How disease detectives' quick work traced deadly E. coli outbreak to McDonald's Quarter Pounders

A recent outbreak of E. coli linked to McDonald's has affected individuals across 13 states in the US. A teenage boy from Grand Junction, Colorado, became severely ill after consuming a Quarter Pounder from McDonald's, highlighting the seriousness of the outbreak. He experienced intense stomach cramps and bloody diarrhea, prompting a visit to the emergency room where tests confirmed an E. coli infection. 

Local and state health departments launched investigations, quickly connecting multiple cases to the fast-food chain. Experts identified slivered onions from a specific supplier as the likely source of contamination. McDonald's responded by halting sales of certain menu items and discontinuing sourcing onions from the identified facility. 

As the investigation continues, officials warn that the number of cases may rise as more tests are processed. The company reiterated its commitment to food safety, while victims seek legal action and continue to recover from their illnesses.