E. coli outbreak in Canada, women at higher risk
The number of cases under investigation doubled in the past month to 40, the agency said, adding that "there appears to be an ongoing risk" of infection.
Individuals who became ill were between the ages of four and 85 years of age, and most (73 percent) were female. Sixteen people have been hospitalized.
They reported having eaten romaine lettuce at home, as well as in prepared salads from grocery stores, restaurants and fast food chains, before symptoms arose.
The contamination has now also spread to five eastern provinces, including Quebec and Ontario.
In a statement, the public health agency urged consumers to "consider consuming other types of lettuce, instead of romaine lettuce, until more is known about the outbreak and the cause of the contamination."
"These illnesses indicate that contaminated romaine lettuce may still be on the market," it added.
© 2017 AFP