Indirect immunofluorescent identification of Acanthamoeba causing meningoencephalitis

Area of Science:

• Medical Mycology
• Infectious Diseases
• Neuroparasitology

Background:

• Primary amoebic meningoencephalitis (PAM) is a rare but severe brain infection.
• Naegleria fowleri is the most common etiological agent of PAM in humans.
• Acanthamoeba species are also known to cause PAM, though less frequently.

Observation:

• Three recent human cases of PAM were identified.
• Unlike typical Naegleria-induced PAM, these cases exhibited a more chronic clinical course.
• Patient survival ranged from 2 to 6 weeks post-onset.

Findings:

• The causative agent in two cases was identified as Acanthamoeba castellanii.
• The third case was attributed to Acanthamoeba culbertsoni.
• Etiological identification was performed post-mortem.

Implications:

• Highlights the potential for Acanthamoeba to cause chronic PAM, challenging the perception of PAM as exclusively an acute illness.
• Underscores the importance of considering Acanthamoeba in the differential diagnosis of meningoencephalitis, particularly in chronic or atypical presentations.
• Emphasizes the need for improved diagnostic methods for amoebic encephalitis, especially for post-mortem identification.