Brain-eating amoeba infection. Computer illustration of Naegleria fowleri protozoans infecting the brain. This organism is an opportunistic pathogen of humans, causing meningoencephalitis (inflammation of the brain and its surrounding membranes) when inhaled, often by children swimming in fresh water. Headaches, vomiting, sensory disturbance and a fatal coma may occur if the victim is not treated. Treatment is with antiprotozoal drugs.