At least 49 people have fallen ill in 10 US states due to contaminated food, according to health authorities.

US fast-food chains including Burger King, KFC and Taco Bell have pulled fresh onions from some restaurants after an E coli outbreak linked to McDonald’s Quarter Pounder sandwiches sickened dozens of people.

Burger King’s parent company, Restaurant Brands International, and Yum Brands, which operates Taco Bell, Pizza Hut and KFC, made the announcement on Thursday as McDonald’s named a California-based supplier as the source of onions linked to the food poisonings.

Illegal Pete’s, a Mexican fast-food chain based in Colorado, also announced that it had temporarily pulled several menu items that include onions.

Taylor Farms, based in Salinas, California, did not immediately respond to a request for comment.

McDonald’s pulled its Quarter Pounder from about one in five outlets in the US after the Centers for Disease Control and Prevention (CDC) earlier this week linked the item to cases of food poisoning in 10 states.

At least 49 people have fallen ill, mostly in Colorado and Nebraska, including one older adult who died, according to health authorities.

Authorities have identified the bacteria behind the illnesses as E coli O157:H7, which causes more than 2,000 hospitalisations and 61 deaths in the US each year, according to the CDC.

Symptoms of E coli poisoning can occur within a day or two of eating contaminated food and typically include fever, vomiting, diarrhoea and signs of dehydration.

E coli is particularly dangerous for young children and those who are elderly, pregnant or who have compromised immune systems.