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

‘An emporium’: Pennyroyalty Thrift

A tour of shops in Hope and Fraser Canyon giving old stuff a new lease on life

Retail sales of cannabis prohibited in Hope, for now

Councillors want more public feedback as provincial regulations are expected by October

It’s about to get hot: Special weather statement issued for Lower Mainland

Temperatures expected to rise and stick around till next week, Environment Canada forecasts

France doubles up Croatia 4-2 to win World Cup

Played in Moscow Russia, latest Fifa World Cup marks the highest scoring final since 1966

WATCH: Boothroyd Band now home to a Native American medicine wheel

Former chief Rick Campbell to guide people through the wheel in his art therapy practice

REPLAY: B.C.’s best video this week

In case you missed it, here’s a look at replay-worthy highlights from across the province this week

Former NHL goalie Ray Emery drowns in Lake Ontario

Police say the 35-year-old’s death appears to be a ‘case of misadventure’

Air quality statement warns of smoky air for Kamloops area

Environment ministry says area on north side of Thompson River may be affected by wildfire smoke

Pussy Riot claims on-field protest at World Cup final

Russian protest group claimed responsibility after four people ran onto field in police uniforms

Fans party on Montreal streets after French World Cup win

To city is home to nearly 57,000 French nationals

SilverStar officially opens Gondola

The brand-new gondola is now offering scenic rides for visitors on SilverStar Mountain Resort.

VIDEO: Man climbs crane in Abbotsford

Police, fire called to deal with climber last night

VIDEO: Langley City legendary water fight was a soaking good time

And perfectly timed for a hot weather warning

B.C. VIEWS: Making private health care illegal again

Adrian Dix battles to maintain Cuba-style medical monopoly

Most Read