A rare brain-eating amoeba has been detected in recreational waters at several western US national parks, including Lake Mead, Grand Teton and Yellowstone, according to a study by the US Geological Survey.
Researchers found Naegleria fowleri in about one-third of 185 samples taken from 40 thermally impacted sites across five national parks and recreation areas. The organism was specifically identified in samples from Lake Mead, Grand Teton and Yellowstone.
Naegleria fowleri thrives in warm freshwater and can cause primary amebic meningoencephalitis (PAM), a fatal brain infection. While fewer than 10 cases occur annually in the US, the fatality rate is 98%, with only four survivors out of 167 cases since 1962.
The study underscores the need for enhanced monitoring and public awareness, particularly as rising global temperatures may expand the amoeba's range. A National Park Service spokesperson noted that infections remain extremely rare and no new nationwide warnings are warranted, but individual parks will issue advisories as needed.
