An Illinois resident has become ill from E. coli found in chopped romaine lettuce, marking the first Illinois case of an outbreak that has sickened 35 people nationwide.

The outbreak of E. coli has hospitalized 22 people in 11 states, according to the Illinois Department of Public Health. In the Illinois case, the person reported eating chopped romaine lettuce before becoming ill.

Health officials have narrowed down the origin of the outbreak to romaine lettuce produced in Yuma, Arizona. No common grower, supplier, distributor or brand has been identified.

The health department warned consumers to throw away store-bought chopped romaine lettuce, even if some of it was already eaten and no one became ill.

Before purchasing romaine lettuce at a grocery store or restaurant, consumers should confirm that the lettuce is not from the Yuma region, the health department said.

People who consume the E. coli germ usually become sick two to eights days later, the department said. Symptoms of an infection include diarrhea, severe stomach cramps and vomiting.

Most people recover from E. coli within about a week, but some illnesses can be more severe and result in a type of kidney failure called hemolytic uremic syndrome, according to the health department.