Tropical Parasitology

: 2020  |  Volume : 10  |  Issue : 2  |  Page : 150--152

Survival of primary amebic meningoencephalitis by Naegleria fowleri: First reported case from Tamil Nadu, South India

Venkatesh Perumalsamy1, Raja Sundaramoorthy2, Vithiya Ganesan2, VG Geni2,  
1 Department of Neurology, Velammal Medical College Hospital and Research Institute, Madurai, Tamil Nadu, India
2 Department of Microbiology, Velammal Medical College Hospital and Research Institute, Madurai, Tamil Nadu, India

Correspondence Address:
Vithiya Ganesan
4/437, Babu Nagar Main Road, Anuppanadi, Madurai - 625 009, Tamil Nadu


A case of primary amebic meningoencephalitis (PAM) in a 47-year-old male is described. The disease may have been contracted during bathing. The source of water was from a pond. The clinical presentation, the isolation of the ameba from the cerebrospinal fluid, and the response to amphotericin B are all consistent with the diagnosis of PAM. To our knowledge, this is the first case of PAM to be reported in Tamil Nadu, India.

How to cite this article:
Perumalsamy V, Sundaramoorthy R, Ganesan V, Geni V G. Survival of primary amebic meningoencephalitis by Naegleria fowleri: First reported case from Tamil Nadu, South India.Trop Parasitol 2020;10:150-152

How to cite this URL:
Perumalsamy V, Sundaramoorthy R, Ganesan V, Geni V G. Survival of primary amebic meningoencephalitis by Naegleria fowleri: First reported case from Tamil Nadu, South India. Trop Parasitol [serial online] 2020 [cited 2021 Apr 11 ];10:150-152
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Free-living amebae such as Acanthamoeba, Naegleria, and Balamuthia are present ubiquitously in aquatic habitats, worldwide. Among the species of the genus Naegleria, Naegleria fowleri is the only species pathogenic to humans. In particular, children and young adults are affected as the cribriform plate through which the parasite enters the central nervous system is more porous in them.

 Case History

A 47-year-old male brought to the emergency room with complaints of headache and vomiting since morning. After bathing in a river, within hours, he developed headache and vomiting. Progressively, he developed altered sensorium. He had a head injury 7 years back after which he has cribriform base plate defect and gives a history of episodes of cerebrospinal fluid (CSF) rhinorrhea. On physical examination, the patient was drowsy, responding to painful stimulus, and afebrile. Blood pressure was 180/100 mmHg. In view of risk of aspiration and impending respiratory failure, the patient was intubated.

Laboratory data included a total leukocyte count of 14,400/mm3, with 81% neutrophils, 9.2% lymphocytes, 7.3% monocytes, and 2.1% eosinophils. The hemoglobin concentration was 18.3 g/dl. No parasites were detected in the peripheral smear. Electrolyte picture showed sodium at 142 mmol/l, potassium at 5 mmol/liter, chloride at 99 mmol/l, bicarbonate at 26 mmol/l, phosphorus at 4.2 mg/dl, blood urea at 35 mg/dl, serum calcium level of 9.9 mg%, random blood sugar level of 73 mg/dl, erythrocyte sedimentation rate 21 mm/h, and procalcitonin 4.66 ng/ml (normal <0.1 ng/ml).

The CSF was cloudy, and the analysis showed sugar at a concentration of 45 mg/dl, proteins at a concentration of 166 mg/dl, and a cell count of 30 cells/mm3, with 70% neutrophils and 30% lymphocytes. Gram staining showed numerous polymorphonuclear leukocytes but no bacteria. Examination of a wet mount showed actively motile trophozoites, suggestive of primary amebic meningoencephalitis (PAM) [Figure 1]. CSF sediment culture on 1.5% nonnutrient agar preseeded with a lawn culture of Escherichia coli did not yield any growth. Flagellation test in distilled water was positive after 4 h. Bacteriological culture yielded no growth after 48 h of incubation.{Figure 1}

Liposomal amphotericin B 150 mg was given intravenously, and azithromycin was subsequently added. There was progressive deterioration of consciousness and a nonreactive pupillary reaction, and he developed acute kidney injury with blood urea 53 mg/dl and creatinine 2.4 mg/dl. Due to financial constraints, the patient could not continue the treatment in our hospital. Guarded prognosis was explained and the patient was discharged against medical advice. He was then admitted to a tertiary care government hospital. He gradually recovered and discharged after a week of successful treatment with conventional amphotericin B. Informed consent form was obtained from the patient.


PAM is a very rare entity. Incubation period is usually 2–8 days but can present within 24 h.[1],[2] In the present case, due to preexisting cribriform base plate defect [Figure 2], he developed symptoms within hours of exposure to water. The presence of N. fowleri in aquatic habitats and sewage canals in India has been established.[3],[4],[5] To date, there are 16 reported cases from India.[6] It is also intriguing to note that despite the proven prevalence of these free-living amebae in freshwater bodies, only very few cases reported from India. However, this represents only tip of the iceberg. This deadly clinical condition is often misdiagnosed as bacterial meningitis and hence grossly underreported. Very low autopsy rate could also be a reason for underreporting in India. The need for a high index of clinical suspicion in certain clinical settings cannot be overemphasized. It is imperative to get a complete and precise clinical history. Hence, CSF wet mount examination should form a part of regular microbiological analysis in purulent CSF samples without any bacteria. Even if immediate wet mount examination is not possible, the sample can be stored at room temperature. Next day, the flagellated trophozoites can be demonstrated from the sample. Recently, a noninvasive diagnostic method has been proposed by recovering motile trophozoites from saline wash solution of the nasal cavity.[7]{Figure 2}

Amphotericin B is the only drug with anti-amebicidal properties proved in vitro and by clinical case reports. Other drugs recommended by the CDC include miltefosine, fluconazole, and azithromycin.[8] To date, there are not more than a dozen survivors worldwide. Since this brain-eating ameba is a thermophilic organism, it is known to proliferate in warm water. In tropical countries like India, it is likely that more cases can occur in the future due to global warming and it is the need of the hour that all medical fraternities of health community should have a first-hand knowledge of this organism to make a timely diagnosis and save patients' lives. Periodic chlorination of these reservoirs can check the spread of this infection as well as other microorganisms.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

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