Introduction
You jump into the warm freshwater in your local lake. Water rushes into your nose, throwing you into a coughing fit. After the discomfort has passed, you continue playing in the water, unaware of what may have just invaded your body, a quiet but stealthy parasite…
Commonly found in warm or hot freshwater (such as lakes and rivers, but can rarely be found in poorly maintained waterparks), lives a single-celled parasite called naegleria fowleri, more popularly known as the brain-eating amoeba. It almost sounds like a tiny zombie out of a horror movie, “The Brain-Eating Amoeba” and it is.
Naegleria fowleri infiltrates the body through the nose, traveling up into the brain, causing the disease known as Primary Amebic Meningoencephalitis (PAM). The infection begins to spread throughout the brain, destroying brain tissue, causing swelling, and leading to death if left untreated. The disease is quite rare, having an estimated 147 cases since 1962, but also quite lethal, with 97% of cases resulting in death.
A silent but deadly killer, naegleria fowleri is an underground amoeba that more people should know about.
Our Immune System vs. Naegleria Fowleri
Left untreated, PAM can have irreversible effects on our brain. Some of the earliest symptoms appear as a headache, nausea, vomiting,
and fever. These symptoms slowly progress into confusion, fatigue, seizures, and hallucinations. The mystery of naegleria fowleri is how it manages to invade the innate immune system for several days as it infiltrates through the central nervous system. One hypothesis is that naegleria fowleri is a eukaryotic organism that most immune cell receptors do not recognize as foreign. Overall, the innate immune system is unable to stop naegleria fowleri from reaching the brain.
A big reason for the fatality from PAM is inflammation in the brain. This is a part of the body's immune response towards pathogens but this causes more damage than good as our skull becomes a wall against our brain causing profound brain tissue damage. Thus, research has shown that the best ways to elevate chances of survival are: an early diagnosis with treatment and inducing hypothermia, because it will reduce inflammation.
Currently, there is no one proven treatment for PAM, however, there is a wide variety of treatments and future treatments being tested.
Successful Modern and Future Treatments
According to the CDC (Centers for Disease Control and Prevention), treatments taken by survivors of PAM include: Amphotericin B, Azithromycin, Fluconazole, Rifampin, Miltefosine, Dexamethasone, Phenytoin, and some others listed on their page.
Successful treatment of naegleria fowleri was seen in a case with a 12-year-old female. She was rushed to the emergency department after experiencing a headache, nausea, vomiting, and a fever for the past two days. She was given treatments from the list on the CDC in proper doses. After 24 hours, she’d developed right-sided abducens nerve palsy (an inability to see through her eyes). Two weeks into her illness, an MRI scan showed blood in the frontal lobe and restricted diffusion in different areas of her brain. After nearly two months of treatment, the girl was discharged, and four months later, she can function normally with no issues.
Although PAM is a deadly disease, there is hope for the future as researchers work hard on developing new treatments. A paper published by PLOS Neglected Tropical Diseases explain the testing of around 12,000 compounds to find the most effective compounds against naegleria fowleri. Around 280+ have displayed some effectiveness against the disease, giving hope for higher survival rates in the future.
Conclusion
Naegleria fowleri is a terrifying eukaryotic amoeba, able to dodge our immune system, but is still relatively rare. Please be mindful when swimming in freshwater, especially in bodies of water that seem relatively unclean. Buy goggles with a nose piece as an extra layer of protection and avoid getting water up your nose. If you find yourself with early symptoms of naegleria fowleri (headache, nausea, fever, vomiting) a few days after swimming, do not hesitate to seek medical attention. And remember, stay safe out in the water!
Sources
Moseman, E. Ashley. “Battling Brain-Eating Amoeba: Enigmas Surrounding Immunity to Naegleria Fowleri.” PLOS Pathogens, Public Library of Science, journals.plos.org/plospathogens/article?id=10.1371%2Fjournal.ppat.1008406. Accessed 29 Nov. 2023.
Sanders, Laura. “How ‘brain-Eating’ Amoebas Kill.” Science News Explores, 3 Dec. 2019, www.snexplores.org/article/how-brain-eating-amoebas-kill.
Linam, W Matthew, et al. “Successful Treatment of an Adolescent with Naegleria Fowleri Primary Amebic Meningoencephalitis.” Pediatrics, U.S. National Library of Medicine, Mar. 2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4634363/.
“Treatment | CDC.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 20 Apr. 2023, www.cdc.gov/parasites/naegleria/treatment-hcp.html.
Terry, Mark. “Researchers Synthesize New Brain Eating Amoeba Treatment.” BioSpace, BioSpace, 17 Feb. 2020, www.biospace.com/article/possible-new-drugs-for-brain-eating-amoeba/.
Rice, Christopher A., et al. “Discovery of Repurposing Drug Candidates for the Treatment of Diseases Caused by Pathogenic Free-Living Amoebae.” PLOS Neglected Tropical Diseases, Public Library of Science, journals.plos.org/plosntds/article?id=10.1371%2Fjournal.pntd.0008353. Accessed 29 Nov. 2023.
Assessed and Endorsed by the MedReport Medical Review Board