Frozen waffles recalled in Canada and U.S. over listeria concerns: What is listeria, and what are the symptoms?

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Waffle products sold in Canada and the U.S. are being recalled due to fears of listeria contamination. On Oct. 18, TreeHouse Foods announced it was voluntarily recalling hundreds of frozen waffle products under various brand names following “routine testing at the manufacturing facility” in Ontario.

According to a press release, the Canadian Food Inspection Agency (CFIA) and U.S. Food and Drug Administration (U.S. FDA) is aware of the voluntary recall. The CFIA has yet to issue a recall notice on its website and to date, there have been no confirmed reports of illness linked to the recalled products.

What frozen waffles were recalled?

A complete list of products included in the recall — including associated lot codes— can be found at the bottom of TreeHouse Foods’ press release. Photos of the products associated with the recall are available online.

Recalled products include the brands:

• No Name

• Great Value

• Selection

• Compliments

• Breastfast Best

• Western Family

• Always Save

• Best Choice

• Bettergoods

• Clover Valley

• Essentials

• Food Lion

• Food Hold

• Giant Eagle

• Good & Gather

• Hannaford

• Harris Teeter

• H-E-B Higher Harvest

• Kodiak Cakes

• Pics by Price Chopper

• Publix, Schnucks

• SE Grocers

• Simple Truth

• Tops

What exactly is listeria and why is it dangerous if consumed? Here's what you need to know —and symptoms of listeria to look out for.

What is listeria?

Dr. Isaac Bogoch, an infectious diseases specialist at the Toronto General Hospital, described listeria as a type of bacteria that can infect people when they consume contaminated food.

"It's usually associated with specific types of food," said Bogoch in a September 2023 interview. "It's just more common in some foods than others. But it's sadly not uncommon to hear about listeria outbreaks from time to time."

He said listeria can be found in:

• Cold cuts, deli meats and hot dogs

• Pasteurized or unpasteurized milk products

• Store-made salads

• Occasionally, in fruits and vegetables

"The interesting thing about listeria is that, normally when you put something in the refrigerator, it usually would suppress bacterial growth, but listeria actually grows very well in refrigerated environments," Bogoch explained.

What are the symptoms of a listeria infection?

The Canadian Food Inspection Agency said food contaminated with listeria may not look or smell spoiled, but can still make people sick.

According to public health, symptoms of listeria can start as early as three days after eating contaminated food.

The symptoms can include the following:

• Fever

• Nausea

• Cramps

• Diarrhea

• Vomiting

• Headache

• Constipation

• Muscle aches

"Most people who get listeria are going to have diarrhea and gastrointestinal symptoms. It's going to go away on its own. They don't even require antibiotics. ... And a lot of people probably had listeria and did not even know it," said Bogoch.

Is listeria dangerous for everyone?

Pregnant women, the elderly and people with weakened immune systems are particularly at risk for severe illness from listeria, according to Bogoch.

"Those individuals are at risk of what we call invasive listeriosis," said Bogoch. "And that means it can cause a bloodstream infection. ... it can be very serious."

According to the World Health Organization (WHO), invasive listeriosis is characterized by "severe symptoms and a high mortality rate (20 to 30 per cent)."

The symptoms include:

• Fever

• Myalgia (muscle pain)

• Septicemia (blood poisoning)

• Meningitis (inflammation of brain and spinal cord tissues)

"The incubation period is usually one to two weeks but can vary between a few days and up to 90 days," WHO explained.

The infection in pregnant women may also lead to premature delivery, infection of the newborn or even stillbirth.

However, Bogoch said listeria is generally not difficult to treat and people who do end up hospitalized will get antibiotic therapy.

"The key is prevention," he added, "to ensure that people are aware of what product is involved so they can avoid it ... and if people do have risk factors for a severe infection and they have symptoms of infection, to ensure that there is rapid access to care and they start treatment."

Is listeria contagious?

People become infected by listeria by consuming contaminated products. Listeria infections don't spread from person to person. However, it's possible for a pregnant person to pass a listeria infection to their unborn fetus.

How to prevent listeria infection

Bogoch said food contaminated with listeria is beyond an individual's control and it has to do with how the food was processed before it reached the consumer. But, there are still ways to prevent infection.

"People can cook their meat. ... The bacteria would not survive if you cooked a hot dog," said Bogoch.

Health Canada said "foods that are contaminated with the listeria bacteria will look, smell and taste normal."

This is why people at high risk for severe illness should avoid eating deli meats unless they are dried and salted, or heated until steaming hot. Additionally, they should avoid pâté and meat spreads unless they are frozen, canned or shelf-stable.

To lower the risk of infection, Bogoch also recommended people avoid unpasteurized dairy products, which Health Canada said includes soft and semi-soft cheese such as brie, camembert and blue-veined cheese.

"People can still get listeria through pasteurized products ... but unpasteurized products carry a higher risk," Bogoch said.

Fruits and vegetables should also be washed thoroughly, the doctor concluded.

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