Adult stage of filarial worms responsible for diseases in all of the following except:

Ans: B. Onchocerca volvulus Adult stage of Onchocerca volvulus filarial worms does not cause any illness or disease.Onchocerciasis:Primarily affects skin, eyes & lymph nodes.In contrast to pathology in lymphatic filariasis, onchocerciasis damage elicited by microfilariae & not by adult parasites.Onchocerca microfilariae:Released from female worms causing most severe damage.Migrating microfilariae (exclusively found in interstitial fluids of skin & subdermal tissues not bloodstream).Cause changes in skin pigment & loss of elastic fibers a "hanging groin, severe intractable & intolerable pruritus.Blindness (primarily men) develops over many years - Due to microfilariae accumulation in vitreous humor.Are not blood borne & hence, concentrate & remain in eye.Visual clouding, photophobia & ultimately retinal damage a Incurable blindness.(Ref: Harrison 19/e p1420).