US health authorities have said that fresh, slivered onions used by McDonald's were the cause of an E.coli outbreak that killed one and hospitalised 27 people.
The Centre for Disease Control and Prevention (CDC) said the onions were supplied by California-based company Taylor Farms, which issued a voluntary recall.
Earlier this month, the CDC issued a food safety alert when customers fell ill after eating the fast food chain’s quarter pounder hamburgers.
Restaurants in a dozen US states temporarily pulled the burgers from their menus following the outbreak.
One man in Colorado died from the disease, while 27 were hospitalised.
Around 90 people have fallen ill in total, according to the CDC.
In a statement, McDonald’s said the “900 restaurants that historically received slivered onions from Taylor Farms’ Colorado Springs facility” would resume selling the quarter pounders without slivered onions.
Taco Bell, Pizza Hut and KFC have removed onions from their products as a precaution.
McDonald’s stores in the UK and Ireland have not been affected.
The E.coli bacterium causes dangerous diarrhea and can lead to kidney failure and other serious problems.
People can contract disease when they consume contaminated foods or through contact with animals, the environment, or other people who are infected.
Symptoms tend to develop within a day or two of eating contaminated food and include fever and vomiting.
Last June, one person died after an E.coli outbreak in the UK spread via lettuce leaves.
The outbreak forced several food manufacturers to recall sandwiches, wraps and salads sold in major supermarkets including Tesco and Asda.
