What we know about the McDonald's E. coli outbreak

McDonald’s has temporarily removed quarter pounders and fresh onions from menus in about 20% of U.S. stores due to a deadly E. coli outbreak, with 49 reported cases and one death.

The CDC suspects onions as the contamination source, possibly linked to supplier Taylor Farms, though testing hasn't confirmed this. Other chains like Burger King and Yum! Brands are also discarding onions as a precaution.

McDonald’s stock initially dropped after the news, and the company faces its first lawsuit from an affected customer. They aim to reintroduce quarter pounders in impacted states soon.