A study conducted by the University of British Columbia and published in the journal Food Microbiology has found Listeria bacteria in 20% of ready-to-eat (RTE) fish products sold in Vancouver, British Columbia. The products were not named, nor were the stores where they were purchased.
The researchers tested smoked tuna, candied salmon, lox, and fish jerky. Five of the products had the variety Listeria monocytogenes, which can cause serious illness and death.
While the levels of bacteria meet Canadian federal guidelines, the bacteria can multiply in food while it’s being shipped and while it sits on store shelves and in consumer’s homes. This can be especially problematic toward the end of a product’s shelf life.
The Canadian guidelines limit Listeria in food to 100 cells per gram, since that level is considered to be very low risk.
In the United States, it’s illegal to sell any ready-to-eat food contaminated with Listeria. In fact, the FDA recently held cold-smoked salmon from the market after Listeria was found in that product.
The bacteria is destroyed by cooking, but the whole point of ready-to-eat products is that you can, well, eat them without heating. Anyone in a high risk group, such as pregnant women, the elderly, young children, those with a compromised immune system, and anyone with a chronic illness should be cautious when consuming ready-to-eat foods.
Listeriosis, the disease caused by Listeria, is fatal in about 20 to 40% of all cases. It also causes miscarriages and stillbirths in pregnant women.
