- Acanthamoeba and Naegleria fowleri are free-living amoeba which exist in water and moist environments.
- Acanthamoeba encephalitis only occurs in those with previous chronic illness and in immunocompromised patients, such as AIDS patients. Unlike Naegleria infections of the CNS which manifest acutely, the course of acanthamoeba infections is typically indolent and progresses over weeks. Disease manifests with insidious onset of focal neurological impairments and headache. Wet mount examination of CSF will reveal amoeba. Infection is almost always fatal.
- Infection of the cornea by acathamoeba can occur in healthy individuals. Infection is usually preceded by overt corneal trauma or due to long-term or improper use of contact lenses which may induce micro-abrasions on the corneal surface. Without rapid treatment, infection can cause blindness.