🦠microbiology review

Primary amoebic meningoencephalitis (PAM)

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Primary amoebic meningoencephalitis (PAM) is a rare but often fatal brain infection caused by the free-living amoeba Naegleria fowleri. It typically occurs when contaminated water enters the nose and reaches the brain.

5 Must Know Facts For Your Next Test

  1. Naegleria fowleri is commonly found in warm freshwater environments, such as lakes and hot springs.
  2. Initial symptoms of PAM include headache, fever, nausea, vomiting, and stiff neck.
  3. The disease progresses rapidly, often resulting in death within about five days of symptom onset.
  4. Diagnosis is typically made through cerebrospinal fluid (CSF) analysis using microscopy, culture, or PCR techniques.
  5. Treatment options are limited but may include amphotericin B and other antifungal medications.

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