US fast-food chains pull onions from menus after McDonald’s E coli outbreak Al Jazeera EnglishOnions Recalled in Deadly E.Coli Outbreaks Linked to McDonald’s Quarter Pounders The New York TimesE. coli Outbreak Linked to McDonald’s Quarter Pounders CDCFirst lawsuit filed against McDonald’s over its E. coli outbreak CNNNebraska woman suing McDonald’s says E. coli landed her in the ER NBC News