A fatal case of primary amebic meningoencephalitis (PAM) in a 5-month-old infant is described. The disease may have been contracted during bathing. The source of water was from an artificial well. The clinical presentation, the isolation of the ameba from the cerebrospinal fluid, the poor response to amphotericin B, and the ultimate fatal outcome are all consistent with the diagnosis of PAM. On the basis of its ability to grow at temperatures above 30°C, the morphology of the trophozoite, and the presence of flagellate forms, the ameba was identified as Naegleria fowleri. Pathogenic N. fowleri amebae were recovered from samples of water from the well. To our knowledge this case represents the second case of PAM in an infant in the absence of the history of swimming.Naegleria fowleri, a free-living ameba, is ubiquitous and worldwide in distribution. It can infect humans and cause significant disease. It penetrates through the cribriform plate and can cause fulminant and rapidly fatal meningoencephalitis. Most of the infections have been associated with bathing in streams, ponds or lakes, and indoor swimming baths where the water is warm (7). We report on a case of primary amebic meningoencephalitis (PAM) in an infant who had not been swimming. To our knowledge this is the first case of PAM to be reported in Mangalore, India.Case history. A 5-month-old infant presented with a history of fever, vomiting for 1 week, and convulsions for 3 days. On physical examination, the child was febrile (38.5°C), continuous convulsions were present, and the pupils were reactive. There was a progressive deterioration of consciousness, leading to coma. There was no significant finding in the cardiovascular system or respiratory system or by abdominal examination. A computed tomography scan showed mild effacement of the basal cisterns and a thin hypodense collection in bilateral frontal convexity, suggesting a possibility of subdural hygroma or subdural effusion.Laboratory data included a total leukocyte count of 7,300/ mm 3 , with 71% neutrophils, 26% lymphocytes, and 3% eosinophils. The hemoglobin concentration was 10.2 g/dl. No parasites were seen in the peripheral smear. The blood electrolyte picture showed sodium at 133 mmol/liter, potassium at 4.4 mmol/liter, chloride at 95 mmol/liter, bicarbonate at 18.6 mmol/liter, phosphorus at 4.7 mg/dl, blood urea nitrogen at 14 mg/dl, a serum calcium level of 9.2 mg%, and a random blood sugar level of 120 mg/dl.The cerebrospinal fluid (CSF) was cloudy and hemorrhagic; and analysis showed the presence of sugar at a concentration of 10 mg/dl, proteins at a concentration of 361 mg/dl, and a cell count of 130 cells/mm 3 , with 80% neutrophils and 20% lymphocytes. Gram staining showed numerous polymorphonuclear leukocytes but no bacteria. Examination of a wet mount showed actively motile trophozoites suggestive of PAM. A Giemsa-stained smear showed trophozoites.CSF sediment culture on 1.5% nonnutrient agar preseeded with a lawn culture of Escherichia coli yielded oval, motile, flagellated for...
