A 16-year-old boy who swam in a warm stagnant pond two days ago presents with sudden-onset severe headache, high fever, neck stiffness, and altered sensorium. CSF shows neutrophilic pleocytosis with red cells and low glucose. Wet mount of CSF reveals actively motile trophozoites with blunt pseudopodia. The drug of choice is:

• A Amphotericin B given intravenously and intrathecally ✓
• B Metronidazole intravenously
• C Acyclovir intravenously
• D Albendazole plus praziquantel

Explanation

Naegleria fowleri, the free-living amoeba of warm fresh water, enters through the cribriform plate during swimming and causes primary amoebic meningoencephalitis, a rapidly fatal illness with purulent, often haemorrhagic CSF. Motile trophozoites with blunt pseudopodia on wet mount are diagnostic. High-dose amphotericin B, given intravenously and intrathecally, is the drug of choice, occasionally combined with miltefosine. Metronidazole targets Entamoeba and does not reliably kill Naegleria, and acyclovir addresses viral encephalitis.

Reference: Paniker's Textbook of Medical Parasitology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.