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Brain-Eating Amoeba : Symptoms, Diagnosis, Cure and Prevention

Verified By Apollo General Physician April 10, 2023 7235 0
Brain-Eating Amoeba
Brain-Eating Amoeba


If you are one of those students who paid attention in biology classes in school, you would know that there is a single-celled organism called an amoeba. But do you also know a species of amoeba known as the brain-eating amoeba? Only a few know about it. It was first identified in 1965 in Australia and is scientifically called Naegleria fowleri.

This blog is a comprehensive guide on the effect it can create on the human body, its symptoms, and treatment options. 

What is a Brain-Eating Amoeba?

Brain-eating amoeba is a type of amoeba that typically hides out in warm freshwater areas or dirty, untreated waters. When it enters the human body, it creates a lethal infection and inflammation in the brain, ultimately resulting in brain tissue’s ‘eating’ away. The medical term for this condition is primary amoebic meningoencephalitis (PAM). You can contract this condition only when contaminated water carrying the brain-eating amoeba enters your nose. Naegleria comes in various species, but only the fowleri species causes PAM. 

Depending on its life stage and habitat, N. fowleri ranges in size from 8 micrometers to 15 micrometers. Naegleria reproduces by cell division, just like other amoebas do. The amoebas develop into dormant cysts when the circumstances are unfavorable. When conditions are right, the cysts develop into trophozoites, the amoeba’s feeding form.

Where Can You Find Brain-Eating Amoebas?

Untreated, warm water is the perfect environment for brain-eating amoeba. It is an ideal habitat for naegleria. It can live at a temperature of 115 degrees F in warm water without dying. The following are some of the places they are found:

  • Warm ponds, lakes, and rock formations
  • Mud holes
  • Rivers with warm currents, particularly those with low water levels
  • Spas and swimming pools where water is not treated
  • Untreated municipal water supply or well water
  • Various geothermal water sources, including hot springs
  • Thermally contaminated water, such as aquarium runoff from power plants
  • Water play areas for kids
  • Aquatic parks

Naegleria cannot survive in adequately treated municipal water, swimming pools, or salt water.

What are the First Symptoms of PAM?

PAM does not have specific symptoms. It may first resemble viral meningitis. The signs include

You could also experience hallucinations, drooping eyelids, blurred visions, and a loss of taste.

How Does the Brain-Eating Amoeba Infect People?

According to experts, N. fowleri typically feeds on bacteria. But, once they enter people, the amoeba feeds on the brain. Since the nose serves as the pathway for the amoeba to enter you, infections are most frequently brought on by activities that force water up the nose, like diving, water skiing, and other water sports. Nonetheless, infections have happened in persons who have dipped their heads in hot springs or cleaned their nostrils with untreated tap water. N. fowleri infections do not spread from one person to another.

How Often Do Individuals Contract a Brain-Eating Amoeba?

Although N. fowleri amoeba is relatively abundant, they rarely cause brain damage. Studies have proven the presence of antibodies in many people, implying that those who contracted the amoeba could fight it off, thanks to their immune systems.

Researchers are still unsure if N. fowleri invariably results in PAM or only occasionally results in PAM. But their research suggests that exposure to the amoeba is substantially more widespread than the incidence of PAM.

How Is Brain-Eating Amoeba Infection Diagnosed?

It can be challenging to identify brain-eating amoeba infection. If your doctor suspects PAM, they will run lab tests to check for amoeba samples in your cerebrospinal fluid, biopsies, or tissue samples. 

Is There a Cure for Brain-Eating Amoeba Infection?

Amphotericin B is the treatment of choice for primary amoebic meningoencephalitis (PAM) or infection with a brain-eating amoeba. It is noted that a few survivors in North America were treated by their doctors with a combination of several medications, including amphotericin B, rifampin, fluconazole, and miltefosine – a medicine approved for a parasitic disease due to sandflies. 

However, as noticed with two children who recovered completely, the doctors got the best results from early diagnosis and treatment with the recommended drugs. The treatment also includes cooling the body to below-normal temperature to treat brain swelling.

Can Water Be Tested to check the Presence of Brain-Eating Amoeba?

Yes. To check for N. fowleri, experts can gather water samples from a lake or a pool, concentrate them, and cultivate them in a lab. The samples can then be subjected to specific laboratory tests to detect the amoeba.

Are Some Groups More Prone to PAM Than Others?

Children aged 13 or younger and adult males are reported to have been affected more by this condition. It may be because people from these groups participate more in activities that expose them to the amoeba.

How to Prevent Infection from Brain-eating Amoeba?

You can prevent infection from brain-eating amoeba when you:

  1. Avoid swimming, wading, or performing water sports in warm freshwater, particularly still waters, without nose plugs. Avoid entering the water if you know or suspect Naegleria fowleri presence. 
  2. Prevent using tap water for the neti pot or any other devices to clean your nasal passages. It is recommended to use only distilled or sterilized water. But if you cannot find sterilized or distilled water, boil tap water for a minute and cool it down before using it. If you reside in a region above 6,500 feet above sea level, boil the water for three minutes. Let it cool down before using it.
  3. Use filers labeled ‘NSF 53,’ ‘NSF 58,’ or ‘absolute pore size of 1 micron or smaller’ to eliminate germs from the water. 
  4. If you want to disinfect your water with chlorine bleach liquid or a tablet to clean your nasal passage, choose products that are made for your needs. Chlorine bleach liquid or a tablet are different for drinking and cleaning your nose. 
  5. In case you develop a fever or headaches after being in warm freshwater, immediately inform your doctor. 


Learning about a disorder brought on by a dangerous brain-eating amoeba is essential. But, early diagnosis may help you defeat the condition. If you believe you have been exposed to untreated warm water, seek emergency medical attention to confirm you are safe. 


Frequently Asked Questions (FAQs)

How Soon Will the Symptoms of PAM Show Up?

After N. fowleri amoeba enters the nose, symptoms may take two to fifteen days to show up. In most cases, the patient passes away in 3 to 7 days following the onset of symptoms. 

Is There a Rapid Test for a Brain-Eating Amoeba Infection?

There is no rapid test to diagnose a brain-eating amoeba infection. However, scientists are trying to create rapid tests for diagnosis. 

Verified By Apollo General Physician
Our expert general medicine specialists verify the clinical accuracy of the content to deliver the most trusted source of information, making the management of health an empowering experience.

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