Risky eating

Food-borne illnesses affect up to 13 million Canadians, or more than 40 per cent of the population, each year according to public health experts.

After months of bad news from E-coli tainted spinach to pet food contaminated with a toxic chemical, food safety is once again in the headlines with the recent deadly outbreak of Listeriosis, a serious infection caused by eating food contaminated with the bacterium Listeria monocytogenes (commonly known as Listeria).

Listeriosis can cause brain infection and even death. At the time of publication, a total of 11 deaths have been reported in Canada’s most recent outbreak, although because of the disease’s long incubation period this number is expected to rise.

The deaths are among dozens of confirmed cases of Listeriosis that are linked to the outbreak blamed on sandwich meats from the Maple Leaf Foods processing plant in Toronto.

About Listeria

Listeria is a bacterium that is found in soil, vegetation, water, sewage and the feces of animals and humans.

Symptoms of an infection are often more severe than other forms of food poisoning and can include nausea, vomiting, cramps, diarrhea, headache, constipation, persistent fever. If it spreads to the nervous system, symptoms may also include severe headache, stiff neck, confusion, loss of balance, and convulsions. After eating contaminated food, symptoms usually appear within two to 30 days, but can take as long as 90 days.

Listeria is more likely to cause death than other bacteria that cause food poisoning. In fact, 20 to 30 per cent of food-borne Listeriosis infections in high-risk individuals may be fatal, according to Health Canada

The disease affects primarily persons of advanced age, pregnant women, newborns, and adults with weakened immune systems, such as chemotherapy or organ transplant patients.

Minimizing the risk

Reduce your risk of contracting Listeriosis (as well as other food-borne illnesses) by following these 10 steps.*

– Read and follow all package labels and instructions on food preparation and storage.

– After handling foods, especially raw foods such as meat and fish, thoroughly clean and sanitize all surfaces used for food preparation with a kitchen sanitizer or a bleach solution (5 ml household bleach to 750 ml of water), and rinse with water.

– To avoid cross-contamination, clean all knives, cutting boards and utensils used with raw food before using them again.

– Thoroughly clean fruits and vegetables before you eat them.

– Refrigerate or freeze perishable food, prepared food and leftovers within two hours.

– Defrost food in the refrigerator, in cold water or in the microwave, but never at room temperature.

– Keep leftovers for a maximum of four days only and reheat them to an internal temperature of 74°C (165°F) before eating them.

– Check the temperature in your refrigerator using a thermometer to make sure it is at 4°C (40°F) or below. As the storage temperature increases, so does the growth of Listeria in foods.

– Frequently wash and disinfect the refrigerator. This will make it less likely for Listeria to be transferred from contaminated food and surfaces to non-contaminated foods.

*Health Canada

Unlike most bacteria, Listeria can survive and grow on foods being stored in the refrigerator – but it can be killed off by using proper cooking techniques. Note: foods that are contaminated with Listeria look, smell and taste normal.

High risk individuals should also avoid certain foods such as hot dogs, especially straight from the package without further heating. (The fluid in hot dog packages may contain more Listeria than the hot dogs.) Never under any circumstance should hot dogs be eaten straight from the package, but instead cooked until steaming hot.

Non-dried deli meats and blue-veined cheeses if they are made from unpasteurized milk should also be avoided by people at high risk of Listeriosis. (See the complete list of foods to avoid.)

If you have fear you may have eaten a contaminated product and do not have any symptoms, no tests are required, according to Health Canada. However, if you become ill with fever or serious illness, contact your health care provider and mention your possible exposure. (See Canadian Food Inspection Agency (CFIA) for most current list of food recalls.)


For more information on Listeria go to the Canadian Food Inspection Agency fact sheet, Food Safety Facts on Listeria.

Sources: Health Canada, Canadian Food Inspection Agency, U.S. Centers for Disease Control, Mayo Clinic.


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