Opportunistic infection: Cryptococcal meningitis

Cryptococcus neoformans is a fungus of which the spores are present in the environment and can be inhaled.

The fungus initially grows in the lungs but often spreads to the membranes surrounding the brain (meninges) and is a common cause of meningitis (inflammation of the meninges) in people with late stage AIDS.

Symptoms and diagnosis
The usual symptoms of cryptococcal meningitis are headache and altered mental state, with or without a fever. Sometimes there are seizures or signs of nerve damage in a particular region of the brain. In people with AIDS there are a number of other infections of the brain and meninges that can cause similar symptoms.

If there are no signs of raised pressure in the brain, a lumbar puncture will be done to obtain a sample of the fluid around the brain (cerebrospinal fluid) in order to make a diagnosis. If cryptococcus is present it may be immediately visible under the microscope in the cerebrospinal fluid or be detectable by a rapid test for cryptococcal protein, otherwise culture of the fluid may be necessary.

Treatment
The initial treatment for cryptococcal meningitis requires admission to hospital, since a drug called amphotericin B must be given intravenously for seven to 14 days. This is followed by another eight to 10 weeks of treatment with a drug called fluconazole, which can be taken by mouth.

Without highly active antiretroviral treatment, cryptococcal disease will recur, and lifelong treatment with fluconazole is necessary.