Researchers found a brain-eating amoeba in the waters of three National Park sites — Yellowstone, Grand Teton, and Lake Mead National Recreation Area — with Olympic National Park and Newberry National Volcanic Monument testing negative.
Affected locations include Firehole River, Boiling River, and Lewis Lake Hot Springs in Yellowstone; Polecat, Huckleberry, and Granite Hot Springs in Grand Teton; and multiple hot springs in Lake Mead, Nevada.
The amoeba was found in 63 of 185 water samples, or 34%, across these three sites.
High concentrations of this brain-eating amoeba, “Naegleria fowleri,” are the cause of primary amoebic meningoencephalitis (PAM) with a fatality rate of 98%.
This amoeba can enter the brain through the nose while swimming, causing brain swelling and tissue destruction. Death typically occurs within 1 to 7 days of infection.
Researchers say as climate change raises temperatures, the amoeba is now spreading northward despite typically being found in warm water in southern states. The amoeba thrives in water ranging from 60 to 115 degrees Fahrenheit.
Those conducting the study called for informational signs and public warnings at affected sites, as well as increased monitoring and risk management strategies.
There are no U.S. government standards for safe or unsafe concentrations of the amoeba in water used recreationally.
