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 Table of Contents  
Year : 2014  |  Volume : 4  |  Issue : 2  |  Page : 115-118  

Acanthamoeba meningoencephalitis in immunocompetent: A case report and review of literature

1 Department of Microbiology, Kasturba Medical College, Manipal University, Manipal, Karnataka, India
2 Department of Medicine, Kasturba Medical College, Manipal University, Manipal, Karnataka, India
3 Department of Pathology, Kasturba Medical College, Manipal University, Manipal, Karnataka, India

Date of Acceptance10-Sep-2014
Date of Web Publication12-Aug-2014

Correspondence Address:
Vinay Khanna
Department of Microbiology, Kasturba Medical College, Manipal - 576 104, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2229-5070.138540

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A 30-year-old manual laborer from Karnataka, India presented with intermittent low grade fever and diffuse headache for 1 month. On examination, patient had enlarged supraclavicular and cervical lymph nodes. Patient had positive Kernig's sign and neck stiffness. Motor, sensory and cranial nerve examinations were within the normal limits. Abdominal, cardiovascular and chest examination did not yield any positive findings. Contrast enhanced computed tomography head was normal. Patient was suspected to have extrapulmonary tuberculosis. Patient was started on antitubercular drugs. Diagnostic lumbar puncture was performed. Wet mount and Giemsa smear preparation of cerebrospinal fluid (CSF) showed trophozoites suggestive of Acanthamoeba. CSF was cultured onto non-nutrient agar with an overlay of Escherichia coli. Wet mount made from the culture media yielded cysts and trophozoites of Acanthamoeba spp. Patient was diagnosed with Acanthamoeba meningitis and was started on specific therapy with Rifampicin 600 mg once a day, Cotrimoxazole 960 mg twice-a-day and Fluconazole 400 mg once daily for 2 weeks. Patient had a complete recovery and was discharged from the hospital.

Keywords: Acanthamoeba spp, immunocompetant, meningoencephalitis

How to cite this article:
Khanna V, Shastri B A, Anusha G, Mukhopadhayay C, Khanna R. Acanthamoeba meningoencephalitis in immunocompetent: A case report and review of literature. Trop Parasitol 2014;4:115-8

How to cite this URL:
Khanna V, Shastri B A, Anusha G, Mukhopadhayay C, Khanna R. Acanthamoeba meningoencephalitis in immunocompetent: A case report and review of literature. Trop Parasitol [serial online] 2014 [cited 2022 Dec 3];4:115-8. Available from: https://www.tropicalparasitology.org/text.asp?2014/4/2/115/138540

   Background Top

Meningitis, in general is a disease, which results in fatal complications with delay in diagnosis and treatment. Meningitis with parasitic etiology is quite a rare scenario and meningitis with Acanthamoeba is a rarer phenomenon. Acanthamoeba is a free-living amoeba commonly found in fresh water. It is known to cause keratitis, granulomatous encephalitis and cutaneous lesions. In this case report, we present a patient with Acanthamoeba meningitis.

   Case report Top

A 30-year-old manual laborer, from Chitradurga, district in Karnataka, India presented with intermittent low grade fever and diffuse headache for 1 month. Patient had a history of loss of appetite and weight loss (about 3 kg) in the past month. There was no history of confusion, nausea, vomiting, lethargy, seizures, visual disturbance, cough, sputum production or hemoptysis. On examination, his vitals were normal. Patient had enlarged, non-tender, mobile 2 cm × 3 cm supraclavicular and 3 cm × 4 cm cervical lymph nodes and positive Kernig's sign and neck stiffness. Motor, sensory and cranial nerve examinations were within the normal limits. Abdominal, cardiovascular and chest examination did not yield any positive findings. There was no similar illness in the family. Patient did not have a history of diabetes mellitus and other comorbid illnesses. Considering the fact that tuberculosis is endemic in India, patient was initially suspected to have extra pulmonary tuberculosis (tuberculous meningitis). Patient was started on anti-tubercular drugs (rifampicin, pyrazinamide, ethambutol and isoniazid).

Complete blood counts, erythrocyte sedimentation rate, renal and liver function tests, serological tests for  Salmonella More Details (Widal test),  Brucella More Details (Standard agglutination test) and Rickettsial infections (Weil-Felix test) were within the normal limits. Contrast enhanced computed tomography head was normal. Diagnostic lumbar puncture was performed. Cerebrospinal fluid (CSF) analysis showed clear fluid, with lymphocyte predominant pleocytosis (207 cells/cubic mm) with low glucose (34 mg/dl), normal adenose deaminase and high protein levels (134 mg/dl). CSF was evaluated for bacterial meningitis including Mycobacterium tuberculosis (using fluorescence microscopy and polymerase chain reaction) and for Cryptococcus (using latex agglutination) and was found negative. Sputum was also evaluated for Mycobacterium tuberculosis and found negative. Patient was tested for human immunodeficiency virus (HIV) using serum ELISA and found negative. CSF was then evaluated for parasites. Wet mount of CSF showed few organisms with amoeboid movement, with the presence of acanthopodia suggestive of Acanthamoeba trophozoites [Figure 1]. Giemsa smear preparation of CSF showed features suggestive of trophozoites of Acanthamoeba. CSF was cultured onto non-nutrient agar with an overlay of  Escherichia More Details coli. Wet mount made from the culture media after 72 h yielded trophozoites and star shaped double walled cysts of Acanthamoeba spp. [Figure 2]. The CSF wet mount and culture findings were sent to Centers for Disease Control and Prevention, Atlanta and were confirmed to be trophozoites and cysts of Acanthamoeba respectively.
Figure 1: Trophozoites of Acanthamoeba with acanthapodias

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Figure 2: Cysts of Acanthamoeba

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After the recovery of Acanthamoeba from CSF, patient was diagnosed with Acanthamoeba meningoencephalitis and was started on specific therapy with rifampicin 600 mg once daily, trimethoprim sulfamethaxozole 960 mg twice-a-day and fluconazole 400 mg once daily. Patient had a complete recovery within 2 weeks of the above mentioned therapy and was discharged from the hospital. Patient came for follow-up after 2 weeks of discharge and was found to have no symptoms and signs of meningeal inflammation.

   Discussion Top

Acanthamoeba , a free living amoeba is commonly found in water resources such as swimming pools, lakes and rivers. It has also been isolated from contact lens cases and as contaminants in cell cultures. [1],[2],[3] The mode of transmission to humans is by inhalation or inoculation through skin lesions. [4] However, the patient presented in this case report, did not have contact with any water source. Non-exposure to fresh water is also noted in the previous case reports published on Acanthamoeba infections [Table 1]. Individuals having a poor immune status due to diseases such as diabetes, malignancies, tuberculosis, HIV infection or those who are on cancer chemotherapy or have undergone organ transplants are more susceptible to Acanthamoeba infection. [5],[6] In our report, patient was found to be immunocompetent. The common manifestations of Acanthamoeba infections in man are granulomatous encephalitis, keratitis and cutaneous lesions. [7] Acanthamoeba spp. is also known to cause chronic meningitis. In the past decade, there have been a few case reports of Acanthamoeba meningitis and intracranial lesions world-wide [Table 1].
Table 1: List of case reports on Acanthamoeba infections published over the years[9-16]

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Laboratory diagnosis of Acanthamoeba meningitis can be done using CSF wet mount and Geimsa-Wright staining technique. Acanthamoeba can also be cultured using non-nutrient agar with an overlay of E. coli or Enterobacter aerogenes.[4],[8] In this report, CSF showing pleocytosis with plenty of lymphocytes and neutrophils along with low glucose and high protein levels which were clinically indicative of central nervous system (CNS) infection with Acanthamoeba was seen. There are a number of studies stating the misdiagnosis of patients with Acanthamoeba infections with other medical conditions or infectious diseases. [17],[18] Our case report also shows a similar instance of misdiagnosis, where the patient was empirically started on anti-tubercular drugs as tuberculous meningitis was the initial probable diagnosis.

It is of paramount importance to identify patients with Acanthamoeba infections of the CNS as early diagnosis prevents mortality and serious complications, which is the norm in these infections. Recent studies show the importance of suspecting and evaluating patients for amoebic causes of CNS infections in order to prevent misdiagnosis and inappropriate treatment. [19],[20] Currently, there is no standard regimen for the treatment of Acanthamoeba infections. In the past a number of drugs were used alone and in combination for the treatment of CNS infection caused by Acanthamoeba. They were, ketoconazole, fluconazole, sulfadiazine, albendazole amphotericin-B, rifampicin, trimethroprim-sulfamethoxazole. [21],[12] Recent studies have shown good outcomes with a combination of rifampicin, trimethoprim sulfamethoxazole and ketoconazole. [22],[23] Our patient had a complete recovery with rifampicin, fluconazole and trimethoprim sulfamethoxazole.

   References Top

1.De Jonckheere, J.F. Review ecology of Acanthamoeba. Rev Infect Dis. 1991;13 Suppl 5:S385-7.  Back to cited text no. 1
2.Barbeau J, Buhler T. Biofilms augment the number of free-living amoebae in dental unit waterlines. TRes Microbiol. 2001;152:753-60.  Back to cited text no. 2
3.Nazar M, Haghighi A, Niyyati M, Eftekhar M, Tahvildar-Biderouni F, Taghipour N, et al. Genotyping of Acanthamoeba isolated from water in recreational areas of Tehran, Iran. J Water Health. 2011;9:603-8.  Back to cited text no. 3
4.Marciano-Cabral F , Cabral G. Acanthamoeba spp. as agents of disease in humans. Clin Microbiol Rev. 2003;16: 273-307.  Back to cited text no. 4
5.Feingold JM, Abraham J, Bilgrami S, Ngo N, Visvesara GS Edwards RL, et al. Acanthamoeba meningoencephalitis following autologous peripheral stem cell transplantation. Bone Marrow Transplant. 1998;22:297-300.  Back to cited text no. 5
6.Steinberg JP, Galindo RL, Kraus ES, Ghanem KG. Review Disseminated acanthamebiasis in a renal transplant recipient with osteomyelitis and cutaneous lesions: case report and literature review. Clin Infect Dis. 2002;35:e43-9.  Back to cited text no. 6
7.Siddiqui R, Khan N. Biology and pathogenesis of Acanthamoeba. Parasit & Vectors 2012;5:6.  Back to cited text no. 7
8.da Rocha-Azevedo B, Tanowitz HB, and Marciano-Cabral F. Diagnosis of infections caused by pathogenic free-living amoebae. Interdiscip Perspect Infect Dis 2009; 2009:251406.  Back to cited text no. 8
9.Sharma PP, Gupta P, Murali MV, Ramachandran VG. Primary amebic meningoencephalitis caused by Acanthamoeba: Successfully treated with cotrimoxazole. Indian Pediatr 1993;30:1219-22.  Back to cited text no. 9
10.Hamide A, Sarkar E, Kumar N, Das AK, Narayan SK, Parija SC. Acanthameba meningoencephalitis: A case report. Neurol India 2002;50:484-6.  Back to cited text no. 10
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11.Velho V, Sharma GK, Palande DA. Cerebrospinal acanthamebic granulomas. Case report. J Neurosurg 2003;99:572-4.   Back to cited text no. 11
12.Petry F , Torzewski M, Bohl J, Wilhelm-Schwenkmezger T, Scheid P, Walochnik J, et al. Early diagnosis of Acanthamoeba infection during routine cytological examination of cerebrospinal fluid. J Clin Microbiol. 2006;44:1903-4.   Back to cited text no. 12
13.Kaushal V, Chhina DK, Kumar R, Pannu H S, Dhooria HP, Chhina RS. Acanthamoeba encephalitis. Indian J Med Microbiol 2008; 26: 182-4.  Back to cited text no. 13
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14.Ranjan R, Handa A, Choudhary A, Kumar S. Acanthamoeba infection in an interhemisheric ependymal cyst: A case report. Surg Neurol 2009;72,185-9.  Back to cited text no. 14
15.Saxena A, Mittal S, Burman P, Garg P. Acanthameba meningitis with successful outcome. Indian J Pediatr 2009;76:1063-4.  Back to cited text no. 15
16.Binesh F, Karimi M, Navabii H. Unexpected postmortem diagnosis of Acanthamoeba meningoencephalitis in an immunocompetent child. BMJ Case Rep.2011 doi:10.1136/bcr.03.2011.3954.  Back to cited text no. 16
17.Rivera MA, Padhya TA. Acanthamoeba: A rare primary cause of rhinosinusitis. Laryngoscope.2002;112:1201-3.   Back to cited text no. 17
18.Shi WY, Gao H, Li SW, Wang FH, Xie LX. Clinical study of the treatment of Acanthamoeba keratitis by penetrating keratoplasty. Zhonghua Yan Ke Za Zhi. 2004;40:750-4.   Back to cited text no. 18
19.Schuster FL, Honarmand S, Visvesvara GV, Glaser CA. Detection of antibodies against free-living amoebae Balamuthia mandrillaris and Acanthamoeba species in a population of patients with encephalitis. Clin Infect Dis. 2006;42:1260-5.  Back to cited text no. 19
20.Kumar M, Jain R, Tripathi K, Tandon R, Gulati AK, Garg A et al. Acanthamoebae presenting as primary meningoencephalitis in AIDS. Indian J Pathol Microbiol 2007;50:928-30.  Back to cited text no. 20
21.Lalitha MK, Anandi V, Srivastava A, Thomas K, Cherian AM, Chandi SM. Isolation of Acanthamoeba culbertsoni from a patient with meningitis. J Clin Microbiol. 1985;21:666-7.  Back to cited text no. 21
22.Singhal T, Bajpai A, Kalra V, Kabra SK, Samantaray JC Satpathy G, et al. Successful treatment of Acanthamoeba meningitis with combination oral antimicrobials. Pediatr Infect Dis J. 2001;20:623-7.  Back to cited text no. 22
23.Gupta D, Panda GS, Bakhshi S. Successful treatment of Acanthamoeba meningoencephalitis during induction therapy of childhood acute lymphoblastic leukemia. Pediatr Blood Cancer 2008;50:1292-3.  Back to cited text no. 23


  [Figure 1], [Figure 2]

  [Table 1]

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