Canadian officials are advising the public to avoid eating romaine lettuce until further notice because of an expanding E. coli outbreak, but they have not revealed the supplier or brands involved.

At least one person has died and 40 have been confirmed infected with E. coli O157:H7. Sixteen have required hospitalization. Onset of their symptoms  range from mid-November through early December. There is a lag between when people become ill and when the government records a confirmed outbreak case, so additional victims are likely to be identified.

No one has recalled romaine lettuce in connection with the outbreak, so contaminated product could still be in consumers’ homes, as well as restaurants, grocery stores, foodservice operations, distribution centers and other points in the food supply chain. Romaine’s shelf life of up to five weeks prompted health officials to urge people to discard all romaine lettuce.

“There appears to be an ongoing risk of E. coli infections associated with the consumption of romaine lettuce,” according to an update posted today by the Public Health Agency of Canada (PHAC).

“Individuals in Ontario, Quebec, New Brunswick, Nova Scotia, and Newfoundland and Labrador are advised to consider consuming other types of lettuce, instead of romaine lettuce, until more is known about the outbreak and the cause of contamination.

“… exposure to romaine lettuce has been identified as the source of the outbreak, but the cause of contamination has not been identified.”

Ongoing threat
In the past week, 10 more victims have been identified. The initial outbreak notice, posted Dec. 11, reported 21 confirmed victims.

“These illnesses indicate that contaminated romaine lettuce may still be on the market — including in restaurants, grocery stores and any establishments that serve food,” PHAC reported today.

Outbreak victims reported eating romaine lettuce at home, as well as in prepared salads purchased at grocery stores, restaurants and fast food chains, according to the outbreak update. Public health investigators are working with the Canadian Food Inspection Agency to determine the source of the romaine lettuce that ill individuals were exposed to.

That source is most likely the United States, or possibly Mexico, based on growing seasons and existing supply chain patterns. Between the relatively limited number of possible suppliers and government traceability requirements, the lack of information from Canadian officials is “perplexing” as far as food safety attorney Bill Marler is concerned.

“This outbreak has been going on for weeks and it’s perplexing that a lettuce source has not been named,” said the Seattle attorney who has been representing victims of food poisoning since the deadly 1993 Jack in the Box E. coli outbreak.

“Canada has a very sophisticated surveillance system, similar to the U.S. That raises concerns because if you don’t know where the lettuce is coming from, you don’t know if there is an ongoing threat.”

Even if the grower of the implicated romaine lettuce has harvested the last crop of the season, the E. coli risks can continue. Growing fields could be contaminated, thus contaminating the next crop to be rotated in, and packing/processing facilities could be the source of the pathogen. If that’s the case, Marler said other fresh produce commodities could be contaminated in the facilities.

It remains unknown if whole heads of romaine or chopped, bagged romaine — or both — are implicated in the current outbreak. Canadian officials have not revealed those details. No products have been recalled.

Advice to consumers
Although anyone can contract an E. coli infection, pregnant women, people with weakened immune systems, young children and older adults are most at risk for developing fatal infections or severe complications.

Anyone who has eaten romaine lettuce and developed symptoms of E. coli infection should immediately seek medical attention. Specific lab test are required to diagnose E. coli infection.

Symptoms can include nausea, vomiting, headache, mild fever, severe stomach cramps, and watery or bloody diarrhea. The onset of symptoms can range from 1 to 10 days after exposure.

“Some do not get sick at all, though they can still spread the infection to others. Others may feel as though they have a bad case of upset stomach. In some cases, individuals become seriously ill and must be hospitalized,” according to the health agency notice.

People who develop hemolytic uremic syndrome (HUS) need intensive medical treatment, usually including dialysis for kidney failure.

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