A previously healthy adolescent swims in a warm stagnant pond and three days later develops high fever, severe frontal headache, vomiting, and rapidly progressive coma. CSF shows neutrophilic pleocytosis with low glucose. Wet mount examination of CSF demonstrates actively motile amoebae that convert to flagellate forms. The drug of choice is:

• A Metronidazole
• B Ivermectin
• C Nitazoxanide
• D Amphotericin B ✓

Explanation

Naegleria fowleri causes primary amoebic meningoencephalitis in healthy swimmers after organisms enter through the cribriform plate. The trophozoites transform to biflagellate forms in CSF, a feature unique to Naegleria. Treatment is high-dose intravenous and intrathecal amphotericin D, though mortality remains very high because the disease progresses within days. Metronidazole targets Entamoeba and other anaerobic protozoa but is ineffective here.

Reference: Paniker's Textbook of Medical Parasitology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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