TRICHINOSIS

also called Trichiniasis, a disorder resulting from infestation with the small roundworm Trichinella spiralis, commonly acquired by humans by the eating of undercooked pork containing encapsulated larvae of the parasite. In the stomach and small intestine, the capsular coating is digested, and the liberated larvae invade the mucosal lining of the small intestine, becoming adults within a week. After fertilization the female worm deposits larvae into the mucosa and, sometimes, directly into the lymphatics, from which the larvae reach the blood and are carried to all parts of the body, notably the burrows of skeletal muscles, where they reach the encapsulating stage. The muscles most often invaded are those of the diaphragm, eyes, neck, throat, larynx, and tongue. In the muscles, the larval capsules, or cysts, may remain alive for years, eventually becoming calcified. Trichinosis is more common in Europe and the United States than in other parts of the world. In the United States the incidence of infection (as detected by finding calcified cysts at autopsy) may be as high as 15 to 20 percent. Only a small percentage of infected persons, however, have sufficient parasites to produce recognizable clinical symptoms, which include diarrhea, nausea, vomiting, and fever in the early stage, followed later by pain, stiffness, and swelling of various muscular structures, and often edema (swelling) of the face. Treatment consists of the use of anti-inflammatory drugs for symptomatic relief; thiabendazole has been reported to be highly effective in destroying the parasites in the digestive tract. There is no practical method for the large-scale detection of trichinous pork, and the surest safeguard remains the thorough cooking of pork.