Disease Fact Sheet Series:

What is trichinosis?
Trichinosis is a foodborne disease caused by a tiny parasitic worm, Trichinella spiralis.

Who gets trichinosis?
Anyone who eats undercooked meat of infected animals can develop trichinosis. Pork products are implicated more often than other meats.

How is trichinosis spread?
Animals such as pigs, cats, rats and many wild animals including fox, wolf, boar and bear harbor the parasite in their muscle tissue. The worm is spread when infected animal flesh is ingested by other animals. When humans eat infected pig meat that has been improperly cooked, they become infected. Improperly cooked wild animal meat may also be responsible for infecting humans. Person-to person spread does not occur.

What are the symptoms of trichinosis?
The symptoms usually start with abdominal pain and diarrhea followed by fever, muscle soreness, pain and swelling around the eyes. Thirst, profuse sweating, chills, weakness and tiredness may develop. Chest pain may be experienced since the parasite may become imbedded in the diaphragm (the thin muscle separating the lungs from abdominal organs).

How soon after infection do symptoms appear?
The period between consuming the parasite and the beginning of symptoms varies depending upon the number of parasites in the meat and the amount eaten. It can range from 5 to 45 days but is usually 10 to 14 days.

Does past infection with trichinosis make a person immune?
Partial immunity may develop from infection.

What is the treatment for trichinosis?
A drug called mebendazole is used in treatment.

What can be the effect if not being treated for trichinosis?
Failure to treat could be fatal.

What can be done to prevent the spread of trichinosis?
The best prevention is to make sure that pork and wild game meat products are properly cooked. The desirable internal temperature is at least 150 degrees F. Storing infected meat in a freezer with a temperature of -13 degrees F or lower for 10 days will also destroy the parasite. Utensils used for processing pork and wild game meat should be thoroughly cleaned before using them for other meats.

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Last Revised: November 04, 2008