the microscopic ameba (a single-celled living organism) Naegleria fowleri.

Risk Factors

Bodies of warm freshwater, such as lakes and riversGeothermal (naturally hot) water, such as hot springsWarm water discharge from industrial plantsGeothermal (naturally hot) drinking water sourcesSwimming pools that are poorly maintained, minimally-chlorinated, and/or un-chlorinatedWater heaters. Naegleria fowleri grows best at higher temperatures up to 115°F (46°C) and can survive for short periods at higher temperatures.2, 3SoilNaegleria fowleri is not found in salt water, like the ocean.

Prevention

Infection is rare and typically occurs when people go swimming or diving in warm freshwater places, like lakes and rivers. Very rarely, infections have been reported when people submerge their heads, cleanse their noses during religious practices, or irrigate their sinuses (nose) using contaminated tap or faucet water. Naegleria fowleri can grow in pipes, hot water heaters, and water systems, including treated public drinking water systems.

Naegleria fowleri infects people when water containing the ameba enters the body through the nose.