Onions on McDonald's burgers may have caused E Coli outbreak: US public health body

E Coli outbreak linked to McDonald's Quarter Pounder hamburgers was first reported on October 22 and slivered onions were suspected to be the source of the infections.

In Short

• E Coli outbreak has sickened 90 people so far and killed one
• E Coli strain poses serious risk, affects 13 states
• McDonald's to resume Quarter Pounder burger sales this week

The US Centers for Disease Control and Prevention said on Wednesday that slivered onions served on McDonald's Quarter Pounder hamburgers and other menu items were the likely source of an E. coli outbreak that sickened 90 people.

The outbreak linked to Quarter Pounder was first reported on October 22, and slivered onions were suspected to be the source of the infections.

The US Food and Drug Administration and the company have confirmed that Taylor Farms was the supplier for the affected locations, and it has since recalled several batches of yellow onions produced in a Colorado facility.

The FDA on Wednesday said it had initiated inspections at a Taylor Farms processing centre in Colorado, a state where 29 people have fallen ill due to the outbreak.

An onion grower of interest in Washington state is also being investigated, the FDA added.

The CDC said the number of infected people has risen by 15 people from 75 and 27 persons have been hospitalised due to the illness, which has already killed one person.

On Sunday (October 27), the company along with the Colorado Department of Agriculture also ruled out the possibility of beef patties being a source of the outbreak.

The E. coli O157:H7 strain that led to the McDonald's outbreak is said to cause "very serious disease", especially for the elderly, children and people who are immunocompromised.

The FDA noted that symptoms begin anywhere from a few days after consuming contaminated food or up to nine days later.

As of October 30, the outbreak affected Colorado, Kansas, Utah, Wyoming, Iowa, Missouri, Montana, Nebraska, New Mexico, Oregon, Wisconsin, Washington and Michigan.

"To say the least, the more these cases arise in the news the harder it will be for McDonald's to reset," said Jim Sanderson, analyst with Northcoast Research.

McDonald's said that it would resume selling Quarter Pounders burgers this week after it temporarily took the item off the menu in a fifth of its 14,000 US restaurants that were impacted.

On Tuesday, company executives brushed off any potential sales hit from the outbreak, with CEO Chris Kempczinski apologising to customers and adding that he was "confident in the safety of eating at McDonald's".