Are Listeria recalls on the rise or are we just hearing more about them?

A microbiologist is pictured pulling Listeria bacteria from a tube in this 2013 file photo. (AP Photo/David Goldman)

Consumers in Canada are being told to check their freezers after hundreds of frozen waffle products were recalled for fears of a possible Listeria contamination. The voluntary recall was just the latest in a string of listeria-related recalls in North America.

The breakfast food recall was initiated by TreeHouse foods, after the U.S.-based manufacturer found possible Listeria contamination during routine testing.

In Canada, those brands include Great Value, Compliments and No Name.

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“It’s liquid batter being piped through who knows how many metres and metres of piping,” says Lori Burrows, a microbiologist and professor at McMaster University. “It’s very difficult to clean that kind of system down the last microbe.”

This recall is just the latest in a string of Listeria-related product summons in North America. In July, a number of plant-based beverages were recalled after people fell ill after consuming them. The Canadian Food Inspection Agency says at least 20 Listeria infections were linked to contaminated beverages. Fifteen people were hospitalized and three died.

In the case of the waffles, no illnesses have been reported and the possible Listeria contamination was found during testing. Experts say this is evidence that safeguards that have been put in place are working.

“This is where we kind of lean on our government to enforce regulations about food safety,

Burrows says. “How often and how well plants are sanitized and regular inspections are key because you have to keep people accountable.”

But others say, in an ideal world, contamination should be found before products ever leave the factory.

“It's still a little bit like closing the barn door after the horse has escaped,” says Lawrence Goodridge, the director of the Canadian Research Institute for Food Safety at the University of Guelph. He adds it’s not enough for companies to simply comply with regulations.

“If food producers are simply following the regulations because they have to follow the regulations than that is one indicator there will likely be problems,” he says. “Food producers need to develop a culture of food safety.”

While data is still coming in for this year, Goodridge says Listeria outbreaks seem to be on the rise.

“Anecdotally, it appears there have been more Listeria outbreaks,” he says.

There are many reasons why Listeria recalls and outbreaks may be increasing – an interconnected supply chain, more consumption of processed foods and high worker turnover in production facilities, Goodridge explains. Food production is not an easy job and there can be gaps in training new workers.

“It’s never just one thing that leads to an outbreak,” says Goodridge.

It could also be that the public is hearing more about them.

There is “better reporting and tracing,” says Darin Detwiler, a food safety advisor and professor at Northeastern University. “The complexity of the food supply chain, including the handling of ready-to-eat and refrigerated products, increases the risk of contamination, especially when there are gaps in cold chain management or sanitation protocols.”

Listeriosis is a foodborne bacterial illness that can cause severe, potentially fatal, infections in young children, frail or elderly people, and others with weakened immune systems. The infection can also result in miscarriages and stillbirths.

Infected individuals in good health may experience less severe, short-term symptoms including high fever, severe headache, stiffness, nausea, abdominal pain and diarrhea.

Anyone with affected products is encouraged to either throw them out or return them for a full refund.