Number of people sickened by E. coli outbreak linked to McDonald's rises to 90: CDC

CHICAGO– The number of cases of the E. coli outbreak linked to McDonald’s Quarter Pounders has risen to 90, federal health officials said in a update on Wednesday.

According to the Centers for Disease Control and Prevention (CDC), cases have been reported in 13 states.

Most of the cases have occurred in Colorado, where 29 cases have been reported, and Montana, where 17 cases have been reported, according to the CDC.

Cases have also been reported in Iowa, Kansas, Michigan, Missouri, Nebraska, New Mexico, Oregon, Utah, Washington, Wisconsin and Wyoming, according to the CDC, which further notes that illnesses occurred between September 27 and October 16. this year.

At least 27 people have been hospitalized and two people developed hemolytic uremic syndrome (HUS), a serious condition that can cause kidney failure, the CDC said.

One death has been reported in Colorado in connection with the outbreak. The person was a resident of Mesa County in the western part of the state, according to police Mesa County Department of Health. The deceased patient is not one of the two who developed HUS.

The CDC said the number of cases could rise because it usually takes between three and four weeks to determine whether an illness is linked to an outbreak. Additionally, the actual number may be higher because many people recover without medical care and are not tested for E. coli, the CDC said.

Of the people interviewed by the CDC who became ill, most reported eating the Quarter Pounder hamburger at McDonald’s before becoming ill.

Epidemiological and traceback data show that fresh, slivered onions used on the Quarter Pounder and other menu items are the likely source of the outbreak, the CDC said.

McDonald’s stopped using chopped onions on its Quarter Pounder hamburger in some states to prevent more people from getting sick.

In addition, Taylor Farms, the supplier of chopped onions to affected McDonald’s locations, also recalled yellow onions, the CDC said.

All of the newly reported illnesses occurred before McDonald’s and Taylor Farms took action to remove onions from McDonald’s locations.

After ceasing distribution of Quarter Pounder beef patties in affected areas last week, McDonald’s is now asking their beef suppliers to produce a new supply of fresh patties to resume distribution.

The Quarter Pounder is expected to be available in all restaurants in the coming week company update on Sunday.

The CDC recommends that those who have severe E. coli symptoms — including bloody diarrhea, fever greater than 102 F, and vomiting — contact a healthcare provider immediately.

Youri Benadjaoud of ABC News contributed to this report.