During the stage of infection, after the immature trichina worms are freed from their cysts, the maturing larvae cause severe irritation of the intestinal tract. Symptoms of infection include abdominal pain, nausea, vomiting, and watery stools. With the release, or migration, of the larvae into the bloodstream, the face very often becomes puffy and swollen, especially around the eyes, and headache and even delirium occur; the heart muscles also are often damaged. The invasion stage is marked by muscle spasms and pains in the joints... (Read More)