Diagnosis and Detection

Clinicians: For 24/7 diagnostic assistance, specimen collection guidance, shipping instructions, and treatment recommendations, please contact the CDC Emergency Operations Center at 770-488-7100.

For more information on the appearance of Naegleria fowleri, visit the Photos page.

Primary amebic meningoencephalitis (PAM) is a serious brain infection caused by Naegleria fowleri. The disease is diagnosed using laboratory tests, but these tests are available in only a few laboratories in the United States. Because the infection is so rare and hard to detect at first, diagnosis sometimes happens after the patient’s death.

PAM can be diagnosed in the laboratory by detecting Naegleria fowleri organisms, nucleic acid, or antigens in a patient’s cerebrospinal fluid (CSF) or brain tissue.

Healthcare providers, laboratory personnel, and public health practitioners: Find more information about the detection and diagnosis of Naegleria fowleri, including CDC specimen submission instructions.


  1. Marciano-Cabral F, Cabral G. The immune response to Naegleria fowleri amebae and pathogenesis of infection. FEMS Immunol Med Microbiol. 2007;51:243-59.
  2. Visvesvara GS. Free-living amebae as opportunistic agents of human disease.J Neuroparasitol. 2010;1.