E. coli outbreak: Should Canadians keep eating romaine lettuce?

On Wednesday, federal health officials issued a warning that six Canadians had fallen sick with a strain of E. coli that is similar to one that has sickened 149 people across the United States, and killed one.

But, officials say that there is no reason Canadians should stop eating romaine lettuce.

READ MORE: E. coli in romaine lettuce makes 6 Canadians sick

Here’s what we know – and don’t – about Canada’s response to the outbreak.

About the cases

Six people got sick from this particular strain of E. coli, according to the Public Health Agency of Canada (PHAC). One was from B.C., one from Alberta, two from Saskatchewan, and two from Ontario. They got sick between late March and mid-April.

One person was hospitalized. No deaths have been reported in Canada.

PHAC believes that the likely source of this outbreak is romaine lettuce. This is a separate lettuce-linked outbreak from a previous one this winter.

About the lettuce

The source of this outbreak in the U.S., according to the Centers for Disease Control and Prevention, might be lettuce from the Yuma region, which is largely in Arizona.

Two of the Canadians who were infected had travelled to the U.S. and eaten lettuce there. The others had stayed in Canada, and reported eating romaine lettuce at home or in a prepared salad from a store, fast food outlet or at a restaurant.

However, according to Dr. Howard Njoo, deputy chief public health officer of Canada, “In this case there has been no evidence or information that we’ve received that there is contaminated lettuce found in Canada.”

READ MORE: One dead in E. coli outbreak linked to romaine lettuce in the U.S.

He did not clarify how these Canadians were infected if they didn’t travel to the U.S. and there is no evidence of contaminated lettuce in Canada.

Canada imported 22 million kilograms of lettuce from Arizona between January and March of 2018, according to data from Agriculture and Agri-Food Canada, though the data doesn’t say which region it came from. The Yuma region accounts for 90 per cent of the leafy vegetables grown in the United States from November to March, according to the local chamber of commerce.

PHAC also isn’t sure if the E. coli cases are linked to lettuce from the Yuma region, although they have a “similar genetic fingerprint” to the U.S. E. coli cases.

Additionally, said Njoo, “There are individuals who were infected in Canada but there is not enough information we have to implicate any specific brands.”

Why there is no recall in Canada

Without a specific brand or source, the Canadian Food Inspection Agency (CFIA) can’t issue a recall, Natasha Gauthier, an agency spokesperson explained.

“We cannot do a recall without having identified what product needs to be recalled.”

And they won’t issue a general warning – such as not to eat romaine lettuce – unless there is a recall attached. “It sends a mixed message. If it’s not safe to eat, why aren’t you recalling it?”

The CDC has issued a warning like this though. On their website, they clearly tell consumers, “Do not eat or buy romaine lettuce unless you can confirm it is not from the Yuma growing region.”

This advice goes for whole lettuce, hearts of lettuce and salad mixes.

WATCH: Deputy chief public health officer Howard Njoo says Canada hasn’t yet been able to identify and specific brands of lettuce for a possible recall.

Is romaine lettuce safe to eat?

Njoo says it is.

“At the present time there is no information to indicate that it’s not safe to consume lettuce in Canada.”

Because it’s a leafy vegetable that isn’t cooked, PHAC urges Canadians to always wash their hands before and after handling romaine lettuce, remove its outer leaves, and wash it under running cold water until all visible dirt has gone before eating it.

Canada has cases of E. coli related to lettuce throughout the year, so PHAC recommends that people always take these steps, whether or not an outbreak is in the news.

As for lettuce from the Yuma region, “We do know from our American colleagues that the Yuma region stopped producing and distributing lettuce quite some time ago, mid-April, I believe,” said Njoo. “And given the short shelf life, it’s about 21 days, the actual probability risk of any Yuma-grown lettuce being on the shelves in Canada at this point in time is quite low.”

WATCH: Should you be throwing out your Romaine lettuce?

Although he also believes the risk to be low, Sylvain Charlebois, a professor in food distribution and policy at Dalhousie University, says that he doubts many Canadians will keep eating romaine lettuce after this warning.

“I do expect a lot of Canadian consumers to pass on romaine lettuce for a while again.”

Jeff Farber, director of the Canadian Research Institute for Food Safety at the University of Guelph, said that a lot of confusion could be avoided if products were easier to trace.

“It becomes almost impossible sometimes to find out which farm the product actually came from. It becomes very, very difficult. And unless you know exactly where the product is coming from, then it becomes very difficult for federal officials to actually issue a recall because what are they recalling?” he said.

“I think we all need to do a better job in getting better trace-back information on particular products and where they’re actually – what the origin of these products actually is.”