The alert comes after a reported 32 people in 11 states became ill from eating contaminated romaine. No deaths have been reported, it said.
The contaminated lettuce is from the Yuma, Arizona region.
Consumers and retailers should throw away romaine lettuce even if some of it has been consumed and no one has gotten sick. One of the hospitalized people developed hemolytic uremic syndrome, a potentially life-threatening form of kidney failure. At least 13 people were hospitalized for illnesses that began between October 8 and October 31, the CDC says.
Several similar romaine lettuce E.coli cases have been reported across Canadian provinces in the past few months.
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But, at some point during the incident, the woman claims Hayne's actions turned criminal and she suffered injuries as a result. Police allege the assault of the 26-year-old woman took place in a Hunter region home on September 30.
The US Food and Drug Administration and the CDC traced the origin of that contamination to irrigation water in the Yuma, Arizona, growing region.
That outbreak investigation was declared closed in February 2018 after nearly two months during which no illnesses were reported and various romaine lettuce samples tested negative for E. coli. Because the CDC hasn't named a common grower or supplier, all brands are suspect.
This investigation is ongoing, and the CDC will provide more information as it becomes available. If you're unsure about whether or not the contents of your lettuce contains romaine, you're advised to throw it out anyway.
Symptoms of E. coli infection, which usually begin about three or four days after consuming the bacteria, can include watery or bloody diarrhea, fever, abdominal cramps, nausea and vomiting. California and MI have the most reported cases (10 and 7, respectively).