Climate Change Creates Favorable Conditions for Brain-Eating Amoeba

Naegleria fowleri is a rare and dangerous single-cell organism that typically lives in freshwater or soil — specifically, warm water or soil. So as temperatures climb around the world due to climate change, the deadly Naegleria fowleri can spread in locations it isn’t normally found.

As explained by the Centers for Disease Control and Prevention, Naegleria fowleri can contaminate warm freshwater. Then, as people go swimming in infected waters, the Naegleria fowleri, also known as brain-eating amoeba, enters through the nose, travels upward and begins destroying brain tissue. The amoeba causes a disease called primary amebic meningoencephalitis (PAM), which is rare but highly lethal.

The Naegleria fowleri grows in warm waters, above 80°F, and thrives in temperatures up to 115°F. So in the U.S., it has usually been an issue in southern states or in northern states during the summer. But as climate change causes an increase in temperatures across the country, Naegleria fowleri has more opportunities to spread. 

It has been found as far north as Minnesota, and a child died from Naegleria fowleri in Nebraska last month. The brain-eating amoeba was also confirmed in the Lake of Three Fires in Iowa this summer and caused another death.

Naegleria fowleri infections often occur after someone swam in a freshwater source, such as a lake or river. But the amoeba may also contaminate naturally warm waters, like in hot springs, or can spread in poorly maintained pools. Some cases have also been linked to nasal irrigation.

Yun Shen, an environmental engineer at the University of California Riverside, told The Guardian that climate change can also make matters worse by increasing the frequency of extreme events, such as flooding or drought. These events can introduce more pathogens into the environment.

“In the drought areas, the pathogens will be concentrated in the water bodies, which could increase the exposure dose of pathogens when humans are in close contact with the water bodies,” Shen explained.

With flood events, flood waters can move pathogens from other bodies of water or the soil into buildings.

“In the future, due to climate change, people living in cold regions might also be exposed to warmer weather and higher chances of being exposed to pathogens,” Shen added.

According to the Iowa Environment Council, there is always a low risk of infection during recreational activities in freshwater, but there are some precautions to help protect oneself, including 1) avoiding stirring sediment at the base of the water source; 2) keeping the head out of the water; 3) wearing nose clips or holding the nose before becoming submerged; and 4) avoiding freshwater when temperatures are high, which may be harder to do with temperatures increasing more and more.

“As the temperature of surface waters increases further north, we expect more cases in the future,” Charles Gerba, a microbiologist at the University of Arizona, told The Guardian. “I would expect this trend to continue.”