Some restaurants in Canada have stopped serving dishes with romaine lettuce after a deadly E. coli outbreak has been linked to the leafy vegetable.

There are 41 cases of E-coli under investigation by the Canadian Food Inspection Agency in Ontario, Quebec, New Brunswick, Nova Scotia, and Newfoundland and Labrador as of Dec. 28.

Seventeen people have been hospitalized and one person has died. In most cases, those affected were female.

Cara Operations Ltd., which operates Swiss Chalet, Milestones Grill + Bar, Montana’s Cookhouse, Kelsey’s, East Side Mario’s and other chains, has instructed certain locations to stop using romaine lettuce.

Boston Pizza has also discontinued the use of the greens at locations in the affected provinces.

So far, there is no evidence to suggest that provinces in western Canada are affected by the outbreak.

Although anyone can get an E. coli infection, pregnant women, those with weakened immune systems, young children and older adults are most at risk for developing serious complications.

Some people infected with E. coli may not get sick at all but others may experience symptoms within one to ten days after contact with the bacteria. Those symptoms can include nausea, vomiting, headache, mild fever, severe stomach cramps and watery or bloody diarrhea.

For more information about the investigation and for food safety tips for lettuce that will help you reduce your risk of getting an E. coli infection, click here.