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Year : 2019  |  Volume : 37  |  Issue : 1  |  Page : 120--122

Primary amoebic meningoencephalitis in an infant

Neetu Mittal1, Lokesh Mahajan2, Zahid Hussain2, Parakriti Gupta3, Sumeeta Khurana3,  
1 Department of Microbiology, QRG Central Hospital and Research Centre, Faridabad, Haryana, India
2 Department of Pediatrics, QRG Health City, Faridabad, Haryana, India
3 Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Correspondence Address:
Dr. Sumeeta Khurana
Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh - 160 012


Primary amoebic meningoencephalitis is rare but fatal disease encountered in immunocompetent individuals. Here, we present a case of a previously healthy 8-month-old female child, who presented with features of meningoencephalitis of 2 days' duration. Rapidly moving trophozoites of amoeba were observed in cerebrospinal fluid, which were confirmed to be Naegleria fowleri on polymerase chain reaction. Broad-spectrum antimicrobial therapy with ceftriaxone, vancomycin, amphotericin B and acyclovir was initiated. However, the patient deteriorated and left the hospital against medical advice. The isolation of N. fowleri in this case demands for increased awareness for prompt diagnosis and management in view of its high mortality.

How to cite this article:
Mittal N, Mahajan L, Hussain Z, Gupta P, Khurana S. Primary amoebic meningoencephalitis in an infant.Indian J Med Microbiol 2019;37:120-122

How to cite this URL:
Mittal N, Mahajan L, Hussain Z, Gupta P, Khurana S. Primary amoebic meningoencephalitis in an infant. Indian J Med Microbiol [serial online] 2019 [cited 2021 Mar 7 ];37:120-122
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Free-living amoebae are ubiquitously present in diverse marine and soil habitations. These include Naegleria, Acanthamoeba, Balamuthia, Vahlkampfia and Hartmannella, of which only few species are pathogenic to humans, leading to infrequent but deadly central nervous system (CNS) infections.[1]

Primary amoebic meningoencephalitis (PAM) caused by Naegleria fowleri infection is reported mainly in healthy children and young adults, in contrast to infections caused by Acanthamoeba and Balamuthia that are reported in immunocompromised patients.[1] The protozoan gains entry into CNS through cribriform plate, usually after swimming and recreational activities[1],[2] or rarely after nasal irrigation and bathing in infected water.[3] Few cases of PAM have also been reported post-organ transplant.[4] PAM is invariably associated with high mortality of nearly 95%.[1]

 Case Report

We present a case of a previously healthy 8-month-old female child, resident of Haryana, who presented to outpatient department of a private hospital on 26th May 2018 with complaints of fever associated with rigors and chills, abnormal body movements, vomiting, generalised tonic–clonic seizures, decreased oral acceptance and decreased urine output for 2 days. On physical examination, the child was febrile, anicteric, drowsy with bilaterally dilated pupils, sluggishly reacting to light, suggestive of sepsis and meningoencephalitis. The child was admitted in intensive care unit and was further worked up, and lumbar puncture was performed. Blood and cerebrospinal fluid (CSF) findings of this case are shown in [Table 1] and [Table 2], respectively. Briefly, the peripheral blood showed marked anisocytosis with predominance of microcytic, hypochromic red blood cells and leucopenia with neutrophil predominance. Blood culture for bacterial and fungal pathogens was negative. C-reactive protein and adenosine deaminase levels were raised. Raised CSF pressure was observed during lumbar puncture, proteins were increased, glucose was reduced and there was increased production of polymorphonuclear cells in CSF. Rapidly moving trophozoites of amoeba were observed in CSF, which were confirmed to be N. fowleri on microscopy and polymerase chain reaction,[5] performed at the Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh [Figure 1].{Table 1}{Table 2}{Figure 1}

Computed tomography scan of the brain showed mild leptomeningeal enhancement, involving bilateral cerebral hemispheres, suggestive of meningitis and mildly prominent third and fourth ventricles suggestive of non-obstructing hydrocephalus. Chest X-ray showed opaque left hemilung with ipsilateral mediastinal shift.

The child was started on parenteral phenytoin and midazolam to control seizures, followed by mannitol to decrease the raised intracranial pressure (ICP). Broad-spectrum antimicrobial therapy with ceftriaxone, vancomycin, amphotericin B (AMB) and acyclovir was initiated. Elective endotracheal intubation and mechanical ventilation were done in view of deteriorating Glasgow coma scale. Later, parents left the hospital against medical advice within 48 h.


The PAM case described in this paper is very unusual as it is reported in an 8-month-old child with no predisposing factors for acquisition of disease. The youngest survivor of Naegleria has been reported to be a 25-day-old boy.[6] The case presented in the month of May, supporting the observation that N. fowleri infections are associated with hot season. PAM poses a diagnostic challenge due to nonspecific clinical features resembling acute pyogenic meningitis. In most cases, diagnosis is not made since the disease is not suspected clinically and appropriate tests are not undertaken. Due to its rapid progression, illness follows a devastating course and the patients usually succumb within a week, if not treated aggressively. Laboratory findings seen in PAM patients are increased leucocytes predominantly the polymorphs, raised proteins, reduced glucose level and absence of bacteria.[1],[7] The radiological findings of our case correlated with the common presentation of PAM cases reported earlier in the literature.[7] There are no clinical trials to date that assess the efficacy of various treatment regimens due to the rarity of N. fowleri infections in humans. Most of the information is based on either case reports or in vitro studies. The currently recommended drug of choice is AMB, but it is associated with a low cure rate, if administered as monotherapy. Other anti-infectives that have been used in different cases include fluconazole, miconazole, miltefosine, azithromycin and rifampin. Some of the other treatment regimens have also been proposed, making use of synergistic action of azithromycin and fluconazole or amphotericin or miltefosine.[7],[8] Patients who have survived the disease have been aggressively treated with combination of antibacterial and antifungal agents. Supportive management to decrease the raised ICP, inflammation and hypothermia is considered necessary. However, the survival rate also varies according to the strain infecting the patient. It has been hypothesized that the patients who have survived might be infected with less virulent strains as many patients have succumbed in spite of following the same treatment regimen.[8]

The patient reported in our study had no history of exposure to contaminated water such as ponds, lakes, etc., and is too young to swim; thus, the exact source of infection cannot be pointed out. However, these parasites are ubiquitously present in water and soil.[1] Recently, a study was conducted to determine the prevalence of free-living amoebae in water samples from North India. It was reported that free-living amoebae were present in 40% samples and Naegleria constituted 86% of the amoebae. However, all of the isolates were non-pathogenic species of Naegleria and only one was found to be pathogenic N. fowleri.[9] A total of 15 cases have been reported from India, of which 9 patients were treated successfully.[10] An upsurge in number of cases due to Naegleria in India can partly be attributed to heightened awareness for the disease and availability of advanced diagnostic modalities.

To conclude, the number of cases of the dreadful illness has risen significantly in the recent past. Therefore, there is an urgent need to raise the awareness among the clinicians for prompt diagnosis and management in view of the high mortality associated with the disease.

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

There are no conflicts of interest.


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