Listeria (Listeria monocytogenes) is a type of bacterium often found in food, in soil, water and sewage. Many animals and people can carry the bacteria and not know it. and elsewhere in nature. It can cause a rare but serious disease called Listeriosis, a very rare disease that can sicken or potentially kill high-risk individuals including the elderly or infirm.
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Cause
Food contaminated with Listeria can be killed by proper cooking. However, Listeria can live and sometimes grow on foods, such as deli meats, being stored in the refrigerator. What troubles consumers is that food contaminated with Listeria looks, smells and tastes normal.
Listeria is more likely to cause sickness and death than many other bacteria that cause food poisoning (20 30% of food-related Listeriosis infections in high-risk individuals can cause death). High risk patients included:
Pregnant mothers
Elderly
People with weakened immune systems
Symptoms
Most people who contract Listeria wont know they have it. High-risk individuals however may demonstrate food-poisoning like symptoms including:
Nausea
Vomiting
Diarrhea
Severe Headache
Cramps
Constipation
Persistent fever
Mild Listeriosis usually begins about one day after eating heavily contaminated food. For the more serious form of Listeriosis, the incubation period is up to 90 days after exposure.
Prevention
Health Canada recommends the following to avoid or minimize the risk of Listeriosis:
Read and follow all package labels and instructions on food preparation and storage.
After handling foods in the kitchen, especially raw foods such as meat and fish, thoroughly clean and sanitize all surfaces used for food preparation with a kitchen sanitizer (following the directions on the container) or use 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 74C (165F) before eating them.
Check the temperature in your refrigerator using a thermometer to make sure it is at 4C (40F) or below. As the storage temperature increases, so does the growth of Listeria in foods. The higher the number of bacteria in foods, the greater is the risk of getting sick.
Frequently wash and disinfect the refrigerator. The more often it is cleaned, the less chance there will be for Listeria to be transferred from contaminated food and surfaces to non-contaminated foods.
In addition, Health Canada recommends the following for high-risk individuals:
Avoid hot dogs or reheat until steaming hot (ensure that all liquid from the packaging is properly disposed)
Avoid non-heated deli meats
Avoid soft and semi-soft cheeses such as feta, Brie, Camembert and blue-veined cheese
Avoid raw or under-cooked meat, fish and chicken
Refrigerate pate and meat spreads
Refrigerate smoked seafood and seafood spreads
For more information, visit the Health Canada website and read Listeria and Food Safety.
