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Thelaziasis
Thelaziasis (occasionally spelled "thelaziosis") is the term for infestation with parasitic nematodes of the genus ''Thelazia''. The adults of all ''Thelazia'' species discovered so far inhabit the eyes and associated tissues (such as eyelids, tear ducts, etc.) of various mammal and bird hosts, including humans. Thelazia nematodes are often referred to as "eyeworms." ==General life cycle== In the uterus of the adult female, the embryos develop into first-stage larvae (L1), which remain in the eggshell (sheath). The female deposits these sheathed larvae in the tears of the mammal or bird definitive host, and the larvae are ingested by tear-feeding flies. In the fly, the larvae "hatch" (exsheath), penetrate the gut wall, and migrate to either the fat body, testes or egg follicles (depending on the species). There they develop into third-stage larvae (L3), which migrate to the head of the fly. The infective L3 larvae wiggle out of the straw-like feeding apparatus of the fly when it feeds on the tears of another mammal or bird host. The L3 larvae develop into adults in the eye or surrounding tissues of the host, where they may live for over one year. In the definitive host, ''Thelazia'' have been found in various tissues of the orbit (or socket) of the eye, including within the eyelids, in the tear glands, tear ducts, or the so-called "third eyelid" (nictitating membrane) or in the eyeball itself.
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Thelaziasis」の詳細全文を読む
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