One person is dead and more than 120 people across the country have now been reported ill from the E. coli outbreak linked to romaine lettuce.
A total of 121 cases have been identified in 25 states. More than half of those people have been hospitalized.
The death was reported in California.
The number of people who are sick might go up further because it takes an average of two to three weeks between when a person becomes sick with E. coli and when the illness is reported.
No one should buy or eat any romaine lettuce from the Yuma, Arizona growing region, officials said.
While most strains of the bacteria E. coli are harmless, others can cause serious illness. The strain linked to chopped romain lettuce is a Shinga toxin-producing E. coli, which can cause severe stomach cramps, diarrhea and vomiting, the CDC said.
E. Coli can be spread through consuming contaminated water or food or through contact with infected people or animals.
Most people start feeling sick a few days after eating or drinking food contaminated with the bacteria, but it can take up to 10 days for symptoms to start. Patients usually get better within 5 to 7 days.
If diarrhea lasts more than three days or is accompanied by high fever, blood in the stool or so much vomiting that the patient cannot keep down liquids, a doctor must be called, the agency said.
This current outbreak is not related to the recent multi-state outbreak of E. coli that had been linked to leafy greens in December 2017. In that instance, 25 people were sickened and one person died.