Behavioral and recreational risk factors for free-living amebic infections.

摘要

Free-living amebae of the genera Acanthamoeba, Balamuthia, Naegleria, and Sappinia are rare causes of infectious diseases in humans with the exception of Acanth amoeba keratitis (AK), which is reported in over 10,000 soft contact lens wearers annually worldwide. Unlike several Acanthamoeba species, which can cause both AK and granulomatous amebic encephalitis (GAE), only one species of Naegleria, Naegleria fowleri, is known to infect humans by causing an acute, fulminant, usually lethal, central nervous system (CNS) infection, known as primary amebic meningoencephalitis (PAM). Both Acanthamoeba species and N fowleri are distributed worldwide; found commonly in freshwater; and have even been isolated from tap water, air conditioning systems, and improperly maintained swimming pools.