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Balamuthia Frequently Asked Questions (FAQs)

What is Balamuthia?

Cyst of Balamuthia mandrillaris.

Cyst of Balamuthia mandrillaris. Photo credit: DPDx, CDC

Balamuthia mandrillarisis a free-living ameba (a single-celled living organism) found in the environment. It is one of the causes of granulomatous amebic encephalitis (GAE), a serious infection of the brain and spinal cord[1,2,5,6]. Balamuthia is thought to enter the body when soil containing Balamuthia comes in contact with skin wounds and cuts, or when dust containing Balamuthia is breathed in or gets in the mouth[1,2]. The Balamuthia amebas can then travel to the brain through the blood stream and cause GAE[4]. GAE is a very rare disease that is usually fatal.

Scientists at the Centers for Disease Control and Prevention (CDC) first discovered Balamuthia mandrillaris in 1986. The ameba was found in the brain of a dead mandrill baboon[2,7]. After extensive research, B. mandrillaris was declared a new species of ameba in 1993[7]. Since then, more than 200 cases of Balamuthia infection have been diagnosed worldwide, with at least 70 cases reported in the United States[2]. Little is known at this time about how a person becomes infected[1, 3].

Where is Balamuthia found?

Balamuthia has been found in dust and soil in many places around the world[1, 2, 7]. It is possible that Balamuthia may also live in water.

How do you get a Balamuthia infection and how is it spread?

Balamuthia infection is not spread from person to person.

Balamuthia is thought to enter the body when soil containing Balamuthia comes in contact with skin wounds and cuts, or when dust containing Balamuthia is breathed in or gets in the mouth [1,2]. Once inside the body, the amebas can travel through the blood stream to the brain, where they cause GAE[1,5,6]. There are also a few reports of dogs that might have become infected after swimming in ponds[7].

Balamuthia infection can occur at any time of year[7].

What are the symptoms of a Balamuthia infection[1,5,6]?

Cyst of Balamuthia mandrillaris in brain tissue.

Cyst of Balamuthia mandrillaris in brain tissue. Photo credit: DPDx, CDC

The symptoms of Balamuthia infection can begin with a skin wound on the face, chest, torso, arms, or legs. If the infection involves the brain, the disease it causes is called granulomatous amebic encephalitis (GAE)[5,6]. Diagnosis of Balamuthia GAE can be difficult, but some early symptoms might include:

  • Headaches
  • Stiff neck or head and neck pain with neck movement
  • Sensitivity to light
  • Nausea
  • Vomiting
  • Lethargy (tiredness)
  • Low-grade fever

Other signs of Balamuthia GAE might include:

  • Behavioral changes
  • Seizures
  • Weight loss
  • Partial paralysis
  • Difficulty speaking in full sentences
  • Difficulty walking

The disease might appear mild at first but can become more severe over weeks to several months[6,7]. Often the disease is fatal[7], with a death rate of more than 95%[1]. Overall, the outlook for people who get this disease is poor, although early diagnosis and treatment may increase the chances for survival[1].

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How long after infection do symptoms appear?

It can take weeks to months to develop the first symptoms of Balamuthia GAE after initial exposure to the amebas[1,2].

How long will symptoms last?

GAE is chronic and symptoms develop over a period of several weeks to as long as 2 years. Although Balamuthia GAE is often fatal[2], there are several recorded cases of Balamuthia infection where the patients survived after long-term treatment with multiple drugs[3,6]. In some of those cases, the patients were able to return to normal, functioning lives[1,2].

Who is most likely to get a Balamuthia infection?

Balamuthia can infect anyone; this includes persons that are healthy or persons with weakened immune systems (such as persons with HIV/AIDS, cancer, liver disease, diabetes mellitus and/or persons taking immunosuppressive drugs following organ transplantation)[1,2,5,6].

What should I do if I think I may have a Balamuthia infection?

Contact your health care provider as soon as possible if you think you may have a Balamuthia infection.

How is a Balamuthia infection diagnosed?

Image of a doctor and a patient.

Doctors must use special tests to diagnose Balamuthia, but the CDC is available to help with testing.

Doctors and scientists must use special research tests to identify Balamuthia. These tests are not widely available, but CDC is available to help with testing [1,2,6].

What is the treatment for a Balamuthia infection?

Currently, treatment recommendations include the use of a combination of several drugs. Most cases of Balamuthia are diagnosed right before death or after the patient has died[3,6,7]. This delay in diagnosis limits the amount of experience with different drugs used to treat Balamuthia infection[1]. Current treatment plans are based on lab studies of the ameba and the few cases where the patients have survived.

Should I be worried about getting Balamuthia from others?

No. There have been no reports of a Balamuthia infection spreading from one person to another except through organ donation/transplantation.

How can I prevent a Balamuthia infection?

Currently, there are no known ways to prevent infection with Balamuthia since it is unclear how and why some people become infected while others do not. Research is currently underway to learn more about Balamuthia in hopes of finding ways to prevent future infections.

Is there anything that people with weakened immune systems can do to prevent Balamuthia disease when they landscape, garden, farm, or participate in other activities involving exposure to soil and dust?

Balamuthia can infect anyone, including people who are healthy and people with weakened immune systems. Unfortunately, we are currently unaware of ways to prevent infection with Balamuthia since it is unclear how and why some people become infected while others do not. No one knows exactly what the risk of developing disease from Balamuthia exposure is and what factors contribute to developing disease.

CDC has no specific guidelines for immunosuppressed people to prevent Balamuthia disease. However, immunosuppressed people who want to reduce their risk in general for a variety of infections that might be related to handling soil should consider wearing protective clothing when in contact with soil (such as gloves, shoes, long sleeves, long pants, eye protection) and wash their hands and other exposed skin surfaces with soap and water following soil exposures. Disturbing soil can create clouds of dust particles small enough to be inhaled. Immunosuppressed persons exposed to large amounts of this dust might consider wearing N95 respirators. These respirators fit tightly against the face so that most of the air that is inhaled gets filtered by the mask. There are special requirements for using an N95 respirator at work, so a person thinking about using one should discuss it with their employer or, if self-employed, their doctor. Immunosuppressed persons who are concerned that they might have an infection should seek prompt medical attention.

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This information is not meant to be used for self-diagnosis or as a substitute for consultation with a health care provider. If you have any questions about the parasites described above or think that you may have a parasitic infection, consult a health care provider.

  1. Siddiqui R, Khan NA. Balamuthia amoebic encephalitis: an emerging disease with fatal consequences. Microb Pathog. Feb 2008;44(2):89-97.
  2. Perez MT, Bush LM. Balamuthia mandrillaris amebic encephalitis. Curr Infect Dis Rep. Jul 2007;9(4):323-328.
  3. Schuster FL, Glaser C, Honarmand S, Maguire JH, Visvesvara GS. Balamuthia amebic encephalitis risk, Hispanic Americans. Emerg Infect Dis. Aug 2004;10(8):1510-1512.
  4. Huang ZH, Ferrante A, Carter RF. Serum antibodies to Balamuthia mandrillaris, a free-living amoeba recently demonstrated to cause granulomatous amoebic encephalitis. J Infect Dis. May 1999;179(5):1305-1308.
  5. Maciver SK. The threat from Balamuthia mandrillaris. J Med Microbiol. Jan 2007;56(Pt 1):1-3.
  6. Perez MT, Bush LM. Fatal amebic encephalitis caused by Balamuthia mandrillaris in an immunocompetent host: a clinicopathological review of pathogenic free-living amebae in human hosts. Ann Diagn Pathol. Dec 2007;11(6):440-447.
  7. Visvesvara GS, Moura H, Schuster FL. Pathogenic and opportunistic free-living amoebae: Acanthamoeba spp. , Balamuthia mandrillaris, Naegleria fowleri, and Sappinia diploidea. FEMS Immunol Med Microbiol. Jun 2007;50(1):1-26.
  8. Balamuthia amebic encephalitis--California, 1999-2007. MMWR Morb Mortal Wkly Rep. Jul 18 2008;57(28):768-771.
  9. Schuster FL, Visvesvara GS. Free-living amoebae as opportunistic and non-opportunistic pathogens of humans and animals. Int J Parasitol. Aug 2004;34(9):1001-1027.
  10. Schuster FL, Visvesvara GS. Opportunistic amoebae: challenges in prophylaxis and treatment. Drug Resist Updat. Feb 2004;7(1):41-51.
  11. Martinez DY, Seas C, Bravo F, et al. Successful treatment of Balamuthia mandrillaris amoebic infection with extensive neurological and cutaneous involvement. Clin Infect Dis. Jul 15 2010;51(2):e7-11.
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