Cryptococcus gattii: An Emerging Cause of Fungal Disease in North America

During the latter half of the twentieth century, fungal pathogens such asCryptococcus neoformanswere increasingly recognized as a significant threat to the health of immune compromised populations throughout the world. Until recently, the closely related speciesC. gattiiwas considered to be a low-level endemic pathogen that was confined to tropical regions such as Australia. Since 1999,C. gattiihas emerged in the Pacific Northwest region of North America and has been responsible for a large disease epidemic among generally healthy individuals. The changing epidemiology ofC. gattiiinfection is likely to be a consequence of alterations in fungal ecology and biology and illustrates its potential to cause serious human disease. This review summarizes selected biological and clinical aspects ofC. gattiithat are particularly relevant to the recent North American outbreak and compares these to the Australian and South American experience.