While the lettuce has been infected with E.Coli in the US - in an outbreak that has sent 31 people to hospital in recent weeks - no traces of the bacteria appears to have affected Canadian produce, the agency said. An update issued on Friday, however, says customers should also avoid whole heads and hearts of romaine, in addition to chopped lettuce, unless they can determine that it was not grown in Yuma.
The previous alerts just applied to sliced romaine on its own and as component of tossed salads & mixed greens.
The warning stated that restaurants and retailers "should not serve or sell any romaine lettuce from the Yuma, Arizona, growing region".
The CDC has expanded its warning.
Three Montanans have been hospitalized for treatment of E. coli O157:H7, the strain linked to lettuce from Arizona, said Alisha Johnson, environmental health specialist with the Missoula City-County Health Department. The warning includes all romaine lettuce, hearts, and salad mixes containing romaine. Investigations revealed they had eaten whole heads of romaine lettuce from the Yuma, Arizona growing region. Symptoms of infection include bad stomach cramps, diarrhea (often bloody) and vomiting.
No common grower, supplier, distributor or brand has yet been identified.
The different ways that romaine lettuce is harvested could make identifying the specific origin of contamination more hard, Marler said.
Neighboring Idaho has reported 10 cases, according to the Centers for Disease Control. For some, the illness may include a fever. Most people recover within a week, though one of the most serious complications, a type of kidney failure called hemolytic uremic syndrome, can develop about seven days after symptoms first appear. Symptoms of hemolytic uremic syndrome include less urination, feeling very exhausted, and losing color in the cheeks.