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Primary amebic meningoencephalitis: a review of Naegleria fowleri and analysis of successfully treated cases

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Abstract

Primary amebic meningoencephalitis (PAM) is a necrotizing and hemorrhagic inflammation of the brain and meninges caused by Naegleria fowleri, a free-living thermophilic ameba of freshwater systems. PAM remains a neglected disease that disproportionately affects children in tropical and subtropical climates, with an estimated mortality rate of 95–98%. Due to anthropogenic climate change, the average temperature in the USA has increased by 0.72 to 1.06 °C in the last century, promoting the poleward spread of N. fowleri. PAM is often misdiagnosed as bacterial meningitis or viral encephalitis, which shortens the window for potentially life-saving treatment. Diagnosis relies on the patient’s history of freshwater exposure and the physician’s high index of suspicion, supported by cerebrospinal fluid studies. While no experimental trials have been conducted to assess the relative efficacy of treatment regimens, anti-amebic therapy with adjunctive neuroprotection is standard treatment in the USA. We performed a literature review and identified five patients from North America between 1962 and 2022 who survived PAM with various degrees of sequelae.

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Data availability

Information from case reports can be found on PubMed or Google Scholar. Data from the Waterborne Disease and Outbreak Surveillance System at CDC is available upon request. Interested parties should visit their website.

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Authors and Affiliations

  1. Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA

    Ashton D. Hall, Julia E. Kumar & Keith M. Luckett

  2. Department of Emergency Medicine, University of Cincinnati College of Medicine, 3230 Eden Avenue, Cincinnati, OH, 45267, USA

    Claire E. Golba & Whitney K. Bryant

  3. Department of Environmental and Public Health Sciences, University of Cincinnati College of Medicine, Cincinnati, OH, USA

    Whitney K. Bryant

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  1. Ashton D. Hall
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  2. Julia E. Kumar
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Contributions

Ashton D. Hall: Conceptualization, Writing – original draft preparation, figs. 1 and 2, tables 1 and 2, and revisions. Julia E. Kumar: Writing – review & editing. Claire E. Golba: Writing – review & editing. Keith M. Luckett: Writing – review & editing. Whitney K. Bryant: Writing – review & editing, Supervision.

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Correspondence to Whitney K. Bryant.

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As this is a literature review based on publicly available data, no identifiable information was used. Therefore, ethical approval was not needed or obtained. Of note, Kali Hardig’s name and story has been widely publicized since her infection in 2013.

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Hall, A.D., Kumar, J.E., Golba, C.E. et al. Primary amebic meningoencephalitis: a review of Naegleria fowleri and analysis of successfully treated cases. Parasitol Res 123, 84 (2024). https://doi.org/10.1007/s00436-023-08094-w

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