Trichina

Trichina, parasitic roundworm, belonging to the trichina family, that causes an infection known as trichinosis. Larval worms that infect the muscles of animals usually die by themselves; if an infected animal is eaten, however, the larvae can be set free from their cysts (sacs) to invade the intestine of the host and reproduce more larvae. The degree of infection in these cases ranges from mild to fatal. Preventative measures include sufficient cooking and freezing of meat.