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

No charges for three West Shore RCMP officers after woman’s jaw broken while in custody

After IIO investigation, B.C. Prosecution Service determined case did not meet its charge standard

Elizabeth May arrested at Kinder Morgan protest

Randall Garrison, MP for Esquimalt-Saanich-Sooke, speaks out against pipeline

All-female taxi service eyed for the West Shore

The goal is to help women feel comfortable

Capital Region regular gas prices highest since 2008

Greater Victoria prices roughly 10 cents above the B.C. average

New Galloping Goose overpass at McKenzie could open next week

Drivers reminded to watch the road in McKenzie construction zone

Paralympic dream for rider with cerebral palsy

Kim Scott’s goal is to represent Canada and won’t let anything, including cerebral palsy, get in her way

Comox Valley hospital operating above patient capacity

The new healthcare facility averaged a 110 per cent patient volume between October and February

BREAKING: B.C. mother hit in truck rampage dies

Family confirms mother of four Kelly Sandoval dies almost two months after being hit.

PHOTOS: Students exhibit stunning paper couture dresses

22 paper made gowns will be on display at Vancouver’s Oakridge Centre until March 27

BCHL Today: Prince George avoids elimination with game five win

BCHL Today is a (near) daily look at what’s going on around the league and the junior A world.

Suspect arrested and charged for assault on autistic man

Parmvir Chahil has strong B.C. ties; two others charged with accessory after the fact

Uber self-driving crash video calls safety, rules into question

Experts say footage shows that vehicle’s sensors should have spotted pedestrian, initiated braking

View Royal mayor says Saanich had a take-it-or-leave-it approach to fire dispatch

Re: Communities pull the plug on Saanich fire dispatch. Mayor Richard Atwell… Continue reading

UPDATED: MPs Elizabeth May, Kennedy Stewart arrested at B.C. anti-pipeline protest

The demonstration is part of a day of action against the Trans Mountain expansion

Most Read