ancylostomiasis /an·cy·los·to·mi·a·sis/ (an″sĭ-los″to-mi´ah-sis) infection with hookworms; see hookworm disease, under disease.
ancylostomiasis
hookworm [hook´werm]
an·cy·lo·sto·mi·a·sis ( n s -l -st-m  -s s, ngk-l-)n. A disease caused by infestation with the hookworm Ancylostoma duodenale, characterized by gastrointestinal pain, diarrhea, and progressive anemia. Also called tunnel disease, uncinariasis. |
ancylostomiasis
[an′səlos′təmī′əsis]
hookworm disease, more specifically that caused by Ancylostoma duodenale, A. braziliense, or A. caninum. Infection by A. duodenale is generally more harmful and less responsive to treatment than that by Necator americanus, which is the hookworm most often found in the southern United States. Larvae enter the host via the skin; the adult worm lives in the intestine. The adult worms abrade the intestinal wall, eventually causing severe anemia and debilitation. Heavy infection can cause serious health complications for pregnant women, neonates, children, and the malnourished. Clinical manifestations and treatment are similar for all types of hookworms. Infection may be prevented by eliminating fecal pollution of soil and by wearing shoes. See also hookworm.
hookworm [hook´werm]
a parasitic roundworm, found mostly in the southeastern United States, that enters the human body through the skin and migrates to the intestines, where it attaches itself to the intestinal wall and sucks blood for nourishment. The hookworm most common in the United States and Central America is Necator americanus, which literally means “American killer.” It is about 1 cm (half an inch) long, with sharp hooklike teeth and a muscular gullet used in sucking blood. The female, slightly larger than the male, can lay more than 10,000 eggs a day, any one of which can hatch into a larva and invade the human body. Another common hookworm is Ancylostoma duodenale. 
Life cycle of a hookworm. From Mahon and Manuselis, 2000.
hookworm disease necatoriasis, ancylostomiasis, or infection with some other type of hookworm. Once fairly common, it is now largely confined to rural or poor areas where modern sanitation is lacking.
Larval hookworms enter the body by burrowing through the skin, usually that of the sole of the foot. The first sign of the disease may appear on the skin as small eruptions that develop into pus-filled blisters; this condition is sometimes called “ground itch.” The hookworms then enter blood vessels and are carried by the blood into the lungs. After they leave the lungs, they propel themselves up the trachea, are swallowed and washed through the stomach, and end up in the intestines. Here, if left alone, they will establish a parasitic relationship, using their host's body as a source of nourishment.
By the time they reach the intestines, about 6 weeks after they entered the body as larvae, the worms are full-grown adults. Each worm now attaches itself by hooked teeth to the intestinal wall, where it sucks its host's blood by contraction and expansion of its gullet. If large numbers of worms are present, they can cause considerable loss of blood and severe anemia. The symptoms include pallor and loss of energy; the appetite may increase. The thousands of eggs laid every day by each female worm pass out of the body in the stool, in which they can easily be seen. If the stool is not properly disposed of, the larvae that hatch from the eggs may infect other persons.
Larval hookworms enter the body by burrowing through the skin, usually that of the sole of the foot. The first sign of the disease may appear on the skin as small eruptions that develop into pus-filled blisters; this condition is sometimes called “ground itch.” The hookworms then enter blood vessels and are carried by the blood into the lungs. After they leave the lungs, they propel themselves up the trachea, are swallowed and washed through the stomach, and end up in the intestines. Here, if left alone, they will establish a parasitic relationship, using their host's body as a source of nourishment.
By the time they reach the intestines, about 6 weeks after they entered the body as larvae, the worms are full-grown adults. Each worm now attaches itself by hooked teeth to the intestinal wall, where it sucks its host's blood by contraction and expansion of its gullet. If large numbers of worms are present, they can cause considerable loss of blood and severe anemia. The symptoms include pallor and loss of energy; the appetite may increase. The thousands of eggs laid every day by each female worm pass out of the body in the stool, in which they can easily be seen. If the stool is not properly disposed of, the larvae that hatch from the eggs may infect other persons.
Treatment and Prevention. A nutritious, high-protein diet supplemented by iron is given to relieve anemia and improve health. Drug treatment is with pyrantel pamoate or mebendazole. When left untreated, hookworms can cause not only anemia but also bronchial inflammation and occasionally stunting of growth, mental retardation, and even death. Hookworm infection can be prevented by installation of sanitary toilets or, if that is not possible, by disposal of human feces in deep holes so that the soil with which the human foot comes in contact is not contaminated. Shoes should be worn outdoors to protect the feet from infection.
ancylostomiasis
infection by worms of the genus Ancylostoma or by other hookworms (Necator americanus). See also hookworm.
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