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Microbiology and Epidemiology
Cryptococcus is a yeast-like fungus. C. neoformans and C. gattii are pathogenic for humans and can cause cryptococcosis; most clinical laboratories do not routinely distinguish between these species.
- Worldwide, there are ~1 million cases of cryptococcosis, with >600,000 deaths annually. Most cases are in pts with AIDS.
- Cryptococcosis due to C. neoformans is rare in the absence of impaired immunity; in contrast, C. gattiirelated disease often occurs in immunocompetent pts.
- C. neoformans is found in soil contaminated with pigeon droppings, whereas C. gattii is associated with eucalyptus trees. Most cases are acquired via inhalation, which results in pulmonary infection.