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Infections with free-living amebae

Govinda S Visvesvara1

  • 1Division of Foodborne, Waterborne & Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.

Handbook of Clinical Neurology
|July 9, 2013
PubMed

Insights

Free-living amebae like Acanthamoeba, Balamuthia, and Naegleria cause serious central nervous system infections. This review covers their biology, diseases (GAE and PAM), diagnosis, and epidemiology.

Area of Science:

  • Medical Microbiology
  • Infectious Diseases
  • Parasitology

Background:

  • Free-living amebae (FLA) such as Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri are pathogenic eukaryotes capable of causing severe infections in humans and animals.
  • These amebae infect the central nervous system (CNS), leading to distinct clinical syndromes with varying prognoses.

Observation:

  • Acanthamoeba spp. cause chronic granulomatous amebic encephalitis (GAE), particularly in immunocompromised individuals, and also Acanthamoeba keratitis. Balamuthia mandrillaris causes GAE in both immunocompromised and immunocompetent hosts, affecting disseminated organs.
  • Naegleria fowleri is responsible for acute, rapidly fatal primary amebic meningoencephalitis (PAM) in young individuals exposed to warm freshwater.
  • Sappinia pedata has been implicated in a single case of amebic meningoencephalitis.

Findings:

  • The review details the biology, clinical presentations, and diagnostic methods for GAE and PAM.
  • Epidemiological factors contributing to these infections are discussed.
  • Understanding the pathogenesis and transmission is crucial for effective management.

Implications:

  • This comprehensive review aids in understanding the diverse clinical spectrum and diagnostic challenges posed by pathogenic free-living amebae.
  • It highlights the need for increased awareness and improved diagnostic and therapeutic strategies for these rare but devastating infections.
  • Further research into the biology and epidemiology of these amebae is warranted to develop targeted interventions.
Keywords:
Acanthamoeba spp.Balamuthia mandrillarisNaegleria fowleriSappinia pedatagranulomatous amebic encephalitisprimary amebic meningoencephalitis

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