Infection with the naegleria amoeba is usually confirmed through a laboratory test of cerebrospinal fluid (CSF), the fluid that surrounds the brain and spinal cord.

To get a sample of CSF, a doctor performs a spinal tap (lumbar puncture). During this procedure, a needle is inserted between two vertebrae in the lower back. A small amount of CSF is removed and sent to a lab, where it is examined under a microscope to determine whether the naegleria amoeba is present. A spinal tap can also be used to measure the cerebrospinal fluid pressure and look for inflammatory cells.

Imaging tests

A doctor may order imaging tests, such as computerized tomography (CT) or magnetic resonance imaging (MRI) to reveal swelling and bleeding within the brain.

  • CT scan. This procedure combines X-ray views taken from many different directions into detailed cross-sectional images.
  • MRI. An MRI machine uses radio waves and a strong magnetic field to produce extremely detailed images of soft tissues, such as the brain.


Few people survive naegleria infection, even with treatment. Early diagnosis and treatment are crucial for survival.

The recommended treatment for naegleria infection is a combination of drugs, including:

  • Amphotericin B, an antifungal drug that is usually injected into a vein (intravenously) or into the space around the spinal cord to kill the amoebas.
  • Miltefosine (Impavido), an investigational drug that is usually used to treat breast cancer and leishmaniasis but has also shown promise against the naegleria amoeba in laboratory and animal studies. It has also been used to successfully treat infections with other types of amoebas.
  • Other antifungal drugs.
  • Antibiotics.

In addition to these drugs, your doctor may recommend other medications or treatment options to manage or decrease brain swelling.

Preparing for your appointment

If you believe you or your child may have naegleria infection, seek immediate medical attention. You might want to make a list of answers to the following questions:

  • What are the signs and symptoms?
  • When did they start?
  • Does anything make them better or worse?
  • Has the person been swimming in fresh water within the past two weeks?
Nov. 07, 2020
  1. Parasites — Naegleria fowleri — Primary amebic meningoencephalitis (PAM) — Amebic encephalitis. Centers for Disease Control and Prevention. https://www.cdc.gov/parasites/naegleria/. Accessed Oct. 14, 2020.
  2. Seas C, et al. Free-living amebas and prototheca. https://www.uptodate.com/contents/search. Accessed Oct. 14, 2020.
  3. Kliegman RM, et al. Primary amebic meningoencephalitis. In: Nelson Textbook of Pediatrics. 21st ed. Elsevier; 2020. https://www.clinicalkey.com. Accessed Oct. 14, 2020.
  4. Bellini NK, et al. The therapeutic strategies against Naegleria fowleri. Experimental Parasitology. 2018; doi:10.1016/j.exppara.2018.02.010.


Associated Procedures

Products & Services