# Cryptococcus: History, Epidemiology and Immune Evasion
## 4 _Cryptococcus gattii_  
The first clinical sample finding of _C. gattii_ came from the cerebrospinal fluid of a Congolese individual, initially reported as _C. neoformans_ in 1894. Only in later years, the yeast with an atypical elliptical shape would be confirmed as _C. gattii_[2]. Initially, _C. gattii_ was not classified as a species on it own, but considered a _Cryptococcus neoformans_ variant [24]. Differentiation between the yeasts was made using CBD medium, still used to differentiate the species and consisting of an agar solution containing canavanine-glycine-bromothymol blue. _C. neoformans_ only uses glycine as a carbon source and does not show favorable growth in the presence of canavanine [25]; however, _C. gattii_ grows well on this medium and uses glycine not only as a carbon source, but also as a source of nitrogen, thus, alkalinizing the medium, granting it a bluish tinge due to the pH indicator bromothymol blue [26]. Unlike _C. neoformans_, which is ubiquitously distributed in soil and plant species, _C. gattii_ is found specifically in plant material, mainly in urban landscape trees and in tree species associated with tropical and subtropical climates, such as in forests of _Eucalyptus_ spp. in Australia [27]. The most common variants of _C. gattii_ are the globally distributed VGI and VGII, both responsible for causing most cases of _C. gattii_ cryptococcosis in immunocompetent individuals [28; 29]. The variants of _C. gattii_ are more frequent in warmer morphclimatic domains, such as the predominant VGII in the Brazilian territory, with findings in the Amazon biome [30; 31; 32], clinical isolates from the Brazilian Northeast [33], Central-West [34] and the Brazilian Southeast [35; 36; 37], as well as in northern Australia and the islands of Papua New Guinea [8]. However, there is a trend of VGII findings causing outbreaks of _C. gattii_ in temperate regions around the world, as has been observed with large numbers of domestic animals infected with _C. gattii_ reported in western Australia [38], in outbreaks of _C. gattii_ in North America from Vancouver Island in Canada, which resulted in cases of infections both in wildlife and domestic animals [39; 40], along with an outbreak of cases in immunocompetent and immunocompromised humans in 1999 [41]. This outbreak also contributed to the expansion of new cases in the Northwest Pacific Coast of the United States of America, in Washington and Oregon, and more recently in the Southeast of the USA [42; 43]. These cases obtained their clinical findings with evidence of a genetic profile from the tropical forests of South America [44; 45]. However, more recent analyses indicate a high genetic diversity of the population in the Brazilian variant _C. gattii_ VGII changing the origin of this variant from the Amazon rainforest to the Brazilian semi-arid northeast [46]. Thus, the data suggest a change in the dynamics of the global dissemination of _C. gattii_, associating it to the current scenario of climate change and global warming that favors the increase in new cases of _C. gattii_ infections by facilitating its spread [47].