ascariasis /as′kərī″əsis/ [Gk, askaris, intestinal worm, osis, condition] , the most common parasitic infection in the world, caused by a parasitic worm, Ascaris lumbricoides, that migrates through the lungs in its larval stage. The eggs are passed in human feces, contaminating the soil and allowing transmission to the mouths of others through hands, water, or food. After hatching in the small intestine, the larvae travel through the wall of the intestine and are carried by the lymphatics and blood to the lungs. The larvae are swallowed; they mature in the jejunum, where they release eggs; and the cycle is repeated. ▪ OBSERVATIONS: Some individuals have no symptoms. Heavy intestinal infection may result in abdominal cramps and obstruction. In children infection may cause stunted growth. Early respiratory symptoms of coughing, wheezing, hemoptysis, and fever are caused by the migration of worms through the respiratory tract. The infective eggs are readily identified in the feces. ▪ INTERVENTIONS: Piperazine citrate, pyrantel pamoate, mebendazole, and albendazole are effective treatments. ▪ PATIENT CARE CONSIDERATIONS: The disease can be prevented by educating people, especially children, about good hygiene, such as handwashing, especially before preparing food. Washing fruits and vegetables before consumption is also important.
