 states, the U.S. Centers for Disease Control (CDC) said on Tuesday.

Shares of the company fell about 6% in extended trading following the CDC's announcement that 49 people were affected by the E. coli O157:H7 strain, which can cause serious illness. This strain is notably associated with a deadly 1993 outbreak that killed four children after they consumed undercooked hamburgers at Jack in the Box (NASDAQ:JACK).

Everyone interviewed reported eating at McDonald's before falling ill, with many specifically mentioning the Quarter Pounder. While the specific ingredient causing the illness hasn't been confirmed, investigators are focusing on fresh, slivered onions and fresh beef patties.

Most reported illnesses were in Colorado and Nebraska.

Cesar Piña, McDonald's North America Chief Supply Chain Officer, stated that initial investigation findings suggest a subset of illnesses may relate to slivered onions sourced from one supplier serving three distribution centers. McDonald's has proactively removed the affected slivered onions and beef patties from stores in the impacted states as the investigation continues.

Top U.S. food safety attorney Bill Marler, who has represented victims in past outbreaks, suggested that onions are the likely source of contamination and have been previously linked to E. coli O157:H7 outbreaks. Marler mentioned that beef seems unlikely to be the cause due to improved food safety measures, stating, “You'd have to have multiple restaurants under cooking the meat.” He anticipates more cases will emerge from this outbreak.

McDonald's is temporarily removing the Quarter Pounder from restaurants in the affected areas, including Colorado, Kansas, Utah, and Wyoming, while working with suppliers to replenish stock in the coming week.

Symptoms of E. coli infection include severe stomach cramps, diarrhea, and vomiting. In 2015, burrito chain Chipotle (NYSE:CMG) suffered sales declines and reputation damage due to E. coli outbreaks linked to the E. coli O26 strain, which typically leads to less severe illness than E. coli O157:H7.