A worker harvests romaine lettuce in Salinas, Calif on Aug. 16, 2007. Some restaurant chains have stopped serving dishes with romaine lettuce amid a deadly E. coli outbreak linked to the leafy vegetable.THE CANADIAN PRESS/AP, Paul Sakuma

What you need to know: The lettuce-linked E. coli outbreak

What consumers should know about the romaine lettuce-linked E. coli outbreak

Since mid-November, dozens of people have become ill and two people have died in Canada and the U.S. due to infection with E. coli 0157:H7, which has been linked in this country to contaminated romaine lettuce. Here is a primer on E. coli and what consumers can do to avoid becoming sick:

What is E. coli? Escherichia coli bacteria normally live in the intestines of healthy people and animals and are typically harmless. But infection with the O157:H7 strain, which produces a shiga toxin, can cause severe abdominal cramps, bloody diarrhea and vomiting. Healthy adults usually recover within a week, but young children and older adults have an increased risk of developing a life-threatening type of kidney failure called hemolytic uremic syndrome.

How does contamination occur? E. coli can be shed in the feces of cattle, poultry and other animals, polluting water used to irrigate crops and the soil where fruits and vegetables are grown. Leafy greens, such as lettuce and spinach, can become contaminated during and after harvest from handling, storing and being transported. An individual infected with E. coli also can transmit it to other people.

“This strain of E. coli causes more outbreaks than all other strains combined, so it’s the big problem,” said Herb Schellhorn, a microbiologist at McMaster University in Hamilton, who specializes in the study of E. coli and other water- and food-borne pathogens.

What’s the source of this outbreak? A Canadian Food Inspection Agency-led investigation has determined that romaine lettuce is at the heart of the E. coli outbreak in five eastern provinces, but the source of the produce has not yet been identified. The U.S. Centers for Disease Control has concluded the E. coli involved in 17 cases in 13 states has a closely related genetic signature as the strain behind Canada’s 41 cases, but has not confirmed the food source. One person in Canada and one in the U.S. have died.

“This time of year, most of our lettuce will come from southern places … so if it’s affecting both countries, it may be from California or Mexico or other countries that produce romaine lettuce,” said Schellhorn. ”But it also can be contaminated during the processing by individuals who are infected or if there was fecal contamination introduced at some point in the distribution (process).”

He said the longer it takes to pin down the source of adulteration, the more difficult it will become over time, given that romaine is a perishable item.

“It’s not like it’s frozen and we can go into meat lockers and test food materials for contamination. Depending on how it was contaminated, if it was in one large place and it’s the water that was contaminated, that could have implications for other food materials that might have been exposed.”

While that ”doesn’t appear to be the case” with this outbreak, Schellhorn said E. coli. 0157:H7 is highly infectious and exposure to only a very small amount can cause disease.

What can consumers do? The Public Health Agency of Canada says on its website that thoroughly washing potentially contaminated romaine lettuce — or any other fresh produce — in water can remove the bacteria.

But Schellhorn suggests it’s better to be safe than sorry.

Not only does he advise not purchasing romaine lettuce currently on grocery store shelves, he suggests consumers toss out any they have in the fridge.

“It’s not worth taking a chance … Lettuce isn’t that expensive, it has a short shelf life anyway,” he said.

“I think I would just throw it out.”

Sheryl Ubelacker, The Canadian Press

Like us on Facebook and follow us on Twitter.

Just Posted

Senior denied insurance for lack of a smart phone

Langley woman discovers a deal requires an app

B.C. storm totals $37M in insured damages

The December storm wreaked havoc on B.C.’s south coast

Rising construction costs boost price of Langley intersection project

Bids for Township roundabout came in well over projected costs

Langley-raised catcher to play on Team Canada at Pan Am Games qualifier tournament

Kellin Deglan is headed to Brazil at the end of the month to play ball with Team Canada

Trappers back to peak form

Langley Junior B Team aims for playoffs

Trudeau says politicians shouldn’t prey on Canadians’ fears

The Prime Minister was speaking at a townhall in Ontario

Chiasson nets shootout winner as Oilers edge Canucks 3-2

Edmonton moves one point ahead of Vancouver

B.C. chief says they didn’t give up rights for gas pipeline to be built

Hereditary chief: no elected band council or Crown authority has jurisdiction over Wet’suwet’en land

Thieves steal thousands from 140 Coast Capital Savings members

Online fraud tactics included phising and ‘brute force’ in November and December

Condo rental bans may be on way out with B.C. empty home tax

Many exemptions to tax, but annual declarations required

UPDATE: B.C. boy, aunt missing for three days

The pair are missing from Kamloops

Daredevil changes game plan to jump broken White Rock pier

Brooke Colby tells council daredevil event would help boost waterfront business

Man, two children sent to hospital after Vancouver carbon monoxide leak

Nine people were evacuated from the home in south Vancouver

Dog shot in foot with BB gun during cellphone sale at SkyTrain station

William Ayers, 28, is facing a number of charges after incident in Burnaby

Most Read