Are the packed salads and deli meat you buy in Canada safe for consumption? Most likely yes.
So far this year, at least 21 food items from different companies have been recalled by the Canadian Food Inspection Agency (CFIA) due to Listeria concerns.
In the month of August alone, 10 products, including chopped salads, mushrooms, vegetable noodles, vegetable stir fry kits and cheese, were taken off store shelves.
In 2020, 12 products triggered a recall warning and in the year before that 53, according to the government website.
Listeria monocytogenes is a type of bacteria commonly found in soil and it causes food-borne illnesses in humans.
So far, no illnesses have been reported for any of the products flagged by CFIA this year, but upon consumption, there is a risk of infection.
“The important thing to know with Listeria is basically that it is very widespread in nature, so you can find it in many, many different places,” said Jeff Farber, professor of food science at the University of Guelph.
How does Listeria contamination happen?
Listeria can live in a food plant for several years. Farber called it a “permanent colonizer or resident in the food plant.”
Because the bacteria can establish itself inside the environment of the plant, it becomes very difficult for the food industry to get rid of it, Farber explained.
For the most part, “post-processing contamination” takes place with Listeria, he said. That means after the product is heated, it gets exposed to the environment and because Listeria is so common in the environment, that food product gets contaminated with it.
“It’s a bacteria that’s found everywhere, so many foods can become contaminated with Listeria,” said Lawrence Goodridge, director of the Canadian Research Institute for Food Safety at the University of Guelph.
Foods that are more susceptible to Listeria contamination include: soft cheeses, unpasteurized (raw) milk, deli meats, raw or undercooked meat, poultry and fish as well as refrigerated smoked seafood.
What are the risks?
Food contaminated with Listeria may not look or smell spoiled but can still make you sick, CFIA says.
Farber said it was important to note that in most cases, a high number of Listeria in food is actually needed to cause illness.
In 2008, Canada experienced its worst listeriosis outbreak, with 57 total cases confirmed and 22 deaths traced back to deli meats produced at a Maple Leaf Foods facility in Toronto, Ont.
More recently, between November 2017 and June 2019, seven cases in British Columbia, Manitoba and Ontario were reported, with all but one hospitalized.
While Listeria infections are rare, the risks are greatest for pregnant women, their unborn children, newborns, elderly and people with weak immune systems.
Other healthier individuals are probably ingesting small amounts of Listeria on a daily basis without getting affected, Farber said.
“For most of us (that are) healthy and let’s say less than 65 years of age … we can easily fight off the organism.”
But Listeria contamination can get “very dangerous” for the high-risk population, he added.
Typical symptoms associated with Listeria illness include gastrointestinal problems — like diarrhea, abdominal cramps, nausea, vomiting — as well as fever, muscle aches, neck stiffness and severe headache. In serious cases, it could even cause deaths.
Although infected pregnant women may experience only mild, flu-like symptoms, the infection can lead to premature delivery, infection of the newborn or even stillbirth, according to CFIA.
Elderly individuals or those who receive immunosuppressive treatments can develop septicemia, meningitis and menangle encephalitis, Farber said. Listeria can also grow in their blood and cause high fever.
Can it be prevented?
Good sanitation practices can help prevent Listeria outbreaks. This can include using adequate equipment that can be taken apart so it can be cleaned right down to the bowels, said Farber.
He said it was also important to keep sections of the food plant that handle raw items separate from the site that contains cooked food.
An environmental monitoring program, meanwhile, which can include swab tests, helps detect any presence of Listeria species on contact surfaces.
And once Listeria is found, Farber said, “We have to pay even more attention to sanitizing and disinfecting in this area, so it does not become a problem.”
The temperature at which food is being refrigerated in stores can also promote Listeria growth, Farber said.
“Normally we want to store refrigerated foods at 4 C,” he told Global News.
“But if the stores did not have proper refrigerated cabinets or they’re old, they can go up to seven or 10 C, and in this case, Listeria can actually grow up to higher numbers.”
But the fact that food production companies and the CFIA are frequently recalling contaminated supplies signals that the food safety programs in the country are working, experts say.
“The whole idea of a recall is to remove the foods from circulation so that people do not buy them and consume,” said Goodridge.
Farber agreed, saying, “In general, the food industry has done a very good job in trying to eliminate the organism.”
What can consumers do?
Once a product is recalled, the CFIA advises consumers who may have already bought it to either discard or return to the store for a refund.
“In addition to not eating the recalled product, high-risk individuals should follow safe food handling practices and should always avoid high-risk food items more prone to contamination with Listeria bacteria,” the agency says on its website.
Because salad kits are heavily processed from pre-washing to cutting and mixing, the risk of contamination is greater compared to uncut fresh produce, Goodridge said.
“The more we handle food, the higher the chances that it can be contaminated,” he said.
To decrease the risk of illness, Goodridge recommended consumers buy fresh whole heads of products or uncut produce and prepare their own salads at home.
When shopping, it’s always important to keep an eye on the expiration date for perishable products as well as the general hygiene of the store, Farber said.
To avoid letting the bacteria grow, he also advised consuming packaged salads on the same date of the purchase.