Portugal Colonial - McDonald's linked to dozens of food poisonings, one death in US

The outbreak, which began in late September, has spread across 10 western states with most of the 49 cases concentrated in Colorado and Nebraska, the health agency said.

Shares in the fast food chain dropped more than eight percent in after hours trading following the announcement.

Ten people have been hospitalized, including one child with hemolytic uremic syndrome -- a serious condition that damages blood vessels in the kidneys.

"One older person in Colorado has died," the CDC statement said.

All affected people carried the same strain of E. coli and reported eating McDonald's Quarter Pounders before developing their symptoms.

While investigators have not yet pinpointed the exact ingredient causing the outbreak, they are focusing on slivered onions and beef patties -- both of which have been removed from restaurants in the affected states pending further investigation.

Quarter Pounder hamburgers in some states may be temporarily unavailable, added the CDC.

The agency advised those who consumed a Quarter Pounder and developed symptoms of E. coli poisoning -- such as diarrhea, a fever over 102 degrees Fahrenheit (38.9°C), and vomiting -- to seek medical attention.

Symptoms typically begin three to four days after exposure, and most individuals recover within five to seven days without treatment. However, some cases can become severe and require hospitalization.

McDonald's did not immediately respond to a request for comment.

O.Gaspar--PC