The following is information about Nagleria fowleri, amoebas that kill humans by eating their brains:

THE CULPRIT: A species of amoeba known as Naegleria fowleri is found around the world in water and soil. In rare cases, they can latch onto the nasal cavity of people swimming in water where the amoeba live and will eat away the person's brain tissue.

DANGER: According to the Centers for Disease Control and Prevention, Naegleria infected 23 people from 1995 to 2004. This year health officials say they've noticed a spike in infections, with six Naegleria-related cases so far — all of them fatal.

PREVENTION: Health experts say people should stay away from warm, standing water. If they go swimming in such places, people should wear nose clips.