Light micrograph of Trichinella spiralis, a parasitic roundworm that causes trichinosis. The life cycle of the parasite begins when the infectious cysts are eaten with the flesh of a meat-eating animal. Trichinosis begins with the colonization of trichinella larvae in muscles where they grow. Migrating juveniles cause pain as they invade muscle tissue. Symptoms may include swelling, delirium, cardiac and pulmonary difficulty, pneumonia, nervous disorders, deafness and delayed or lost reflexes. Nausea, dysentery, and colic are symptoms of adult worms. Magnification 64x @ 35mm.