Naegleria fowleri is an amoeba that lives predominately in warm freshwater. Naegleria fowleri is acquired by people when infected water is forcibly aspirated into the nose. This can occur through recreational swimming, diving, or during sports like water skiing. Once acquired, the amoeba travels into the brain, causing primary amoebic meningoencephalitis (PAM). In the popular press, Naegleria fowleri is sometimes called the "brain-eating amoeba," and meningoencephalitis is sometimes referred to as Naegleriasis.
Naegleria fowleri is found around the world. The ameba can be found in: Bodies of warm freshwater, such as lakes and rivers, Geothermal (naturally hot) water, such as hot springs, Warm water discharge from industrial plants, Geothermal (naturally hot) drinking water sources, Swimming pools that are poorly maintained, minimally-chlorinated, and/or un-chlorinated, Water heaters. Naegleria fowleri grows best at higher temperatures up to 115°F (46°C) and can survive for short periods at higher temperatures. Soil Naegleria fowleri is not found in salt water, like the ocean.
Naegleria fowleri infects people when water containing the ameba enters the body through the nose. Infection is diagnosed by examining spinal fluid under the microscope to identify the amoeba.
The treatment of choice is an intravenous drug called amphotericin B. Amphotericin B may also be instilled directly into the brain. Miltefosine is a drug that has shown promise, and it is available through the Centers for Disease Control and Prevention. Treatment should be initiated as rapidly as possible, and immediate consultation with an infectious-diseases expert is highly recommended.