Elephantiasis
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| Elephantiasis-causes |
The filarial nematodes belongs to the order Filaroidea. They are lipless and filiform worms in which pharynx is not bulbous, but muscular anteriorly and galndular posteriorly. Genital aperture in female in present in the pharyngeal region, and males are non- bursate. Following description belongs to WUCHERERIA (FAILARIA) Bancroft , the human filarial worm causing filariasis or elephantiasis.
Systematic Position
Phylum. Nematoda
Class. Phasmidia
Order. Filaroidea
Family. Filariidac
Genus. Wuchereria
Species. Bancrofti
Geographic Distribution
Wuchereria bancrofti has a widespread distribution throughout world except polar regions. It is found in Arabia, India, Malaya, China, Korea, Japan, East Indies, Brazil and , South Pacific Islands. It is realively absent from Europe, North America and Africa.
Habit and Habitat
Filarial worm isa dreaded human parasite of human blood and lymph. It is a digenetic parasite completing its life cycle in two hosts. Final host is man harbouring the adult worms, while intermediate host is a blood - sucking insect, usually a mosquito. Adult worm live coiled up in the lymph glands and lymph passages of the man, where they often the flow of lymph.
Morphology
Adult worms are filiform and cylindrical in shape and both body wands terminate bluntly. They are coloured creamy white . Sexes are separated and there is a distinct secual dimorphism. Female measures 65 to 40mm and 0.25mm in diameter, while male 40mm and 0.1mm respectively. Mouth aperture is simply, without anterior muscular portion and a posterior glandular portion. An oesophageal bulb is lacking. Intestine is simple, as in other nematodes. Posterior end of male is sharply curved ventrally, containing a number of genital, papillae, caudal alae and two unequal copulatory spicules, Vulva or genital pore or female is located ventrally in the pharyngeal region, and provided, with pyriform ejector mechanism or ovijector.
