Quarter Pounder E. coli outbreak triggers a major food-safety crisis
On October 22, 2024, U.S. health authorities announced a severe E. coli outbreak linked to McDonald's Quarter Pounders, leading the company to remove affected ingredients and suspend sales in some markets while investigators examined the source. The outbreak was a major recent milestone because it showed how quickly food-safety problems can threaten trust in a global restaurant chain. Federal agencies later tied the outbreak to yellow onions supplied through the distribution chain, and by December 2024 the investigation was closed, but the episode underscored the operational and reputational risks of large-scale food systems.