Naegleria (nay-GLEER-e-uh) infection is a rare and usually fatal brain infection caused by an amoeba commonly found in freshwater lakes, rivers and hot springs. Exposure occurs during swimming or other water sports.
The amoeba — called Naegleria fowleri — travels up the nose to the brain, where it causes severe damage. Most people who have naegleria infection die within a week.
Millions of people are exposed to the amoeba that causes naegleria infection each year, but only a handful of them ever get sick from it. Health officials don't know why some people develop naegleria infection while others don't.
Avoiding warm bodies of fresh water and wearing nose clips while in the water may help prevent such infections.