Water School

What is primary amebic meningoencephalitis (PAM)?

Primary Amebic Meningoencephalitis, or PAM, is a disease caused by the ameba Naegleria fowleri. It infects humans when water containing this ameba enters the body through the nostrils, according to the Texas Department of State Health Services

The infected water travels to the brain through the nose, destroying brain tissue. While rare, PAM affects 1 to 3 people in the U.S. every year, according to the Centers for Disease Control and Prevention. PAM is usually fatal. Early symptoms of PAM are very similar to those of bacterial meningitis, including headache, vomiting, nausea, and fever. 

The amoeba that causes PAM thrives in freshwater and soil. Infections typically occur when water temperatures are above 80 degrees and water levels are low.

The most common months of infection in Texas are the summer months of July, August, and September.

To prevent infection, those planning to take part in water-related activities should take these suggestions into consideration:

  • Use nose clips or pinch your nose closed if you plan to submerge your head in warm freshwater such as lakes, rivers, and hot springs. 
  • If water levels are low and freshwater temperatures are higher than 80 degrees, avoid water-related activities in bodies of warm freshwater.
  • Avoid agitating the lake bottom (sediment) in areas of warm and shallow freshwater.
  • When doing a sinus flush or nasal irrigation, use only sterile, distilled, or previously boiled and cooled water.

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The information provided on this site is intended as background on water within the Brazos River basin. There should be no expectation that this information is all encompassing, complete or in any way examines every aspect of this very complex natural resource.

If you have questions about a post or would like additional information, please contact us or call 888-922-6272.

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