What is Trichinosis?

Trichinosis is an infection caused by eating raw or undercooked meat from pork or wild game animals which are infected with the larvae of parasite called Trichinella spiradis.

Who gets Trichinosis?

Anyone who eats undercooked meat of infected animals can develop trichinosis. Raw or undercooked pork, such has ham or sausage, is the most frequent source. Improperly cooked wild animal meat, such as bear, may also be responsible for infecting humans.

What are the symptoms of Trichinosis?

The first symptoms of infection can be abdominal discomfort, diarrhea, nausea, vomiting and fever. Eye swelling, muscle pains, weakness, and prostration may follow later. Symptoms may range from very mild to severe, depending upon the number of infectious worms consumed in meat.

How soon do the symptoms occur?

Abdominal symptoms of Trichinosis can occur one to two days after infection. Further symptoms usually follow 8 to 15 days after eating infected meat. The incubation period varies depending upon the number of parasites in the meat and the amount eaten.

How is Trichinosis diagnosed?

A blood test or muscle biopsy can show if you have trichinosis.

What is the treatment for Trichinosis?

Several safe and effective drugs are available to treat Trichinosis. Treatment should begin as soon as possible. The decision to treat is based upon the symptoms, exposure to the infected meat and laboratory tests.

How is Trichinosis spread?

The Trichinella parasite is spread between meat-eating animals such pigs, rats, dogs and many wild animals, including foxes, wolves, wild boars and bears. When an animal eats meat containing Trichinella cysts, the larval worms within those cysts are released in the stomach and travel to the intestine where they mature. The adult female worms produce larvae which enter the blood stream and are disseminated throughout the body where they become encapsulated (form cysts) in the muscles. That muscle tissue (or meat) can then become a source of infection for other meat-eating animals. Humans become infected through eating raw or undercooked Trichinella contaminated pork or game animal meat.

How can Trichinosis be prevented?

The best prevention is properly cooking all meat. The internal temperature of properly cooked meat should reach at least 170 F during cooking. Freezing pork for 10 days at -13 F will also destroy the parasite. Freezing is not reliably effective for wild animal meats. Curing, drying, smoking or microwaving meat does not consistently kill infective worms.

More about Trichinosis

• Surveillance Case Definitions