E. coli symptoms include diarrhea, severe stomach cramps, vomiting or low fever and signs of dehydration, according to the Douglas County Health Department. Blood and urine may be present in the stool. If someone experiences symptoms for more than two days, health officials recommend contacting a doctor immediately.

State and county health officials in Nebraska say they are working closely with the U.S. Centers for Disease Control and Prevention, the U.S. Department of Agriculture’s Food Safety and Inspection Service and the Food and Drug Administration (FDA) to communicate with patients and other identify potential cases. .

However, the CDC does not recommend against eating McDonald’s food, but says potentially contaminated items have been removed from the menu in affected states.

An explanation from McDonald’s said that out of “an abundance of caution,” it is temporarily removing the Quarter Pounder from restaurants in the affected area, including Colorado, Kansas, Utah and Wyoming, as well as parts of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico and Oklahoma .

“We take food safety very seriously and it is the right thing to do,” said the statement from Cesar Piña, Chief Supply Chain Officer of the fast food restaurant North America.

McDonald’s said initial findings indicate that some of the illnesses may be linked to chopped onions used in the Quarter Pounder, which come from a single supplier serving three distribution centers.

It says local restaurants have been ordered to remove that product from their offerings and McDonald’s has stopped distributing all chopped onions in the affected area.

USDA is also investigating the beef patties on Quarter Pounder burgers, Colorado officials said.

McDonald’s said it is working with suppliers to replenish inventory for the Quarter Pounder in the coming weeks. It said other menu items are unaffected and available.

Infections probably higher than reported

After exposure to STEC, symptoms usually appear after three to four days, but can last from as little as one day to as long as 10 days, Nebraska health officials said.

STEC infections can make people of all ages sick. In some cases, especially in young children, older adults, or people with weakened immune systems, STEC can cause a serious condition called hemolytic uremic syndrome (HUS), which can lead to kidney failure and other health problems, including death.

One of the individuals infected in the outbreak developed hemolytic uremic syndrome. Symptoms include little or no urination, loss of pink color on the cheeks and lower eyelids, unexplained bruising or rash with small red spots, blood in the urine and reduced alertness.

The CDC said the actual number of people sick in the outbreak is likely much higher than the reported number, and the outbreak may not be limited to states with known illnesses. The federal agency said this is because many people recover without medical care and are not tested for E. coli.

In addition, recent illnesses may not yet be reported, as it typically takes three to four weeks to determine whether a sick person is part of an outbreak.

More information can be found on the CDC website.