Route of infection: across the olfactory epithelium in the nares
Time course: relatively acute (from 2 to 15 days)
Risk factors:
(1) swimming in a freshwater pond or lake
(2) organ transplant recipient
Clinical features:
(1) severe headache
(2) nausea and vomiting
(3) confusion and altered mental status progressing to coma
(4) lethargy
(5) rhinitis, stuffy nose or nasal discharge
(6) fever
(7) stiff neck
(8) purulent meningitis
(9) failure to respond to antibiotic therapy
Lesions in the CNS: hemorrhagic necrosis with purulence
Diagnosis - demonstration of trophozoites or cysts:
(1) brain biopsy
(2) examination of CSF
(3) culture (NNA seeded with E. coli, supplemented PYG, mammalian cell culture)
(4) indirect immunofluorescence
(5) PCR
