Two children in the US have died this month after being attacked by a single-celled organism called Naegleria fowleri, which is typically found in freshwater lakes or ponds and has the capacity to destroy brain cells. It is thought that both children became infected after ingesting contaminated water through their noses while swimming, allowing the deadly amoeba to reach their brains.
Seven-year-old David Pruitt from Tehama County in Northern California was rushed to hospital on July 30, where he tragically died on August 7 despite being placed on life support. Ten days later, a second child – who has not been named – passed away in North Carolina.
According to a statement released by the North Carolina Department of Health and Human Services (NCDHHS), “the child became ill after swimming in a private pond on their residence in central North Carolina in early August.” A subsequent laboratory test carried out by the Centers for Disease Control and Prevention (CDC) revealed that the fatal illness had indeed been caused by N. fowleri.
Often referred to as a brain-eating amoeba, the deadly microorganism is in fact a free-living amoeboflagellate excavate, meaning it has the capacity to shapeshift and possesses one or more whip-like appendages called flagella. It is generally found in warm bodies of freshwater, preferring high temperatures of up to 46 °C (115 °F).
Completely harmless when swallowed, N. fowleri can cause serious damage if it enters the body through the nose. Once it accesses the brain it begins devouring several types of brain cell, including neurons, resulting in a condition called primary amoebic meningoencephalitis (PAM). Unfortunately, PAM is almost always fatal, and there are no effective treatments for the infection.
According to the CDC, PAM is extremely rare, with only 34 cases reported in the US between 2010 and 2019. By comparison, more than 34,000 drowning deaths occurred across the country in the decade leading up to 2010, all of which highlights the fact that N. fowleri does not represent a significant threat to swimmers.
“Hundreds of millions of visits to swimming venues occur each year in the U.S. that result in 0-8 infections per year,” explains the CDC.
“It is unknown why certain persons become infected with the amebae while millions of others exposed to warm recreational fresh waters do not, including those who were swimming with people who became infected.”
This lack of understanding makes it difficult to develop any safety guidelines or public policies to protect swimmers from the brain-eating microbe, although the NCDHHS advises people to try to minimize the amount of water that enters their nose when swimming in rivers or ponds, for example by holding your nose shut and keeping your head above water.