Granulomatous Amebic Encephalitis or GAE

Granulomatous Amebic Encephalitis or GAE is a severe infection in the brain and spinal cord. It is a life-threatening infection. It is caused by free-living amoebae known as Acanthamoeba, sappinia pedara and balamuthia. Balamuthia mandrillaris causes a rare infection in granulomatous amebic encephalitis. The spread of these protozoa can affect the skin, lungs, sinuses and other organs in the body. It occurs when a person has a compromised immune system. GAE mortality rate is high.

The disease is due to Acanthamoeba that is related to living amoeba and encephalitis. Acanthamoeba is a free-living ameba or a single-cell living organism that can create rare but severe infections in the central nervous system. The ameba can be found in the water and soil, and may be spread in the eyes through cuts or skin wounds, or are being inhaled in the lungs. Most people are exposed to Acanthamoeba in their lifetime, but only a few of them become sick. Acanthamoeba can survive in heat, water, body fluids and tissue cultures.

The mode of infection of granulomatous amebic encephalitis is from the nasal and lower respiratory tract to the blood and then the brain. It may also occur from ulcerated skin and mucosa to the blood and brain.


There are three kinds of diseases caused by Acanthamoeba. One of this is Granulomatous Amebic Encephalitis that cause a severe infection in the brain and spinal cord in people with compromised immune systems.

Acanthamoeba keratitis is an infection in the eye that occurs in a healthy person and can cause visual problems.

Disseminated infection is a widespread infection that can affect the skin, lungs, and sinuses.


  •  Change in mental status
  •  Muscular weakness
  • Fever
  • Paralysis in one side of the body
  • Sensitivity to light
  • Double vision
  • Neurologic problems
  • Seizures
  • Headaches
  • Problems when speaking

Symptoms depend on the part of the brain that is being affected by the infection.


Diagnosis is difficult to understand and is usually made in the advanced stage.

A brain biopsy will identify the presence of lesions caused by amoeba.

Imaging tests and a spinal tap can help rule out other causes. When there is a skin sore, a sample is taken and is studied under microscope to find the ameba. Skin biopsy and magnetic resonance imaging will also help in the diagnosis.



Granulomatous Amebic Encephalitis or GAE and skin sores are treated with these drugs:

  •  Pentamidine, an anti fungal drug
  •  Sulfadiazine, an antibiotic
  •  Flucytosine, an anti fungal drug
  •  Azithromycin, an antibiotics
  •  Amphotericin B, an anti fungal drug

A combination of medical and surgical is required to prevent death.

Even when there’s treatment, Acanthamoeba is fatal and there are only a few reports about people who survived; almost all of them suffered permanent neurocognitive deficiency.

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