Trichiniasis Patient Information Fact Sheet

What is trichiniasis?
Trichiniasis is a disease caused by an intestinal worm whose larvae migrate to and become encapsulated in the muscles. Symptoms in humans vary and depend on the number of larvae ingested (some will not experience any symptoms at all). Early signs may include muscle soreness, diarrhea, vomiting, swelling of the eyelids and fever. For mild to moderate infections, most symptoms subside within a few weeks although fatigue, weakness, and diarrhea may last for months. In the most serious cases, heart and neurological complications can occur which may result in death.

How do you contract trichiniasis?
By eating raw or undercooked pork and wild game products infected with the larvae of a species of worm called Trichinella. When a human or animal eats meat that contains infective Trichinella cysts, the acid in the stomach dissolves the hard covering of the cyst and releases the worms. The worms mature, mate and lay eggs. Eggs develop into immature worms and travel to the muscles. Within the muscles, the worms curl into a ball and become enclosed in a capsule (cyst). Infection occurs worldwide, but is most common in areas where raw or undercooked pork, such as ham or sausage, is eaten.

The time between eating the contaminated meat and symptoms of infection developing often depends on the number of parasites ingested. Diarrhea and vomiting may occur within a few days. Other symptoms usually appear after 2–8 weeks.

Diagnosis can be made by blood test or by taking a small sample of muscle tissue (biopsy).

How is trichiniasis treated and prevented?
The drug mebendazole (Vermox) is effective in the treatment of this disorder. To prevent contracting trichiniasis, cook all pork and meat from wild animals thoroughly.

Further information
Centers for Disease Control and Prevention: http://www.cdc.gov/parasites/trichinellosis/

Last Reviewed: June 2013