E Coli outbreak in US: One dead, dozens fall sick after deadly E coli outbreak linked to McDonald's

E Coli outbreak in US: A major E. coli outbreak linked to McDonald's Quarter Pounder hamburgers has killed one person and sickened several, according to the US Centres for Disease Control and Prevention (CDC) on Tuesday.

The outbreak began in late September and has spread to ten western states, with the majority of the 49 cases concentrated in Colorado and Nebraska, according to the health service.

The fast food chain's shares fell more than 6% in after-hours trading on the announcement.

Ten people have been hospitalised, with one child suffering from hemolytic uremic syndrome, a dangerous illness that affects blood vessels in the kidneys.

"One older person in Colorado has died," according to a CDC release.

All affected persons had the same strain of E. coli and reported eating at McDonald's before experiencing symptoms, with the majority recalling having Quarter Pounders.

While investigators have yet to identify the particular product that is causing the outbreak, they are focussing on slivered onions and beef patties, both of which have been withdrawn from restaurants in the affected states pending further research.

"Food safety is so important to me and everyone at McDonald's. We've taken steps to proactively remove slivered onions, which are used in Quarter Pounders, in select states. We've also made the decision to temporarily remove the Quarter Pounder from restaurants in select states," said Joe Erlinger, president of McDonald's USA in a video message.