A five-month-old male infant presented with the history of fever and eye gaze from 3 days ago. Fever was mild to moderate without any associated chills. 
His birth history as well as developmental history was uneventful. The child was immunized up to date. The mother had no signs of mastitis. The child was apparently asymptomatic until two days before admission.
There was no evidence of other focal deficit, altered sensorium, or seizures. Patient neither swam nor recently took a bath in pond, pool, or lake. All relevant history for tuberculosis was negative.
CBC showed WBC 20,500 /mm3 (PMN 65%, lymphocytes 30%, monocytes 1%, eosinophils 1%, band cell 3%), hemoglobin 10.5 g/dL, hematocrit 31.9%, platelet count 731,000 /mm3. Serum electrolyte showed Na = 138, K = 5.7. ESR and CRP were 92 mm/h and 11.3 mg/L, respectively. Stool exam and urine analysis were normal; blood, urine, and stool culture were negative.
 A plain and contrast CT revealed communicated hydrocephalus. Following CT, lumbar puncture was done and CSF sent for microbiological and cytological analysis which revealed milky color, 2500 WBC cells/mm3 (PMN = 75%, Lymph = 25%) without any RBC with 391 mg/dL protein and 3 mg/dL of sugar. No bacteria or fungal elements were seen on gram stain. Bacterial culture was negative. Provisional diagnosis of acute bacterial meningitis was made, and the child was treated empirically by intravenous ceftriaxone 100 mg/kg/day and vancomycin 15 mg/kg/dose. 
Smear and PCR of CSF for tuberculosis was negative. Four days after starting of vancomycin and ceftriaxone, fever has not decreased so CSF examination was repeated. Second CSF analysis revealed 150 WBC cells/mm3 (PMN = 70%, Lymph = 30%), RBC 500 cells/mm3 with 121 mg/dL protein and 16 mg/dL of sugar. Naegleria Fowleri was seen on microscopic examination of wet preparation of CSF.
Following the demonstration of amoebae in CSF, clinical diagnosis of primary amoebic meningoencephalitis (PAM) was made. Rifampin was started in a dose of 10 mg/kg orally per day and Amphotericin B in a dose of 1 mg/kg/day. CSF culture for Naegleria was also positive. 
Three days after beginning of treatment with Amphotericin B and Rifampin, there was improvement in clinical signs and symptoms but fever has not decreased yet, so brain MRI was performed that revealed just hydrocephalus (Figure 1). The patient was referred to the Postgraduate Institute for the insertion of a ventriculoperitoneal shunt. Fever discontinued after surgery. After complete treatment, the patient was discharged. On followup, two months later the patient was totally asymptomatic.