Trichinosis, also called trichinellosis, occurs when people consume raw or undercooked pork and wild game products infected with the larvae of a species of worm called Trichinella. Once inside the host, stomach acid breaks down the cyst surrounding the larvae and worms are released into the stomach. These worms pass into the small intestine, where they mature. After mating, a mature adult female lays eggs. These eggs develop into immature worms which penetrate the walls of the small intestine and travel to muscles through the arteries. Once in the muscles, the worms curl into balls and become enclosed in a capsule (encyst). The cycle is completed when another host consumes the meat of the affected muscles and becomes infected.
Trichinosis was once very common in the United States but infection is now rare. The number of cases has decreased because of legislation prohibiting the feeding of raw-meat garbage to hogs, commercial and home freezing of pork, and the public awareness of the danger of eating raw or undercooked pork products. Cases are now less commonly associated with pork products and more often associated with eating raw or undercooked wild game meats.
Trichinosis is reportable to the Iowa Department of Public Health by Iowa Administrative Code 641 IAC 1 .