Suspicion confirmed

Deadly bacteria: McDonald’s finds cause

The US version of the Hamburger Royal became a superspreader - one person even died from the E. coli infection.(Bild: APA/AFP/Getty ImagesScott Olson)

The excitement was great: after outbreaks of E. coli bacteria occurred in several McDonald's branches in the USA - dozens of cases were reported, one person even died - the company has now found the cause. Initial suspicions have been confirmed. 

The US health authority CDC has now named the "probable cause of illness for this outbreak", stating that sliced onions were to blame for the food scandal. This confirms the company's suspicions, which had already taken the precaution of offering burgers without the ingredient.

Company has already withdrawn onions from circulation
According to the CDC, a total of 90 illnesses were registered in 13 states - all of which can be traced back to the consumption of Quarter Pounders between September 27 and October 16.

At least 27 people had to be treated in hospital as a result, and one elderly person did not survive the infection. According to the authorities, no further cases were reported after the switch to onion-free burgers.

In initial investigations, the CDC still suspected the leek vegetables, but did not rule out the possibility that the meat itself could be affected. The onions now responsible are all likely to have come from a production facility in Colorado. However, the company now no longer wants to be supplied from there; a logistical effort, as around 900 of the chain's restaurants were previously supplied with sliced vegetables from there.

CDC: "Very low risk to the public"
"Based on the product measures taken by McDonald's and Taylor Farms (the company in Colorado, note), the CDC believes that the risk to the public remains very low," the CDC said in its statement. However, the specific onion farmer has not yet been identified.

According to the CDC, typical symptoms of severe illness include severe stomach cramps, bloody diarrhea and vomiting. According to the German Federal Institute for Risk Assessment, certain strains of E. coli bacteria can cause serious illnesses such as kidney failure.