Clinical Information

Cryptococcosis is an invasive fungal infection caused by Cryptococcus neoformans or Cryptococcus gattii. C neoformans has been isolated from several environmental sources, especially weathered pigeon droppings. Historically, C gattii was associated with tropical and subtropical regions. More recently, it has been recognized as endemic in British Columbia and the Pacific Northwestern US and is associated with several different tree species.

Infection is usually acquired via the pulmonary route. Patients are often unaware of any exposure history. Approximately half of the patients with symptomatic disease have a predisposing immunosuppressive condition such as AIDS, steroid therapy, lymphoma, or sarcoidosis. Symptoms may include fever, headache, dizziness, ataxia, somnolence, and cough. While the majority of C neoformans infections occur in immunocompromised patient populations, C gattii has a greater predilection for infection of healthy individuals.(1,2)

In addition to the lungs, cryptococcal infections often involve the central nervous system (CNS), especially in patients with HIV infection. Mortality among patients with CNS cryptococcosis may approach 25% despite antifungal therapy. Untreated CNS cryptococcosis is invariably fatal. Disseminated disease may involve any organ system and usually occurs in immunosuppressed individuals.