Why Brain Eating Amoeba: Naegleria Fowleri Is Much Deadly?

Why Brain Eating Amoeba: Naegleria Fowleri Is Much Deadly?

Why Brain Eating Amoeba: Naegleria Fowleri Is Much Deadly?


Amoebas are single-celled organisms. The so-called brain-eating amoeba is a species discovered in 1965. It’s formal name is Naegleria fowleri. All subtypes are believed equally dangerous.

Brain-eating amoeba, are extremely rare, but also extremely deadly. Only 146 cases have been reported in the U.S. since 1962, with only four surviving the infection; so there is a 97% chance of death.

How N. Fowleri Gets Into The Brain

fowleridwells in warm bodies of fresh water where it dines on bacteria in the sediment. Diagnosing by most doctors do not ever see this infection in any of their patients. Although the organisms can be found worldwide, mainly in warm waters (lakes, rivers, hot springs, power plant warm water discharge pools) that have loose sediment, are stagnant or contaminated with stirred up bottom sediment, or even in poorly chlorinated swimming pools.

As such, most infections with this amoeba in the U.S. have occurred in southern states, especially Texas and Florida, during the summer. When the sediment of a lake is disrupted, amoeba get stirred into the water. Swimmers can then inhale the parasite through their nose. From there, N. fowleri invades the olfactory nerves and migrates to the brain, where it causes a dangerous condition called primary amoebic meningoencephalitis.

The parasites then migrate to the olfactory nerves (responsible for smell) where they cause nerve cell death. Following the path of the nerve fibers, the parasites cross through the holes in the bone that allow the nerves to enter the brain.

Then the trophozoites simply begin to destroy and consume all types of brain cells (in other words, trophozoites eat the brain). Some trophozoites change forms to become flagellated forms that are rarely, if ever, seen in infected individuals; cyst forms are not seen in infected people.

The brain is moist and warm, just like the lakes and hot springs where the amoeba thrives. But the brain doesn’t have bacteria for the amoeba to eat, so the organism attacks brain cells for nutrients.

The immune system does not sit idly by, however, while the parasite eats its way through the brain. It unleashes a massive swarm of immune cells to the infected zone, which causes inflammation and brain swelling. Unfortunately for the person whose brain is infected, this battle is being waged inside a sturdy skull, which cannot expand to accommodate a swelling brain.

The increase in cranial pressure disrupts the brain’s connection to the spinal cord, compromising communication with other parts of the body like the respiratory system.

Symptoms Of Brain-Eating Amoebas

Symptoms can appear as early as two days, or as late as two weeks, following inhalation of N. fowleri. The first initially symptoms may include:

  • Changes in smell and taste,
  • Headache,
  • Fever,
  • Stiff neck,
  • Nausea, and vomiting.

The patient may have confusion, ataxia (wobbliness), and seizures; and rapidly worsen over about 3 to 7 days with death occurring about 7 to 14 days after exposure. Patients, who are usually young, may not seek medical care quickly; most patients are diagnosed by examination of autopsied brain tissue.

There are several reasons why N. fowleri is so deadly. First, the presence of the parasite leads to rapid and irrevocable destruction of critical brain tissue. Second, the initial symptoms can easily be mistaken for a less serious illness, costing valuable treatment time. Third, there is no quick diagnostic test for N. fowleri, and patients are often mistreated for viral or bacterial meningitis.

Brain Eating Amoeba Prevention Tips

Prevention seems the best way to avoid this rare “brain eating” disease. Abstaining from all water-related activities can prevent Naegleria infections, but for many people, this simply is not an option. There are other things people can do.

  • Avoid swimming in still, warm, brackish water that has loose bottom sediment.
  • Avoid jumping or diving into the same type of water.
  • Wear a nose clip or hold your nose if you jump or dive into relatively warm water lakes, rivers, pools or other similar bodies of water.

Finally, there are no established medications with proven efficacy against the amoeba, although miltefosine is showing promise. Compounding the problem is the fact that most drugs have trouble penetrating the brain and, as primary amoebic meningoencephalitis is a rare disease, very little research is being conducted.

It is important to keep in mind that millions of people are exposed to N. fowleri and never fall ill. Those who study this amoeba don’t know why a tiny subset of exposed individuals develop primary amoebic meningoencephalitis; they may have a genetic difference that makes them more vulnerable to the infection, or may have forcefully inhaled an overwhelming amount of the parasite.

This article on "Hkitnob: Health Columns" is for informational purposes only, and is not meant to offer medical advice.