Cryptococcosis

Definition:

A rare fungal infection caused by inhaling the fungus, Cryptococcus neoformans.

Causes, incidence, and risk factors:

This fungus is found in soil and in pigeon droppings. Once in the lung, infection with cryptococcosis may heal on its own, remain localized, or spread throughout the body (disseminate). Most cases occur in people whose resistance to infection is lowered (through HIV infection, high doses of corticosteroid medications, cancer chemotherapy, Hodgkin's disease). In individuals with a normal immune system the pulmonary (lung) form may have no symptoms. The cryptococcus organism has an affinity for the brain. Once infected the onset of neurological symptoms is gradual. The majority of people have meningoencephalitis at the time of diagnosis.

Of the opportunistic fungal infections, cryptococcus is the most frequently seen life-threatening infection in AIDS patients.