Eating raw or undercooked meats, especially pork, but also bear, fox, dog, wolf, horse, seal, or walrus, can put you at risk for trichinosis. Trichinosis is caused by eating meat infected with the larvae of a species of worm called Trichinella. Infection is most common in areas where raw or undercooked pork, such as ham or sausage, is eaten.
The first symptoms of trichinosis include nausea, diarrhea, vomiting, fatigue, fever, and abdominal discomfort, followed by headaches, fevers, chills, cough, eye swelling, aching joints and muscle pains, itchy skin, diarrhea, or constipation. In severe cases, death can occur.
When a person or animal eats meat that contains Trichinella cysts, the acid in the stomach dissolves the hard covering of the cyst and releases the worms. The worms pass into the small intestine and mature in a couple of days. After mating, adult females lay eggs, which develop into immature worms. They travel through the circulatory system to the muscles where they become enclosed in a capsule again.
Prevention requires that meat products be cooked until the juices run clear or to an internal temperature of 180° F. Pork should be frozen for 20 days to kill any worms. The worms in game meats may not effectively be killed by freezing.
Several safe and effective prescription drugs are available to treat trichinosis.
Curing (salting), drying, smoking, or microwaving meat does not consistently kill infectious worms.