filariasis

Presence of filariae in the tissues of the body or in blood (microfilaremia) or tissue fluids (microfilariasis), occurring in tropical and subtropical regions; living worms cause minimal tissue reaction, which may be asymptomatic, but death of the adult worms leads to granulomatous inflammation and permanent fibrosis causing obstruction of the lymphatic channels from dense hyalinized scars in the subcutaneous tissues; the most serious consequence is elephantiasis or pachyderma.

- bancroftian f. f. caused by Wuchereria bancrofti.

- Brug f. infection with filarial organism Brugia malayi, which causes adenitis, fever, lymphangitis, and sometimes elephantiasis; occurs primarily in southeast Asia, India, Indonesia, China, Japan, Korea, and the Philippines.

- periodic f. a form of f. in which microfilariae appear in the peripheral blood at regular 24-hr intervals; usually refers to the nocturnal periodicity of bancroftian f..

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fil·a·ri·a·sis also fil·a·ri·o·sis .fil-ə-'rī-ə-səs n, pl -a·ses also -o·ses -.sēz infestation with or disease caused by filariae

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n.

a disease, common in the tropics and subtropics, caused by the presence in the lymph vessels of the parasitic nematode worms Wuchereria bancrofti and Brugia malayi (see filaria). The worms, which are transmitted to humans by various mosquitoes (including Aëdes, Culex, Anopheles, and Mansonia), bring about inflammation and eventual blocking of lymph vessels, which causes the surrounding tissues to swell (see elephantiasis). The rupture of urinary lymphatics may lead to the presence of chyle in the urine. Filariasis is treated with the drug diethylcarbamazine.

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fil·a·ri·a·sis (fil″ə-riґə-sis) infestation by filariae.