Meningoencephalitis due to Acanthamoeba SP. Pathogenesis and clinico-pathological study

Area of Science:

• Neurology
• Infectious Diseases
• Parasitology

Background:

• Amebic Meningoencephalitis (AM) and Primary Amebic Meningoencephalitis (PAM) are severe central nervous system infections.
• AM is caused by Acanthamoeba (A. sp.), often in immunocompromised individuals.
• PAM is caused by Naegleria fowleri, typically affecting healthy individuals after swimming.

Purpose of the Study:

• To differentiate the clinical presentations and pathological characteristics of AM and PAM.
• To elucidate the distinct host-pathogen interactions and routes of infection for each disease.

Main Methods:

• Comparative analysis of clinical case reports and neuropathological findings.
• Histopathological examination of central nervous system tissues.
• Discussion of diagnostic techniques including immunofluorescent antibody techniques (IFAT) and electron microscopy.

Main Results:

• AM presents as subacute/chronic granulomatous meningoencephalitis with cysts and trophozoites, often with hematogenous spread.
• PAM is an acute hemorrhagic necrotizing meningoencephalitis with only trophozoites, entering via the olfactory epithelium.
• Host response in AM involves lymphocytes, plasma cells, and giant cells; PAM shows acute inflammation.

Conclusions:

• AM and PAM exhibit distinct epidemiological, clinical, and pathological features.
• Understanding these differences is crucial for accurate diagnosis and management of amebic CNS infections.
• Advanced techniques like IFAT and electron microscopy aid in identifying causative agents.