1. ACANTHAMOEBA There are four species belongs to Acanthamoeba species
Acanthamoeba culbertsoni – formely known
hartmanella culbertsoni
Acanthamoeba polyphaga
Acanthamoeba castellani
Acanthamoeba astromyxis

2. PROPERTIES OF ACANTHAMOEBA SPECIES
 They have trophozotes
They have polygonal double walled cysts
They differ from naegleria in not having flagellate stage and in forming cysts in tissues
SOURCES OF INFECTION OF ACANTHAMOEBA
Infection can be acquired by
Inhalation
Ingestion
Traumatized skin or eyes
From contaminated water

3. PATHOGENESIS OF ACANTHAMOEBA SPECIES
Following inhalation of acanthamoeba cyst the organism migrate into the upper and lower respiratory tract and then enter the blood circulation and reach the brain where continues to multiply and produce more cyst which cause granulomatous amoebic encephalitis.
For the case of chronic amoebic keratitis or keratouvetis of which over a thousands cases have been reported develops from the entry of amoebic cyst through abrasion on the cornea. The large majority of such cases have been associated with the use of contact lenses.

4. CLINICAL FEATURES GRANULOMATOUS AMOEBIC ENCEPHALITIS
Patient presenting with the following neurological signs and symptoms:
Seizures
Fever
Cranial nerve paralysis
Abnormal reflexes
Muscle weakness
Personality changes
Confusion
Comatose

5. CHRONIC AMOEBIC KERATITIS
Patient presents with the following features
Difficult in vision
Painful the eye
Tearing
Light sensitivity
Blindness

6. DIAGNOSIS OF ACANTHAMOEBA
Diagnosis of chronic keratitis is by demonstration of the cyst in cornea scraping by wet mount, histology and by culture. Growth can be obtained from the corneal scrapings inoculated on a nutrient agar, overlaid with live or dead Escherichia coli
Diagnosis of granulomatous amoebic encephalitis is by examination of cerebrospinal fluids (CSF). CSF shows lymphocytic pleocytosis. Acanthamoeba trophozotes and cysts can be demonstrated in brain biopsy by microscopy, culture and immunofloresence using monoclonal antibodies.

7. TREATMENT
Treatment with drugs such as propamidine, polyhexamethylene biguanide, chlorhexidine and ketoconazole along with surgical procedures has been found useful.

8. REFERENCE
Text book of medical parasitology, 6th Edition, by CK Jayaram Paniker