Naegleriasis

Naegleria fowleri, a free-living amoeba is found in lakes, especially warm ones, and in swimming pools ( Amoebae). It infects healthy young people. In a small percentage of those exposed, it invades the nasopharynx and reaches the brain where it gives rise to acute meningoencephalitis with trophozoites but without cysts. Because of the fast multiplication of the amoebae, clinical infection usually leads to death in a few days. Large numbers of amoebae are present in the subarachnoid space, penetrating into the underlying cortex, but there is little (neutrophilic or monocytic) or no inflammatory reaction ( Pathology/Fig. 4). Mobile amoebae are often found in the cerebrospinal fluid. Uncal herniation is the usual cause of death. A thick “exudate,” mostly amoebae, covers the brain and spinal cord and is most apparent over the sulci, major fissures, and basal cisterns.

Main clinical symptoms: Meningoencephalitis (= primary amoebic meningoencephalitis = PAME), often leading to death within...