Filariasis is a
mosquito borne disease. The
microfilariae sucked up by mosquito from infected man develop to infective
larvae in 10-14 days. Mosquito harbouring infective stage larvae bite
and infect a fresh host (man). Larvae migrate
Asymptomatic
microfilaraemia
This stage is characterised by the presence of microfilariae in peripheral blood during night but without any overt clinical manifestations of filariasis. It is possible that some of these have hidden lymphatic pathology in the form of dilatation at high risk of developing disease. Acute manifestations These
are characterised by recurrent attacks of fever associated with
inflammation of the lymphnodes and lymphvessels -
acute adenolymphangitis (ADL). Various
factors related to parasite like release of toxins, immune response in
infected human host , trauma
in the affected area and
secondary bacterial and / or fungal infections play a role in causing the
ADL attacks. The inflammed lymphatics of the male genitalia lead to
funiculitis or epididymoorchitis.
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Chronic manifestationsMajor chronic clinical manifestations are hydrocele, lymphoedema and elephantiasis. While hydrocele is the commonest genital manifestation in the male population, chronic epididymitis, funiculitis and lymphomatous thickening of scrotal skin can be the other genital manifestations.Lymphoedema commonly affects the lower limbs, some times the hands, and rarely the genitals and breast in females . There may be repeated attacks of ADL. Lymphoedema progresses from pitting oedema (reversible on elevation) and then non-pitting oedema followed by increase in oedema fluid volume, resulting in fibrous tissue formation, followed by skin thickening, ulceration, nodule formation and disfiguration (elephantiasis). Chyluria is prevalent in some endemic areas.
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Bilateral
vaginal
hydrocele
Grade
I
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Bilateral
vaginal hydrocele
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Hydrocele
Grade III |
Lymphoedema Grade I |
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Lymphoedema Grade |
Elephantiasis |