Hymenolepis

The largest genus (family Hymenolepididae) of tapeworms in the order Cyclophyllidea; especially common parasites of rodents, shrews, and aquatic birds. [G. hymen, membrane, + lepis, rind]

- H. diminuta a tapeworm species of rats and mice, rarely found in man; its cysticercoid larvae are harbored by beetles, fleas, caterpillars, and other insects.

- H. lanceolata a tapeworm of aquatic birds, rarely found in humans.

- H. nana the dwarf or dwarf mouse tapeworm; a small tapeworm of man, sometimes found in great numbers in the intestine; the cysticercoid can develop by two pathways: in the final host, with the egg from one human directly infective to another human host, in which both larval and adult stages occur, or through two hosts, an insect (or crustacean) intermediate and a vertebrate final host, the obligate two-host cycle of most cyclophylidean cestodes; in addition, H. nana can internally reinfect the same human or rodent host, producing a massive reinfection.

- H. nana, fraterna a race, strain, or subspecies of H. nana adapted to mice, although infectivity to humans may remain; the human form, H. nana, presumably is derived from the rodent strain.

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Hy·me·nol·e·pis .hī-mə-'näl-ə-pəs n a genus (the type of the family Hymenolepididae) of small taenioid tapeworms including numerous comparatively innocuous parasites of birds and mammals that usu. require insect intermediate hosts but are able in some cases (as in H. nana of humans) to complete the life cycle in a single host by means of an oncosphere which hatches in the intestine, invades a villus, and there develops into a cysticercoid which ultimately escapes and develops into an adult tapeworm in the lumen of the intestine

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n.

a genus of small widely distributed parasitic tapeworms. The dwarf tapeworm, H. nana, only 40 mm in length, lives in the human intestine. Fleas can be important vectors of this species, and children in close contact with flea-infested dogs are particularly prone to infection. H. diminuta is a common parasite of rodents; humans occasionally become infected on swallowing stored cereals contaminated with insect pests - the intermediate hosts for this parasite. Symptoms of abdominal pain, diarrhoea, loss of appetite, and headache are obvious only in heavy infections of either species. Treatment involves a course of anthelmintic.

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Hy·me·nol·e·pis (hi″mə-nolґə-pis) [Gr. hymēn membrane + lepis rind] a genus of tapeworms of the family Hymenolepididae.