Naegleria fowleri Infection
Mary D. Nettleman, MD, MS, MACP
Jeremy Cauwels, MD, FACP
Charles Patrick Davis, MD, PhD
Naegleria fowleri infection facts
- Naegleria fowleri is an amoeba that lives predominately in warm freshwater.
- Naegleria fowleri is acquired by people when infected water is forcibly aspirated into the nose. This can occur through recreational swimming, diving, or during sports like water skiing.
- Once acquired, the amoeba travels into the brain, causing primary amoebic meningoencephalitis (PAM).
- PAM is very rare, and there are only a few cases reported each year in the United States.
- People with PAM have a rapidly progressive illness with fever, headache, and stiff neck, and finally coma and death.
- Infection is diagnosed by examining spinal fluid under the microscope to identify the amoeba. Naegleria fowleri may also be grown in the laboratory, although this takes several days. Newer tests based on PCR technology have been developed but are not widely available.
- The treatment of choice is an intravenous drug called amphotericin B. Amphotericin B may also be instilled directly into the brain. Because treatment with amphotericin B alone usually fails, other drugs are often added. Miltefosine is a drug that has shown promise, and it is available through the Centers for Disease Control and Prevention. Treatment should be initiated as rapidly as possible, and immediate consultation with an infectious-diseases expert is highly recommended.
- More than 99% of cases of PAM are fatal despite treatment.