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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.

CDC no longer provides miltefosine for treatment of free-living ameba infections. Miltefosine is now commercially available. Please visit impavido.com for more information on obtaining miltefosine in the United States. If you have a patient with suspected free-living ameba infection, please contact the CDC Emergency Operations Center at 770-488-7100 to consult with a CDC expert.

Although most cases of primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri infection in the United States have been fatal (153/157 in the United States1), there have been five well-documented survivors in North America: one from the United States in 1978 2,3, one from Mexico in 2003 4, two from the United States in 2013 5,6, and one from the United States in 2016. It has been suggested that the original U.S. survivor’s strain of Naegleria fowleri was less virulent, which contributed to the patient’s recovery. In laboratory experiments, the original U.S. PAM survivor’s strain did not cause damage to cells as rapidly, suggesting that it was less virulent than strains recovered from other fatal infections 7. Multiple other patients have received treatments similar to the original U.S. PAM survivor, including amphotericin B, miconazole/fluconazole/ketoconazole, and/or rifampin. They did not survive, making it difficult to determine the efficacy of the treatment regimen.

After 35 years without a Naegleria survivor in the United States, during the summer of 2013, two children with Naegleria fowleri infection survived. The first, a 12-year-old girl, was diagnosed with PAM approximately 30 hours after becoming ill and was started on the recommended treatment within 36 hours. She also received the investigational drug miltefosine, and her cerebral edema and elevated intracranial pressure were aggressively managed with interventions that included therapeutic hypothermia. This patient made a full neurologic recovery and returned to school. Her recovery has been attributed to early diagnosis and treatment and novel therapeutics including miltefosine and hypothermia 5.

The second child, an 8-year-old male, is also considered a PAM survivor, although he has suffered what is likely permanent brain damage. He was also treated with miltefosine but was diagnosed and treated several days after his symptoms began. Therapeutic hypothermia was not used in this case 6.

In the summer of 2016, a 16-year-old boy was reported as the fourth U.S. PAM survivor. This patient was diagnosed within hours of presentation to the hospital and was treated with the same protocol used for the 12-year-old 2013 survivor. This patient also made a full neurologic recovery and returned to school.

Clinical and Laboratory Information

  1. Yoder JS, Eddy BA, Visvesvara GS, Capewell L, Beach MJ. The epidemiology of primary amoebic meningoencephalitis in the USA, 1962-2008. Epidemiol Infect. 2010;138:968-75.
  2. Seidel JS, Harmatz P, Visvesvara GS, Cohen A, Edwards J, Turner J. Successful treatment of primary amebic meningoencephalitis. N Engl J Med. 1982;306:346-8.
  3. 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. 2007;50:1-26.
  4. Vargas-Zepeda J, Gomez-Alcala AV, Vasquez-Morales JA, Licea-Amaya L, De Jonckheere JF, Lores-Villa F. Successful treatment of Naegleria PAM using IV amphotericin B, fluconazole, and rifampin. Arch Med Res. 2005;36:83-6.
  5. Linam WM, Ahmed M, Cope JR, Chu C, Visvesvara GS, da Silva AJ, Qvarnstrom Y, Green J. Successful treatment of an adolescent with Naegleria fowleri primary amebic meningoencephalitis. Pediatrics. 2015;135:e744–8.
  6. Cope JR, Conrad DA, Cohen N, Cotilla M, DaSilva A, Jackson J, Visvesvara GS. Use of the novel therapeutic agent miltefosine for the treatment of primary amebic meningoencephalitis: report of 1 fatal and 1 surviving case. Clin Infect Dis 2016;62:774-6.
  7. John DT, John RA. Cytopathogenicity of Naegleria fowleri in mammalian cell cultures. Parasitol Res. 1989;76:20-5.