A new study has identified traces of the bacteria listeria in ready-to-eat fish products sold in Metro Vancouver.
University of British Columbia (UBC) food microbiologist and assistant professor at the Faculty of Land and Food Systems (LFS) Kevin Allen tested 40 ready-to-eat fish samples purchased from seven large chain stores and 10 small retailers. The products included lox, smoked tuna, candied salmon and fish jerky.
Allen and his team found listeria in 20 per cent of the ready-to-eat fish products, 5 per cent of which contained had the more virulent variety of Listeria monocytogenes.
The results were recently published in the journal Food Microbiology.
He warned that even though the levels of this bacterium, Listeria monocytogenes, in the ready-to-eat fish products met federal guidelines, it can multiply during handling and storage especially quickly as it approaches the end of shelf life.
“Additional handling of ready-to-eat foods in stores, such as slicing, weighing, and packaging, may increase the potential for cross-contamination,” explained Allen. “While listeria bacteria can be killed by high heat, most people eat these fish products without further cooking.”
He noted that pregnant women, the elderly and anyone with a compromised immune system should be cognizant of the health risks of eating these products, especially since food contaminated with Listeria monocytogenes may not look or smell spoiled.
Eating foods contaminated with levels of listeria monocytogenes that exceed federal guidelines of 100 listeria cells per g can cause symptoms such as diarrhea and vomiting. Listeriosis infection can also lead to brain and blood infections and is fatal in an estimated 20-40 per cent of cases.
Allen led the study with co-authors Lili Mesak, a UBC research assistant, and Jovana Kovačevic, an LFS food science graduate student.
The researchers also tested ready-to-eat meat products from the same Metro Vancouver retailers where they bought the fish, but these products — including bologna, corned beef, cooked ham and pepperoni — did not contain listeria.
In addition, the Canadian Food Inspection Agency (CFIA) this weekend issued a statement warning the public against consuming certain refrigerated cold smoked sockeye salmon trim products because they may be contaminated with Listeria monocytogenes. The items are being sold at retailers in Vancouver.
- CFIA HEALTH HAZARD ALERT: Certain refrigerated cold smoked sockeye salmon trim products may contain Listeria monocytogenes (haccpcanada.wordpress.com)
- Cfia Health Hazard Alert Certain Milford Bay Smoked Trout Fillet May Contain Listeria Monocytogenes (haccpcanada.wordpress.com)
- Listeria warning issued for cold smoked salmon (cbc.ca)