An expert is advising Manitobans to avoid eating romaine lettuce after an E. coli outbreak sickened a number of Canadians and Americans.

According to the Public Health Agency of Canada, the outbreak caused 15 people in Quebec and three in Ontario to fall ill, with six ending up in the hospital. No deaths have been reported. An advisory from the agency warned people in those provinces to avoid eating romaine, but a food sciences professor said Manitobans should also take heed.

“I would say you shouldn’t consume,” said Claudia Narvaez, the University of Manitoba. “Avoid it for now until we know.”

In the U.S., 32 cases of E. coli have been reported, with 13 people hospitalized.

“Those who are most at risk are those who are really young, elderly people or those who have immune system compromised,” said Celine Nadon, chief of surveillance, outbreak detection and response for the National Microbiology Laboratory’s division of enteric diseases.

Narvaez said E. coli easily attaches to the surface of romaine lettuce, and can stay attached even after it’s washed.

“It’s a pretty serious bacteria, you don’t want to take a risk on it.”

The strain identified in this outbreak, E.coli O157, appears to be similar to one that was linked to the leafy vegetable last year. Romaine lettuce is susceptible to E.coli because it is in the environment where it’s grown, through things like animals and manure.

For the current outbreak, the Canadian Food Inspection Agency said it is working with authorities in the United States to try to determine the source of the lettuce that is making people sick. The agency said if the contaminated products are found in Canada, they will take the proper steps to keep the public safe.

“For all Canadians it’s important for everyone to pay attention, especially when we don’t have all the answers quite yet,” said Nadon.

Though most E.coli bacteria are benign it can cause sickness. The symptoms include stomach cramps, diarrhea and vomiting. Usually people recover within a week, but the illness can be more severe and last longer.

No cases have been reported in Manitoba.

- With files from CTV’s Michelle Gerwing and The Canadian Press