Trichinosis, also called
trichinellosis, or
trichiniasis, is a
parasitic disease caused by eating raw or undercooked
pork or
wild game infected with the
larvae of a species of
roundworm Trichinella spiralis, commonly called the
trichina worm.
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Between 2002 and 2007, 11 cases were reported to CDC each year on average in the United States;
[2] these were mostly the result of eating undercooked game, bear meat, or home-reared pigs. It is common in developing countries where meat fed to pigs is raw or undercooked, but many cases also come from developed countries in Europe and North America, where raw or undercooked pork and wild game may be consumed as delicacies.
[3]
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The typical life cycle for
T. spiralis involves humans, pigs, and rodents. Pigs become infected when they eat infectious cysts in raw meat, often pork or rats (
sylvatic cycle). Humans become infected when they eat raw or undercooked infected pork (
domestic cycle). After humans ingest the
cysts from infected undercooked meat, pepsin and hydrochloric acid help free the larvae in the cysts in the stomach.
[10] The larvae then migrate to the small intestine, where they molt four times before becoming adults.
[10]
Thirty to 34 hours after the cysts were originally ingested, the adults mate, and within five days produce larvae.
[10] The worms can only reproduce for a limited time because the immune system will eventually expel them from the small intestine.
[10] The larvae then use their piercing mouthpart, called the "stylet", to pass through the intestinal mucosa and enter the lymphatic vessels, and then enter the bloodstream.
[7]
http://en.wikipedia.org/wiki/Trichinosis