Wuchereria bancrofti ·

Has a spotty world-wide distribution throughout the tropics and subtropics, Africa, Asia, and S. America.

·      Microfilaria prefers climate with humidity and heat.

·      More than 400million people are at risk

o   8  million are infected

v Habitat

o   Adults: - coiled in lymphatic glands,lying in lymphatic vessels,

o   Microfilariae-

§   in lymphatic vessels,in the peripheral blood (at night),in the lung and other internal organs (at day)

§  Infective larvae; - In the gut and muscles & mouth parts of certain species of mosquitoes of the genus (Culex, Aedes, Anopheles).      

v Morphology

o   Male- Tapered and round swollen head and Sharply curved tail with two unequal spicules

                                                                                                                                                                          

o   Female- longer than male

                          - Curved tail tapered front end and vulva at a cervical area.

¨    Microfilariae (275-300µm)

·        Has a sheath which stain –pink with Giemsa and Pale with heamatoxylin stain

·        Body nuclei- are fewer and more distinct than other species and with no nuclei at the end of the pointed tail.

·        Body curves are smooth and few with smooth cuticle and bluntly rounded anteriorly and pointed caudally                                 

v Pathology & clinical features

·        Causes lymphatic(bancroftian ) filariasis  or elephantiasis

·        Affected organs – limbs, genital organs, and breasts

·        Pathology of the parasite is due to adult worms due to immunopathogensis

Ø  As the worms dies host immune reactions continues - a fibro-proliferative granuloma obstructs the lymphatic vessels -swelling & fibrosis - lymphedema  -  bacterial infection          =Elephantiasis.

v Major symptoms:

·        Recurrent attacks of fever, and Painful inflamed lymphatics,

·        Enlarged lymph nodes = swollen lower extremities,  rarely genital organs, and breasts

·        Stretched skin is susceptible to traumatic injury and bacterial infections.

                           = Elephantiasis, enlargement of the lower limb

v Laboratory diagnosis

Ø  Specimens- blood, urine, aspirates and Sample collection depends on the periodicity of species

v Method: Microscopy

·        Wet or stained blood films

·        Immunological (antigen) detection.

v Prevention & control

·        Controlling mosquitoes vector,

·        Avoid mosquitoes bite,

·        Treatment & health education