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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.
hookworm/hook·worm/ (hook´werm) a nematode parasitic in the intestines of humans and other vertebrates; two important species are Necator americanus (American, or New World, h.) and Ancylostoma duodenale (Old World h.). Infection may cause serious illness; see under disease, and see ground itch, under itch.
hookwormParasitology A hematophagous nematode of family Ancylostomatidiae–eg, Old World hookworm–Ancylostoma duodenale and New World hookworm–Necator americanus that sensitizes the penetration site–eg, skin, causing 'ground itch', or lungs–eg, Loeffler syndrome as the worms wiggle through, causing eosinophilia and, due to bloodsucking, anemia Lab Rhabditidiform larvae may be confused with Strongyloides stercoralis; eggs may be confused with Trichostrongylus and Meloidogyne spp. See Ancylostoma duodenale, Necator americanus.
Hookworm eggs deposited on the soil in feces mature into larvae capable of penetrating the skin, esp. the bare skin of the foot. An allergic or inflamed rash may develop at the entry site. The larvae pass from the skin into the venous circulation and travel to the alveolar capillaries of the lungs, up the bronchi and trachea and into the gastrointestinal tract. There they mature, attach to the mucous membrane of the intestine, and begin feeding on host blood. The adults secrete an anticoagulant, which promotes additional bleeding. Eventually, the host develops iron-deficiency anemia. Patients sometimes report nausea, colicky abdominal pain, bloating, and pica. Affected children may suffer growth retardation. The adult worms produce eggs that are excreted in the feces, perpetuating the cycle of infection. The detection of these eggs in the stool provides the basis for diagnosis of the disease.
Mebendazole and pyrantel pamoate are used to eradicate the infection. Iron supplements are needed to treat the anemia.