Trichina (tri-ki'nah)

Syn.: Trichinella. A genus of parasitic worms of the Nemathelminthes, order Nematoda, and family Trichinellidae. T. contort a. Syn.: Anguillulina putrefaciens. A small nematode which may cause gastric irritation and vomiting. T. cystic us. See Filaria Bancrofti under Filaria. T. spiral is. A small viviparous species from V20 to Vis of an inch in length (the female being somewhat the larger), having a pointed, narrow, and unarmed head with a small oral aperture. The larvae are very tenacious of life, having been kept alive for a month. They present the form of spirally coiled worms, in the interior of small globular or oval cysts, about Vso of an inch long, and are usually found in the voluntary muscles. In some cases they are found free. The flesh containing the larvae having been eaten, they are set free during digestion and attain maturity rapidly, sometimes within forty-eight hours, and after a week the young, piercing the intestines, burrow into the ti ues, producing trichiniasis. The T. is a parasite of the black rat and the sewer rat and the disease spreads to dogs, cats, and pigs. Human beings become infected by eating insufficiently cooked pork or smoked ham. [Gr., thrix, a hair.]