An adult male living near a fast-flowing river in Africa presents with itchy papular rash and visual impairment. Palpable subcutaneous nodules over bony prominences are noted. Microfilariae are absent from peripheral blood films. The most appropriate specimen for demonstrating microfilariae is:
- A Nocturnal thick blood smear
- B Skin snip biopsy ✓
- C Chyle urine sediment
- D CSF centrifuged deposit
Correct answer: B. Skin snip biopsy
Explanation
Onchocerca volvulus microfilariae remain confined to the dermis and subcutaneous tissues rather than circulating in blood, so the diagnostic test is demonstration of microfilariae in skin snips taken over iliac crests or scapulae. Adult worms live in subcutaneous nodules, and microfilariae reaching the eye cause river blindness. Blood films detect lymphatic filarial parasites, while chyluria relates to Wuchereria bancrofti obstructive disease.
Reference: Paniker's Textbook of Medical Parasitology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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