Brain Eater Amoeba: A Case Report

A free-living amoeba, Naegleria fowleri, can live in both warm fresh water and soil. It causes the deadly central nervous system (CNS) infection known as primary amebic meningoencephalitis (PAM).

A 36-year-old male with no comorbidities presented with headache and high-grade fever for 3 days and was admitted with an episode of generalized tonic-clonic seizures (GTCS). He had a nasal bone fracture at the age of 15 years. No history of bathing in lake or pond water. On examination, the patient was febrile with a stiff neck. Initially treated as acute pyogenic meningoencephalitis, as initial cerebrospinal fluid (CSF) and blood pictures were suggestive of the same. CSF Gram stain was negative, but CSF wet mount yielded a motile trophozoite resembling N. fowleri, later confirmed with polymerase chain reaction (PCR) and Sanger sequencing. His wife revealed he was using tap water for "ritual nasal rinsing" as a part of religious practices.

PAM. He expired due to recurrent episodes of ventricular tachycardia (VT). Epidemiological link was confirmed by analysis of tap water, which also showed N. fowleri. Discussion: When making a differential diagnosis for any suspected case of pyogenic meningoencephalitis, preventable yet fatal PAM should be taken into account. Asking about freshwater exposure, including the history of nasal rinsing, and considering a simple CSF wet mount examination in all "Gram stain negative CSF samples" guides in early diagnosis.