Government of Canada
Symbol of the Government of Canada

Pathogen: Listeria monocytogenes - bacteria

PDF (468 kb)


Symptoms

  • Persisting fever
  • Muscle aches
  • Constipation
  • Nausea (sometimes)
  • Vomiting (sometimes)
  • If infection spreads to the nervous system:
    • Headache
    • Stiff neck
    • Confusion
    • Loss of balance

Start of symptoms / how long they last

  • Symptoms usually start within 3 to 70 days after exposure to the bacteria.
  • How long the illness lasts can vary depending on the severity of illness.

How you can get sick

  • By eating or drinking food or beverages contaminated with Listeria monocytogenes
  • Through cross-contamination during food preparation in the kitchen or in the processing plant

Potential health impacts

  • The disease mainly affects adults 60 years and older, pregnant women, newborns, and people with weakened immune systems.
  • Pregnant women infected with this bacteria can experience a mild, flu-like illness however infections during pregnancy can lead to miscarriage, stillbirth, premature delivery, or infection of the newborn baby.
  • Infection with Listeria may be followed by meningitis encephalitis (an infection of the brain or its surrounding tissues) and/or septicaemia (bloodstream infection), either of which can cause death.

Food commonly associated

  • Deli meats (cold cuts or "ready-to-eat" meat
  • Hot dogs
  • Raw cheeses from unpasteurized milk, including soft and semi-soft cheese, such as Brie, Camembert and blue-veined cheese
  • Raw food, such as uncooked or undercooked meats
  • Refrigerated pâtés and meat spreads
  • Refrigerated smoked seafood

How to protect yourself

  • Use a digital food thermometer to check the internal temperature of your food. Refer to the chart on page 5.
  • Wash your hands after handling meat products.
  • Adults 60 years and older, pregnant women, and people with weakened immune systems should avoid food commonly associated with Listeria, including hot dogs, deli meats and unpasteurized dairy products. If you still choose to eat this food, follow these safe food handling practices:
    • Cook high-risk food, including unpasteurized dairy products, deli meat, hot dogs, meat and poultry, to a safe internal temperature. Refer to the chart on page 5.
    • Avoid spreading fluid from hot dog and deli meat packages onto other food, cutting boards, utensils, dishes and food preparation surfaces.
    • Eat only pasteurized cheese, including hard cheese, such as Colby, Cheddar, Swiss and Parmesan Cheese.

Click on image for larger view
Listeria monocytogenes Listeria monocytogenes