Brain-eating amoeba

Brain-eating amoeba


  • A 15-year-old boy in Kerala’s Alappuzha district has died due to a rare infection caused by Naegleria fowleri or “brain-eating amoeba” after a week of high fever and rapid deterioration in his vitals.
  • He used to take a bath in a stream near his home, the likely source of the amoeba, which is known to thrive in any natural environment, particularly in warm water habitats.
  • However, it doesn’t survive in saline conditions and is hence not found in sea water.
  • It survives on bacteria found in the sediment in lakes and rivers.

What is Naegleria fowleri?

  • Naegleria fowleri, commonly known as “brain-eating amoeba,” is a single-cell organism found in a warm freshwater environment such as lakes, hot springs and even in poorly maintained swimming pools.
  • It is so small that it can only be seen with a microscope.
  • Only one species of Naegleria, Naegleria fowleri, infects people.
  • In very rare instances, Naegleria fowleri has been found in swimming pools, splash pads, surf parks, or other recreational venues that are poorly maintained or don’t have enough chlorine in them.
  • The amoeba enters the body through the nose and travels to the brain, leading to a severe and usually fatal brain infection known as primary amebic meningoencephalitis (PAM).
  • Although the amoeba becomes vulnerable in its maturing or trophozoite phase, as a cyst it becomes resistant to its environment.
  • It grows best at temperatures above 46 degree celsius. Although trophozoites are killed rapidly by refrigeration, cysts can survive even extreme cold.
  • Warm water temperatures, particularly during the summer months, create favourable conditions for the amoeba’s growth.
  • Poorly maintained swimming pools or contaminated water sources increase the risk of exposure.
  • Activities like diving or jumping into warm freshwater bodies can force water up the nose, providing an entry point for the amoeba.

How does it spread in the human body?

  • It is typically acquired through the nasal passage and mouth when a person goes swimming, diving, or even uses contaminated water for religious rituals.
  • The amoeba then migrates through the olfactory nerve to the brain, where it causes severe inflammation and destruction of brain tissue.

Can it also spread from one person to another?

  • It’s important to note that Naegleria fowleri infection does not spread from person to person, nor does it manifest symptoms when contracted in other forms.
  • The infection is primarily associated with a warm freshwater environment, especially during hot summer months when water temperatures are higher.
  • Therefore, they usually flourish between July and September.

What prevention measures should a swimmer consider? 

  • Preventive measures such as avoiding warm freshwater bodies with inadequate chlorination, using nose clips during water-related activities, and using sterile water for nasal cleansing rituals can help reduce the risk of contracting Naegleria fowleri infection.

Who is at risk of getting infected?

  • Although anyone can be affected, certain factors can increase vulnerability, such as a weakened immune system, a history of nasal or sinus issues, or activities that involve exposure to warm freshwater. 

What about treatment?

  • The US-based Centers for Disease Control (CDC) recommends treatment with a combination of drugs, often including amphotericin B, azithromycin, fluconazole, rifampin, miltefosine, and dexamethasone.
  • These drugs have been used to treat patients who survived.
  • Miltefosine is the newest of these drugs. It has been shown to kill Naegleria fowleri in the laboratory and has been used to treat three survivors.

What preventive measures can be taken to manage natural water bodies?

  • Limit activities in warm fresh water bodies such as lakes, hot springs and ponds unless they are disinfected with chlorine.
  • Use nose protection while swimming or diving, maintain clean swimming pools, follow proper hygiene, washing your hands thoroughly with soap and water before and after water activities, as well as before eating.
  • Use sterile water for nasal cleaning.

Syllabus: Prelims