Naegleria fowleri is a one-celled organism that the U.S. Centers for Disease Control explains is “often called the 'brain-eating ameba' because it can infect the brain and destroy brain tissue." This happens when water containing the amoeba goes up the nose to the brain, causing an infection called primary amebic meningoencephalitis (PAM).

Health officials in Missouri say a resident has contracted a lab-confirmed case of what is commonly known as "brain-eating" amoeba, and the individual had been at the Lake of the Ozarks before falling ill.