Primary amebic meningoencephalitis (PAM) is a condition brought on by an infection with Naegleria fowleri, a microscopic amoeba referred to as a “brain-eating amoeba.” Because this infection damages brain tissue, it frequently results in fatal brain swelling and death. PAM is uncommon and mainly affects otherwise healthy adolescents, teenagers, and young adults.

By ingesting water contaminated with the amoeba through the nose, people can get infected with Naegleria fowleri. Infection may be more prevalent when water enters the nose under pressure, such as while diving into water. Swallowing polluted water does not cause infection. Naegleria fowleri cannot be transmitted from person to person.

After swimming or having subsequent nasal exposure to water containing Naegleria, symptoms begin 1 to 12 days (median 5 days) later. People die between 1 and 18 days (median 5 days) following the onset of symptoms. PAM is a difficult disease to diagnose since it advances quickly, and sometimes a diagnosis is made after the patient has passed away.

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

Primary amebic meningoencephalitis (PAM) is treated with a cocktail of medications that may include amphotericin B, azithromycin, fluconazole, rifampin, miltefosine, and dexamethasone. Because they have been used to treat patients who have survived, these medications are believed to be effective against Naegleria fowleri. Miltefosine, the most recent of these medications, has been demonstrated in the laboratory to kill free-living amebae, including Naegleria fowleri.