Naegleria fowleri in Well Water

摘要

To the Editor: Naegleria fowleri, a protozoon found in hot springs and warm surface water, can cause pri-mary amebic meningoencephalitis in humans. A survey of drinking water supply wells in Arizona determined that wells can be colonized and may be an unrecognized source of this or-ganism that could present a human health risk.N. fowleri is a free-living amebo-. agellate found in warm bodies of wa-ter such as ponds, irrigation ditches, lakes, coastal waters, and hot springs and can cause primary amebic menin-goencephalitis. Humans come into contact with N. fowleri by swimming or bathing, particularly in surface wa-ters. The ameba enters the nasal pas-sages, penetrates the nasopharyngeal mucosa, and migrates to the olfactory nerves, eventually invading the brain through the cribriform plate (1). From 1995 to 2004, N. fowleri killed 23 per-sons in the United States (2), includ-ing 2 children in the Phoenix, Arizona, area in 2002, who had been exposed to well water but had not consumed it (3). There have been 6 documented deaths in 2007, all in warmer regions (Arizona, Texas, Florida) (4).