Skip all navigation Skip to page navigation

DHHS Home | A-Z Site Map | Divisions | About Us | Contacts

NC Department of Health and Human Services
NC Division of Public Health
N.C. Public Health Home

Diseases & Topics

Primary Amebic Meningoencephalitis

Naegleria fowleri (commonly referred to as the "brain-eating amoeba" or "brain-eating ameba"), is a free-living microscopic ameba, (single-celled living organism). It can cause a rare and devastating infection of the brain called primary amebic meningoencephalitis (PAM).

The ameba is commonly found in warm freshwater (e.g. lakes, rivers, and hot springs) and soil. Naegleria fowleri usually infects people when contaminated water enters the body through the nose. Once the ameba enters the nose, it travels to the brain where it causes PAM, which is usually fatal.

Infection typically occurs when people go swimming or diving in warm freshwater places, like lakes and rivers. In very rare instances, Naegleria infections may also occur when contaminated water from other sources (such as inadequately chlorinated swimming pool water or heated and contaminated tap water) enters the nose, for example when people submerge their heads or cleanse their noses during religious practices, and when people irrigate their sinuses (nose) using contaminated tap water. 

You cannot get infected from swallowing water contaminated with Naegleria.

Naegleria fowleri infections are rare. In the 10 years from 2006 to 2015, 37 infections were reported in the U.S. Of those cases, 33 people were infected by contaminated recreational water, 3 people were infected after performing nasal irrigation using contaminated tap water, and 1 person was infected by contaminated tap water used on a backyard slip-n-slide.

Personal actions to reduce the risk of Naegleria fowleri infection should focus on limiting the amount of water going up the nose. These actions could include:

  • Holding your nose or using nose clips when taking part in water-related activities;
  • Avoiding putting your head underwater in hot springs and other warm fresh water bodies;
  • Avoiding water-related activities in all warm freshwater bodies during periods of high water temperature; and
  • Avoiding digging in, or stirring up mud and scum while taking part in water-related activities in shallow, warm freshwater areas.

These prevention recommendations make common sense but are not based on any scientific testing, since the low number of infections makes it difficult to ever test whether they are effective.

Testing for Naegleria fowleri infection involves obtaining spinal fluid. CDC does not recommend testing for people without symptoms. For diagnostic assistance, specimen collection guidance, specimen shipping instructions, and treatment recommendations, clinicians should contact the CDC Emergency Operations Center at 770-488-7100.

For Additional Information