释义 |
DictionarySeeloaEncyclopediaSeeLoaLoa loa
Loa [lo´ah] a genus of filarial nematodes.Loa lo´a a threadlike species found in West Africa, 2–5 cm (1–2 in) long, that inhabits the subcutaneous connective tissue of the body, which it traverses freely (see loiasis). It is seen especially about the orbit, including under the conjunctiva, causing itching and occasionally edematous swellings. The immature forms, or microfilariae, are diurnal, being found in the peripheral circulation in greatest concentrations during the day. Flies of the genus Chrysops are the intermediate hosts and vectors.Loa loa (lō'ă lō'ă), The African eye worm, a species of the family Onchocercidae (superfamily Filarioidea) that is indigenous to the western part of equatorial Africa, especially in the region of the Congo River, and is the causal agent of loiasis. Adult worms are white or gray-white, cylindric, and threadlike, the males averaging 25-35 × 0.3-0.4 mm (with a curved tail) and the females ranging from 50-60 × 0.4-0.6 mm; microfilariae are ensheathed, with nuclei extending to the tip of the tail. The life cycle is somewhat similar to that of Wuchereria species; humans are the only known definitive host, and parasites are transmitted by Chrysops flies (family Tabanidae); infective larvae from the latter require 3 years or more to mature in humans, and the adult forms may persist in a human host for as long as 17 years. See also: loiasis. Lo·a lo·a (lō'ă lō'ă) The African eye worm, a species of the family Onchocercidae that is the causal agent of loiasis. Humans are the only known definitive host, and parasites are transmitted by Chrysops flies; infective larvae from the latter require at least 3 years to mature in humans, and the adult forms may persist in humans for as long as 17 years. See also: loiasis LOA LOA IN BLOOD: (Orig. mag. ×400) LOA LOA IN BLOODLoa loa (lō′ă) [W. African] The African eyeworm, a species of filarial worm that infests the subcutaneous tissues and conjunctiva of humans. Its migration causes itching and a creeping sensation. Sometimes it causes itchy edematous areas known as Calabar swellings. It is transmitted by flies of the genus Chrysops. See: illustrationillustrationLoa loa A filarial worm, known as the African eye worm. 2.5–6 cm long the worms are acquired by the bite of the Chrysops fly and may live in the tissues under the skin for over 15 years, causing Calabar swellings. Occasionally a worm can be observed passing across the white of the eye under the CONJUNCTIVA. See also LOIASIS. |