Epidemiology and Infection

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Epidemiology and Infection (2010), 138:968-975 Cambridge University Press
Copyright © Cambridge University Press 2009 This is a work of the U.S. Government and is not subject to copyright protection in the United States

Original Papers


The epidemiology of primary amoebic meningoencephalitis in the USA, 1962–2008

J. S. YODERa1 c1, B. A. EDDYa1a2, G. S. VISVESVARAa1, L. CAPEWELLa1 and M. J. BEACHa1

a1 Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
a2 Rollins School of Public Health, Emory University, Atlanta, GA, USA
Article author query
yoder js [PubMed]  [Google Scholar]
eddy ba [PubMed]  [Google Scholar]
visvesvara gs [PubMed]  [Google Scholar]
capewell l [PubMed]  [Google Scholar]
beach mj [PubMed]  [Google Scholar]


Naegleria fowleri, a free-living, thermophilic amoeba ubiquitous in the environment, causes primary amoebic meningoencephalitis (PAM), a rare but nearly always fatal disease of the central nervous system. While case reports of PAM have been documented worldwide, very few individuals have been diagnosed with PAM despite the vast number of people who have contact with fresh water where N. fowleri may be present. In the USA, 111 PAM case-patients have been prospectively diagnosed, reported, and verified by state health officials since 1962. Consistent with the literature, case reports reveal that N. fowleri infections occur primarily in previously healthy young males exposed to warm recreational waters, especially lakes and ponds, in warm-weather locations during summer months. The annual number of PAM case reports varied, but does not appear to be increasing over time. Because PAM is a rare disease, it is challenging to understand the environmental and host-specific factors associated with infection in order to develop science-based, risk reduction messages for swimmers.

(Accepted September 18 2009)

(Online publication October 22 2009)

Key Words:Infectious disease epidemiology; parasitic disease epidemiology and control; water-borne infections


c1 Author for correspondence: J. S. Yoder, 4770 Buford Highway, NE Mail Stop F-22, Atlanta, GA 30341, USA. (Email: jey9@cdc.gov)