What is trichinosis?

Trichinosis is an infection caused by parasitic worms called Trichinella. In infected animals, Trichinella can be found in muscle or organ tissues, within a small, soft shell called a cyst. The cysts are common in animals such as rats, pigs (including wild/feral pigs), and bears, and have been found in a wide range of wild carnivores and omnivores. Animals in North America, the Arctic, Africa, and perhaps worldwide may be found to harbour Trichinella cysts.

How is trichinosis spread?

Trichinosis is spread by eating Trichinella cysts in raw or undercooked meat. The worms “hatch” from the cysts in the stomach and multiply. New Trichinella worms move through the bloodstream into the body, usually muscles, to make cysts in the new host.  Trichinosis is not spread from one person to another.

What are the symptoms of trichinosis?

Symptoms during the first week after eating cysts may include:

  • abdominal pain
  • nausea and vomiting
  • diarrhea

Additional symptoms 5 to 45 days (often 8 to 15 days) after eating cysts may include:

  • fever
  • muscle pain
  • swelling around the eyes or of the face
  • hive-like rash
  • blood appearing under the fingernails and in the whites of the eyes

Symptoms of trichinosis can be severe or even fatal involving the heart, nervous system, or lungs, especially if the number of worms that enter the body is high. The cysts gradually die as symptoms resolve.

Is there a treatment for trichinosis?

Yes, effective treatment for trichinosis can be prescribed by a healthcare provider. If there are no symptoms, no treatment may be required. If you are concerned you may have trichinosis, speak with your healthcare provider.

Are there any restrictions or special considerations for people ill with trichinosis?

There are no restrictions for people ill with trichinosis.

Any time you have diarrhea or vomiting, do the following until 24 hours after the diarrhea or vomiting stops:

  • Wash hands often, especially after using the toilet.
  • Stay home from work/school/child care.
  • Do not prepare food for others.
  • Do not use swimming pools/hot tubs.
How can I protect myself against trichinosis?

To prevent becoming ill:

  • Always wash hands well with soap and water for at least 15 seconds before and after preparing food, before eating, after using the toilet, after changing diapers, after handling pets or their feces, and anytime hands may be dirty.
  • Buy inspected meat to minimize the risk of cysts.
  • Fully cook all pork and wild/feral animal meat to a minimum internal temperature of 71°C/160°F prior to eating.
  • Use a probe thermometer to check the final internal temperature.
  • Always wash your hands after handling raw meats.
  • Clean counters where food is prepared with warm soapy water, and sanitize utensils, cutting boards and surfaces that may have been contaminated with raw meat.
  • Never taste or sample raw meat during food preparation, such as during sausage making.
What is Ottawa Public Health's role?

Ottawa Public Health (OPH) must be notified by healthcare providers and laboratories when a person is found to have trichinosis. OPH follows up with the person’s healthcare provider and conducts an investigation to potentially determine the cause or source of illness and to provide education to the person and to other persons who may have eaten the same foods. Also, public health inspectors visit grocery stores, butchers and restaurants to ensure that only inspected meat is sold to the public. Some wild animal meat can be served at special events called “wild game dinners”; however, the hosts of these events must contact OPH in advance, and notify attendees that the meat has not been inspected.

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