### McDonald's Halts Quarter Pounder Sales Amid E. Coli Outbreak Investigation

McDonald's has suspended the sale of its Quarter Pounder hamburgers at approximately one-fifth of its U.S. outlets following a significant E. coli outbreak that has resulted in nearly 50 illnesses and one fatality across 10 states. This precautionary measure comes as federal health officials endeavor to identify the source of the contamination.

A spokesperson for McDonald's revealed that around one million Quarter Pounders were sold during the period of the reported illnesses. The fast-food giant suspects that if the problem had originated from the patties themselves, more individuals would have fallen ill. The company speculates that the slivered onions, typically used in the Quarter Pounders, might be the vector for the bacteria.

The U.S. Centers for Disease Control and Prevention (CDC) recently connected the outbreak to the Quarter Pounders. Most of the affected individuals reported consuming these burgers, with cases primarily clustered in Colorado and Nebraska. Investigative efforts are ongoing to ascertain which specific ingredient is compromised. McDonald’s Chief Supply Chain Officer for North America, Cesar Piña, indicated that initial findings suggest the onions might be responsible.

Despite cooking their burgers at 175 degrees Fahrenheit—well above the 160-degree threshold needed to eradicate E. coli—McDonald's noted that the slivered onions, supplied by a single source, are served raw. This acknowledgment raises the possibility that these onions could indeed be the contamination source. The company has consequently removed the onions and beef patties from outlets in several states including Colorado, Kansas, Utah, and Wyoming, among others.

The CDC has reported a total of 49 E. coli cases linked to Quarter Pounders, with the largest numbers in Colorado (26 cases) and Nebraska (nine cases). Tragically, one elderly adult in Colorado succumbed to the illness. Additional cases have been logged in Utah, Wyoming, Iowa, Kansas, Missouri, Oregon, and Wisconsin.

At least 10 individuals have required hospitalization, with the onset of illnesses dating back to the end of September. The most recent case was reported on October 11. Among the hospitalized, one child is suffering from hemolytic uremic syndrome (HUS), a severe condition that can lead to kidney failure.

According to food safety expert Donald Schaffner of Rutgers University, the incubation period for E. coli is brief, typically only a few days. Therefore, those who consumed Quarter Pounders in September and have shown no symptoms are likely in the clear.

This incident recalls a previous 2018 outbreak, when more than 500 people fell ill due to salads from McDonald's. The current health scare has taken a toll on McDonald's stock, which dropped over 5% by Wednesday's trading close. This comes at a time when the chain is striving to appeal to consumers facing rising food costs, recently introducing a $5 value meal to attract lower-income customers.

As the investigation continues, McDonald’s urges anyone experiencing severe E. coli symptoms after eating a Quarter Pounder to seek medical advice immediately.