Q.90 Which of the following is a main symptom of infection by Wuchereria bancrofti?
(A) Swelling of limbs
(B) Skin rashes
(C) Blindness
(D) Brain cyst
Swelling of limbs is the main symptom of Wuchereria bancrofti infection. This filarial nematode causes lymphatic filariasis, leading to lymphedema and elephantiasis through lymphatic obstruction.
Options Explained
Swelling of Limbs (A)
Wuchereria bancrofti microfilariae and adults block lymphatics, causing chronic lymphedema (elephantiasis) with massive limb swelling, skin thickening, and fibrosis. This hallmark symptom affects 90% of cases, appearing years post-infection.
Skin Rashes (B)
Skin rashes occur transiently in acute adenolymphangitis episodes but are secondary to bacterial superinfections, not the primary filarial pathology. Chronic cases show hyperkeratosis, not rashes.
Blindness (C)
Blindness characterizes onchocerciasis (river blindness by Onchocerca volvulus), not bancroftian filariasis, which targets lymphatics rather than eyes.
Brain Cyst (D)
Brain cysts typify neurocysticercosis (Taenia solium), a tapeworm infection unrelated to filarial nematodes like Wuchereria.
Swelling of limbs from Wuchereria bancrofti defines lymphatic filariasis, causing elephantiasis—a key tropical disease concept for NEET medical exams.
Pathophysiology of Lymphatic Filariasis
Adult worms (females 10 cm, males 4 cm) reside in lymphatics, provoking inflammation and obliteration. Microfilariae circulate nocturnally, transmitted by Culex/Anopheles mosquitoes. Chronic obstruction → protein-rich lymph stasis → edema → fibrosis.
| Symptom | Disease | Causative Agent |
|---|---|---|
| Limb Swelling | Lymphatic Filariasis | Wuchereria bancrofti |
| Skin Rashes | Secondary bacterial | Not primary |
| Blindness | Onchocerciasis | Onchocerca volvulus |
| Brain Cyst | Neurocysticercosis | Taenia solium |
Clinical Stages
-
Asymptomatic: Microfilaremia without symptoms.
-
Acute: Adenolymphangitis, hydrocele.
-
Chronic: Elephantiasis (limbs, genitals), tropical pulmonary eosinophilia.
Why Option (A) is Correct
WHO/CDC recognize lymphedema/elephantiasis as the signature pathology of Wuchereria bancrofti, distinguishing it from other parasites in exam contexts.
