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The Spread of Brain-Eating Amoeba

By Leyla Urmanova

November 18, 2022


[Photo credit: IFL Science]

Imagine swimming in a warm freshwater lake only to learn that a deadly microorganism is lurking nearby. Naeglari Fowleri, or brain amoeba, is a species that can inflict serious damage on the human body. First identified in Australia, N. Fowleri has already spread to the United States and is able to survive in temperatures as high as 115 degrees.

Despite its classification as a single-celled organism, the N. Fowleri’s impact on physical health is severe. Once inside the human body, this particular amoeba can cause primary amebic meningoencephalitis (PAM), a brain infection that results in the destruction of brain tissue. According to the Center of Disease Control (CDC), The symptoms of PAM can range from vomiting and fever to loss of balance and seizures – growing in severity as the disease progresses. Often, PAM leads to human death in less than a week due to the increased swelling of brain tissue caused by infection. As for the reported fatality rate of this disease, it is at an overwhelming 98%; only four individuals have been known to survive it in the U.S.

After zooming closer into the brain-eating process, researchers found N. Fowleri amoebas are drawn to the brain chemicals that are secreted by cells of the olfactory nerve, which helps determine our sense of smell. Since the amoeba is microscopic and found in warm water, it is commonly known for entering through the nose. Then, once it travels through the olfactory nerve and locates the frontal lobe of the brain (the part mainly responsible for decision-making and planning), it is given the leeway to destroy surrounding nervous tissue.

N. Fowleri can be located in areas consisting of contaminated warm freshwater, including hot springs, un-chlorinated swimming pools, and slow-moving rivers. As a thermophilic organism, this species thrives in heated environments and is more likely to infect people during times of warm climate. In the United States, N. Fowleri is also more prevalent in southern states than northern ones – though it is unable to survive in saltwater.

Charles Gerba, a microbiologist at the University of Arizona, observes that climate change is leading to the facilitation and growth of this brain-eating amoeba. He warns that rising global temperatures are enabling the pathogen to migrate to midwestern territories. Additionally, since the current climate crisis is causing an increase in floods and droughts, which can lead to the pathogen’s greater exposure to the environment. Therefore, because of the current trends in climate, people residing in colder regions may soon find themselves facing the risk of contracting PAM. Due to a lack of identification and treatment methods for this pathogen, people can expect to see a growth in its prevalence.


“Brain-Eating Amoeba: What to Know.” WebMD, WebMD,

“General Information.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 8 July 2022,

“How the Climate Crisis Is Fueling the Spread of a Brain-Eating Amoeba.” The Guardian, Guardian News and Media, 21 Sept. 2022,

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