McDonald's E. coli food poisoning: Cases increase to 104 in outbreak tied to slivered onions

Around 104 people have become sick and 34 have been hospitalised amid an E. coli outbreak tied to slivered onions in McDonald's Quarter Pounder hamburgers, according to US health officials.

One person died in Colorado and four people have developed a potentially life-threatening kidney disease complication.

People in 14 US states have been affected, the Centers for Disease Control and Prevention (CDC) said.

Most of the people impacted were in the Mountain and midwestern states. Illnesses were reported between September 12 and October 21. At least seven people who got sick said they ate McDonald's food while travelling.

Slivered onions served on the Quarter Pounders were the likely source of the outbreak, according to the CDC. Taylor Farms, a California-based produce grower, recalled onions potentially linked to the outbreak.

Tests by the US Food and Drug Administration detected a type of E. coli bacteria that produces a dangerous toxin in one sample of the onions, but it did not match the strain that made people sick, officials reported.

Quarter Pounders were removed from menus in several states during the early days of the outbreak.

McDonald's officials said on Wednesday that the company identified an alternate supplier for the 900 restaurants that temporarily stopped serving the burgers with onions.

Over the past week, those restaurants resumed selling Quarter Pounders with slivered onions.

FDA officials said in a statement that “there does not appear to be a continued food safety concern related to this outbreak at McDonald's restaurants".

How many cases of E. coli food poisoning are there per year?

The type of bacteria implicated in this outbreak causes about 74,000 infections in the US annually, leading to more than 2,000 hospitalisations and 61 deaths each year, according to the CDC.

EU and EEA countries reported more than 8,500 cases of Shiga toxin-producing E. coli in 2022, according to the European Centre for Disease Prevention and Control (ECDC).

Symptoms occur quickly, within a day or two of eating contaminated food, and typically include fever, vomiting, diarrhoea or bloody diarrhoea and signs of dehydration, little or no urination, increased thirst and dizziness.

The infection can cause a type of serious kidney injury, especially in kids younger than 5. E. coli poisoning in young children requires immediate medical attention.