Primary Amebic Meningoencephalitis (PAM)

Naegleria fowleri

Primary Amebic Meningoencephalitis (PAM) is a rare and typically fatal disease caused by Naegleria fowleri. Naegleria fowleri (also known as the "brain-eating ameba") is a warm-water-loving ameba (single-celled organism) found around the world, often in warm or hot freshwater lakes, rivers and hot springs. When water containing the Naegleria fowleri ameba enters the nose, the ameba can travel up the nose and into the brain. This destroys brain tissue and causes brain swelling and death.

Naegleria fowleri is normally found in the natural environment and is well adapted to surviving in various habitats, particularly warm-water environments up to 115 F. The ameba becomes dormant in cold temperatures and can survive buried in the sediment of water bodies. There are no known ways to control the amount of natural Naegleria fowleri in lakes and rivers. The best way to prevent infection is to prevent water from going up the nose.

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Last Revised: July 18, 2018