TABLE 1.

Characteristics of BAE

Characteristic and comments
Susceptible hosts
    Immunocompromised hosts, including HIV/AIDS patients or individuals undergoing organ transplantation or steroid treatment, as well as drug and alcohol abusers; immunocompetent hosts usually include young children and older individuals
Symptoms
    Headache, fever, nausea, mental state abnormalities, irritability, hemiparesis, cranial nerve palsies, hallucinations, photophobia, sleep and speech disturbance, and seizures
Risk factors
    Breaks in the skin, working with soil without protective clothing
Incubation period
    Weeks to months
CSF parameters
    High protein levels, low glucose levels, amoebae rarely found in the CSF
Gross pathology
    Multiple necrotic lesions in the brain
Histopathology
    Cysts and trophozoites found in the perivascular spaces, inflammation with or without granulomas
Laboratory diagnosis
    Wet mounts of CSF may show the presence of amoebae; indirect immunofluorescence assay of tissue sections, using anti-Balamuthia sera, is recommended; in addition, inoculating a portion of clinical sample on a mammalian cell monolayer may result in the isolation of B. mandrillaris
Prognosis
    Extremely poor, with a >98% fatality rate