Romaine lettuce "particularly sensitive" to E. coli outbreaks

Grocery stores have removed romaine lettuce from their shelves and many restaurants have stopped serving Caesar salads after leafy green has been associated with an outbreak of E. Coli for the third time in about a year.

Lettuce is more susceptible to E. coli contamination, in part because of its culture, and its increasingly tarnished image could undermine consumer confidence: do not buy green salad even after the reappearance of uncontaminated products in shops and restaurant tables.

"Romaine lettuce is particularly susceptible," said Keith Warriner, a professor at the University of Guelph. "In our own research, we found that E. Coli loved romaine lettuce among all the other lettuces we have. "

19 confirmed cases of E. coli infection were investigated in Ontario, Quebec and New Brunswick on Wednesday, announced the Public Health Agency of Canada in a public health notice. The patients are between 5 and 93 years old and most of the reported cases consume romaine lettuce before having symptoms.

Read more:

Warriner conducted a study that showed that romaine lettuce extracts induced E. coli to come out of the dormant state, in which it can stay about a year in the soil, and allowed it to thrive.

The increased susceptibility of Romaine depends on several factors, he said.

The crop is mainly grown in Arizona and California, said Warriner, who is also a country of breeding. Irrigation water used on Roman fields can be contaminated by animal bacteria. This does not help that the two states are hot enough and the romaine lettuce already requires an abundance of water, he said.

While other crops such as spinach and kale are also grown in these areas under similar conditions, these leaves are "hard as fingernails", he said, and can better withstand damage.

Centralized production also means that if an epidemic breaks out, it will spread as the product is sent across Canada and the United States, he said.

Finally, washing lettuce at home does nothing, says Warriner, and "more likely to recontaminate than decontaminate". Not to mention that the product is consumed raw, which means that cooking can not kill any bacteria.

The recalls raise a lot of mistrust of consumer confidence in the food chain, said Katy Jones, marketing director at FoodLogiQ, based in North Carolina. The company offers technology that helps food companies track their supply chain and respond effectively to recalls.

Some consumers have complained on Twitter of having been systematically encouraged to throw away expensive packages of products containing romaine. Others said that they had long since stopped buying the lettuce variety.

This is reminiscent of a 2006 outbreak of E. coli related to spinach, Jones said. In the United States, 199 people were infected and three died, according to the CDC. Canada had at least one confirmed case.

Some have speculated that this incident led consumers to avoid spinach in favor of kale, she said. The so-called superfood has seen a meteoric rise with kale cookbooks featuring Caesar-flavored Caesar Salad and Salad recipes making food a must-have.

But consumers tend to continue to buy from companies that handle these recalls well, Jones said, which means honestly and responsibly.

"Unlike some other types of recalls, we see where they hang out for weeks," she said. "That's what will boost consumer confidence if businesses have a head start."