Hookworm
An intestinal parasite that usually causes diarrhea or cramps. Heavy infestation with hookworm can be serious for newborns, children, pregnant women, and persons who are malnourished. Hookworm infections occur mainly in tropical and subtropical climates and affect about 1 billion people — about one-fifth of the world's population. One of the most common species of hookworm, Ancylostoma duodenale, is found in southern Europe, northern Africa, northern Asia, and parts of South America. A second species, Necator americanus, was once widespread in the southeastern US early in the 20th century. Hookworms have a complex life cycle that begins and ends in the small intestine. Hookworm eggs require warm, moist, shaded soil to hatch into larvae. These barely visible larvae penetrate the skin (often through bare feet), are carried to the lungs, go through the respiratory tract to the mouth, are swallowed, and eventually reach the small intestine. This journey takes about a week. In the small intestine, the larvae develop into half-inch-long worms, attach themselves to the intestinal wall, and suck blood. The adult worms produce thousands of eggs. These eggs are passed in the feces (stool). If the eggs contaminate soil and conditions are right, they will hatch, molt, and develop into infective larvae again after 5 to 10 days. Hookworm infection is contracted from contact with soil contaminated by hookworm, by walking barefoot or accidentally swallowing contaminated soil. Children — because they play in dirt and often go barefoot — are at high risk. Since transmission of hookworm infection requires development of the larvae in soil, hookworm cannot be spread person to person. Chronic heavy hookworm infection can damage the growth and development of children. The loss of iron and protein retards growth and mental development, sometimes irreversibly. The first signs of hookworm infection are itching and a rash at the site where the larvae penetrate the skin. These signs may be followed by abdominal pain, diarrhea, loss of appetite and weight loss, and anemia. Hookworm can also cause difficulty breathing, enlargement of the heart, and irregular heartbeat. Hookworm infection have been known to be fatal, particularly in infants.
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Common name for bloodsucking nematodes of the family Ancyclostomatidae, chiefly members of the genera Ancylostoma (the Old World h.), Necator, and Uncinaria, and including the species A. caninum (dog h.) and N. americanus (New World h.).

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hook·worm 'hu̇k-.wərm n
1) any of several parasitic nematode worms of the family Ancylostomatidae that have strong buccal hooks or plates for attaching to the host's intestinal lining and that include serious bloodsucking pests
2) ANCYLOSTOMIASIS

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n.
either of two nematode worms, Necator or Ancylostoma, which live as parasites in the human intestine. Both species, also known as the New and Old World hookworms respectively, are of great medical importance (see hookworm disease).

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hook·worm (hookґwurm″) any nematode of the family Ancylostomatidae. See also hookworm disease, under disease.

Medical dictionary. 2011.

Look at other dictionaries:

  • hookworm — ► NOUN ▪ a parasitic worm which inhabits the intestines and feeds by attaching itself with hook like mouthparts …   English terms dictionary

  • hookworm — ☆ hookworm [hook′wʉrm΄ ] n. any of a superfamily (Ancylostomatoidea) of small, parasitic, intestinal nematode worms with hooks around the mouth: found esp. in tropical climates …   English World dictionary

  • Hookworm — Taxobox name = Necator americanus and Ancylostoma duodenale regnum = Animalia phylum = Nematoda classis = Secernentea ordo = Strongiloidae familia = Ancylostomatidae genus = Necator/Ancylostoma subdivision ranks = Species subdivision = Species N …   Wikipedia

  • hookworm — UK [ˈhʊkˌwɜː(r)m] / US [ˈhʊkˌwɜrm] noun Word forms hookworm : singular hookworm plural hookworms 1) [countable] a long thin creature that lives in the intestines of humans and other animals, and that can cause disease 2) [uncountable] the disease …   English dictionary

  • hookworm — hookwormy, adj. /hook werrm /, n. 1. any of certain bloodsucking nematode worms, as Ancylostoma duodenale and Necator americanus, parasitic in the intestine of humans and other animals. 2. Also called hookworm disease. a disease caused by… …   Universalium

  • hookworm — n. either of two nematode worms, Necator americanus or Ancylostoma duodenale, which live as parasites in the human intestine. Both species, also known as the New and Old World hookworms respectively, are of great medical importance (see hookworm… …   The new mediacal dictionary

  • hookworm — /ˈhʊkwɜm / (say hookwerm) noun 1. any of certain bloodsucking nematode worms, as Ancylostoma duodenale and Necator americanus, parasitic in the intestine of humans and other animals. 2. → hookworm disease …   Australian English dictionary

  • hookworm — noun Date: 1902 1. any of several parasitic nematode worms (family Ancylostomatidae) that have strong buccal hooks or plates for attaching to the host s intestinal lining and that include serious bloodsucking pests 2. infestation with or disease… …   New Collegiate Dictionary

  • hookworm — noun Any of various parasitic bloodsucking roundworms which cause disease, especially the species Ancylostoma duodenale and Necator americanus. They have hooked mouthparts and enter their hosts by boring through the skin …   Wiktionary

  • hookworm — Synonyms and related words: African lethargy, Asiatic cholera, Chagres fever, German measles, Haverhill fever, acute articular rheumatism, ague, alkali disease, amebiasis, amebic dysentery, anthrax, bacillary dysentery, bastard measles, black… …   Moby Thesaurus

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