Brain-Eating Amoeba: Causes, Symptoms, and Treatment

The brain-eating amoeba is scientifically known as Naegleria fowleri - a parasite. This is a very rare parasite and often causes death for people who swim or participate in water sports in freshwater lakes, rivers and hot springs.

What you need to know about Naegleria fowleri (brain-eating amoeba)

The amoeba - called Naegleria fowleri - travels up the nose to the brain and causes severe brain damage. Most people infected with naegleria die within a week of infection.

Millions of people are exposed to the amoeba that causes naegleria infection each year, but only a small number of them become ill. Scientists do not yet understand why some people become infected with naegleria while others do not.

Causes of Brain-Eating Amoeba

Brain-eating amoeba disease is caused by infection with the amoeba Naegleria fowleri, which is commonly found in freshwater lakes around the world. The disease usually occurs in the summer, but the amoeba is also sometimes found in soil.

The amoeba enters your body through your nose when it comes into contact with water or dirt and travels to the infected person's brain through the nerves that transmit the sense of smell.

Not everyone exposed to the amoeba gets sick, and only a small percentage of the millions of people exposed to Naegleria fowleri get sick.

Symptoms of brain-eating amoeba

When a person is infected with the Naegleria amoeba, it causes a disease called Primary amebic meningoencephalitis, which is characterized by inflammation of the brain and destruction of brain tissue. Usually starting two to 15 days after infection, the patient has the following symptoms:

1. Changes in sense of smell or taste
2. Fever
3. Sudden severe headache
4. Stiff neck
5. Sensitive to light
6. Nausea and vomiting
7. Imbalance of the body
8. Often confused
9. Asleep
10. Epileptic
11. Illusion

These symptoms will progress very quickly and cause death within about a week.

Transmission of brain-eating amoeba

The amoeba is not spread from person to person or from an infected person to water. And properly cleaned and disinfected swimming pools should not harbor the naegleria amoeba.

People at risk for brain-eating amoeba disease

In the United States, millions of people are exposed to the amoeba that causes naegleria infection each year, but very few people get sick. From 2007 to 2017, only 40 cases of infection were reported. Some factors that may increase the risk of naegleria infection include:

Swimming in freshwater lakes/ponds/pools . Most people who became ill had swum in freshwater lakes within the previous two weeks.

Amoeba thrives in warm or hot water with the ideal temperature for amoeba being around 35 degrees Celsius. This parasite grows and reproduces more in the summer when the water temperature warms up.

In Vietnam, many people believe that bathing in warm/hot water is good for their health, however, this is also a suitable habitat for brain-eating amoeba to thrive because the water downstream is usually warm.

Children and adolescents are the most susceptible age group , possibly because they spend more time in the water and are more active while underwater, allowing the amoeba time to travel from the nose to the brain.

Prevention of brain-eating amoeba disease

The U.S. Centers for Disease Control and Prevention (CDC) suggests steps to reduce the risk of naegleria infection:

1. Do not swim in or jump into fresh water and warm water lakes.
2. Pinch your nose or use a nose clip when jumping or diving into warm waters.
3. Do not disturb sediments at the bottom of lakes/pools/ponds when swimming in shallow, warm water.
4. Diagnostic measures for brain-eating amoeba

Computed tomography (CT) or magnetic resonance imaging (MRI) scans can show swelling and bleeding in the brain such as:

1. CT scan: In the process of combining X-rays from many different directions to create detailed cross-sectional images of the brain, to see damaged locations.
2. MRI scan:  An MRI machine uses radio waves and a strong magnetic field to create extremely detailed images of soft tissues such as the brain.
3. Lumbar puncture: Naegleria amoeba can be seen under a microscope using a lumbar puncture technique. The doctor will aspirate cerebrospinal fluid at the L2-S2 vertebrae, during the aspiration the doctor will also measure cerebrospinal fluid pressure to assess whether the patient has increased intracranial pressure.

Treatment of Brain-Eating Amoeba

Very few people survive naegleria infection even with treatment. Early detection, diagnosis, and treatment are critical to survival.

The main treatment for naegleria infection is antifungal medication , amphotericin B, given intravenously or injected into the area around the person's spinal cord to kill the amoeba.

An experimental drug called miltefosine is used as an emergency treatment for naegleria infections. When used with other drugs and combined with control of brain swelling, it may increase survival.