A UBC study has found traces of the bacteria Listeria in ready-to-eat fish products sold in Metro Vancouver.
Certain strains of Listeria are known to cause listeriosis which can lead to serious illness or even death. In 2008, 23 Canadians died from eating deli meats tainted with Listeria monocytogenes.
Food microbiologist Kevin Allen tested 40 ready-to-eat fish samples prior to their best before date. Purchased from seven large chain stores and 10 small retailers in Metro Vancouver, these products included lox, smoked tuna, candied salmon and fish jerky.
The findings – published in a recent issue of the journal Food Microbiology – shows that Listeria was present in 20 per cent of the ready-to-eat fish products. Of these, five per cent had the more virulent variety Listeria monocytogenes.
Eating foods spoiled with Listeria monocytogenes can cause illness ranging from diarrhea to vomiting. Listeriosis infection can also result in brain and blood infections and is fatal in an estimated 20-40 per cent of cases.
“What this means for consumers is that pregnant women, the elderly and anyone with a compromised immune system should be aware of the health risks,” said Allen. “While Listeria bacteria can be killed by high heat, most people tend to eat these fish products without further cooking.”
An assistant professor in LFS, Allen led the study with co-authors Lili Mesak (PhD student) and Jovana Kovačevic (Research Assistant).
The researchers also tested ready-to-eat meat products from the same Metro Vancouver retailers where they bought the fish. However, they didn’t find Listeria bacteria in any of the 40 meat samples which included bologna, corned beef, cooked ham and pepperoni.