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Naegleria fowleri
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Acanthamoeba species
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Balamuthia mandrillaris
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| Route
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Essentially direct inoculation of brain via nasal passages
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Inoculation into skin or lung, then disseminates hematogenously with brain tropism
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| Clinical presentation
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Primary amoebic meningoencephalitis (PAM), with fulminant disease within days and death within 1-2 weeks
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Granulomatous amoebic encephalitis (GAE), with subacute presentations followed by fatal acute stage; may have cutaneous or sinus lesions; amebic keratitis
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GAE as well, similarly subacute; may have skin lesions
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| Risk factors
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Immunocompetent children or young adults with recreational warm fresh-water exposure
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Immunocompromised people; contact lens wearers, for keratitis
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Immunocompromised people, but also immunocompetent children and elderly, and Hispanics
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| Epidemiology
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Worldwide, warm freshwater up to 45ºC (includes hot springs)
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Worldwide in water and soil
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Worldwide in water and soil, more cases in South America and US
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| Neuroimaging
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Nonspecific
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Space-occupying or ring-enhancing lesion (GAE)
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Space-occupying or ring-enhancing lesion
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| Diagnosis
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CSF wet mount or PCR
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Cysts in brain biopsy, immunostaining or PCR; trophozoites or cysts on corneal scraping
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Cysts in brain biopsy, immunostaining or PCR
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| Treatment
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Intrathecal and intravenous amphotericin B, azoles, rifampin, miltefosine
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Pentamidine, azoles, flucytosine, sulfadiazine, miltefosine, amikacin, voriconazole
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Pentamidine, azithromcin, fluconazole, sulfadiazine, flucytosine, miltefosine
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