What is Balamuthia?

Balamuthia mandrillaris is a free-living ameba (a single-celled living organism) found in the environment. It is one of the causes of a serious infection of the brain called granulomatous amebic encephalitis (GAE). GAE is a very rare disease that is usually fatal.

CDC first discovered Balamuthia mandrillaris in 1986. The ameba was found in the brain of a dead mandrill (a type of primate). After extensive research, B. mandrillaris was determined to be a new species of ameba in 1993. Since then, more than 200 cases of Balamuthia infection have been diagnosed worldwide, with over 100 cases reported in the United States.

Where is Balamuthia found?

Balamuthia has been found in dust and soil in many places around the world. Balamuthia has also been found 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 into the lungs. Once inside the body, the amebas can travel through the blood stream to the brain, where they cause GAE.

Balamuthia infection can occur at any time of year.

What are the symptoms of a Balamuthia infection?

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). Diagnosis of Balamuthia GAE can be difficult because symptoms are not specific to GAE. Early symptoms might include:

• Fever
• Headache
• Vomiting
• Lethargy
• Nausea

Other signs of Balamuthia GAE might include:

• Mental health changes
• Seizures
• Weakness
• Confusion
• Partial paralysis
• Difficulty speaking
• Difficulty walking

The disease might appear mild at first but can become more severe over weeks to several months. Often the disease is fatal, with a death rate of 90%. Overall, the outlook for people who get this disease is poor, although early diagnosis and treatment may increase the chances for survival.

How long after infection do symptoms appear?

The length of time from infection to the time symptoms appear is unknown. It can take weeks to months to develop the first symptoms of Balamuthia GAE after initial exposure to the amebas.

How long will symptoms last?

The duration of symptoms for GAE is highly variable with some people being sick for just a few days and some having symptoms for weeks or months. Although Balamuthia GAE is often fatal, there are several recorded cases of Balamuthia infection where the patients survived after long-term treatment with multiple drugs. In some of those cases, the patients were able to return to normal, functioning lives.

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, persons taking immunosuppressive drugs, and people who have had organ transplantation).

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

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

How is a Balamuthia infection diagnosed?

Doctors and scientists must use special tests to identify Balamuthia. These tests are not widely available, but CDC is available to help with testing.

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. This delay in diagnosis limits the amount of experience doctors have using different drugs to treat Balamuthia infection. 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. Surveillance for Balamuthia infections continues so that CDC can learn more about Balamuthia in hopes of finding ways to prevent future infections.

Balamuthia infection is a rare and usually fatal disease. Since Balamuthia was first discovered in 1986, about 200 cases of infection have been reported worldwide. This number includes over 100 confirmed cases in the United States. Because disease caused by Balamuthia is so uncommon, it is possible that there have been additional cases that were misdiagnosed.

Balamuthia amebas (single-celled living organisms) are thought to enter the body when soil containing Balamuthia comes in contact with skin wounds and cuts, or when dust containing Balamuthia is breathed into the lungs . Once inside the body, the amebas can then travel to the brain and cause granulomatous amebic encephalitis (GAE). GAE is a severe disease of the brain that is fatal in 90% of cases. It can take weeks to months to develop the first symptoms of Balamuthia GAE after initial exposure to the amebas.

Balamuthia amebas live freely in soil around the world. Gardening, playing with dirt, or breathing in soil carried by the wind might increase the risk for infection . Balamuthia might also be present in fresh water.

The Balamuthia ameba is able to infect anyone, including healthy people. Among Balamuthia cases in the United States with a reported immunocompromising condition, these included:

• Diabetes
• HIV/AIDS
• Solid organ transplant
• Taking an immunosuppressive drug
• Liver cirrhosis
• Renal failure
• Cancer

In the United States, Balamuthia infection is more common among Hispanic Americans. However, the cause of this trend is unknown and might be due to differences in exposure, biology, data collection, or other reasons. More research is needed to understand what factors might be associated with increased reporting among persons of Hispanic ethnicity.

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

Balamuthia infection is a rare and serious illness. The Balamuthia amebas can infect the skin, brain and other organs of the body. Therefore, Balamuthia infection can cause a wide range of symptoms. Disease can begin with a skin wound on the face, trunk, or limbs and can then progress to the brain where it causes a disease called granulomatous amebic encephalitis (GAE).

Diagnosis of Balamuthia GAE can be difficult because symptoms are not specific to GAE. Early symptoms might include:

• Fever
• Headache
• Vomiting
• Lethargy
• Nausea

Other signs of Balamuthia GAE might include:

• Mental health changes
• Seizures
• Weakness
• Confusion
• Partial paralysis
• Difficulty speaking
• Difficulty walking

The disease might appear mild at first but can become more severe over weeks to several months. Often the disease is fatal, with a 90% death rate. Overall, the outlook for people who get this disease is poor, although early diagnosis and treatment may increase the chances for survival.

Balamuthia granulomatous amebic encephalitis (GAE) is a serious infection of the brain caused by Balamuthia. GAE is often diagnosed only after death. However, it can be diagnosed by examining tissue samples from a living patient as well. Diagnosis of GAE in a living patient is less common because the amebas are difficult to identify under the microscope, even with commonly used stains.

However, there are three types of tests that can help confirm the diagnosis of GAE. The indirect immunofluorescence assay (IFA) is a test used to detect antibodies developed against Balamuthia amebas in the serum of infected patients. In contrast, immunohistochemistry (IHC) and indirect immunofluorescence (IIF) staining use specific antibodies against Balamuthia to detect the amebas. Finally, a polymerase chain reaction (PCR) molecular assay can detect Balamuthia DNA, especially in brain tissues .

CDC offers diagnostic assistance for Balamuthia to physicians and scientists through DPDx and the Free-living and Intestinal Amebas (FLIA) laboratory. Morphology experts at DPDx can evaluate microscopic images, while the scientists at the FLIA laboratory provide diagnostic assistance using molecular and immunofluorescence assays.

Although there have been more than 200 cases of Balamuthia infection worldwide, few patients are known to have survived as a result of successful drug treatment. Early diagnosis and treatment might increase the chances for survival.

Drugs used in treating granulomatous amebic encephalitis (GAE) caused by Balamuthia have included a combination of flucytosine, pentamidine, fluconazole, sulfadiazine and either azithromycin or clarithromycin. Recently, miltefosine in combination with some of these other drugs has shown some promise. Much more information is needed in treating patients with GAE due to Balamuthia.

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.

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