The relationship between Paracoccidioides brasiliensis and its environment is still a matter of debate as the fungus microniche is yet to be discovered. P. brasiliensis has deceived many of the researchers interested in finding its permanent residency. Many skin-testing surveys have been conducted with the aim of delimiting the areas of endemicity and of finding hyperendemic localities which could reveal P. brasiliensis habitat. The role of animals in determining the habitat of P. brasiliensis has not been so clear-cut; actually, only recently have they been proved to harbor the fungus in their tissues. The fungus has been isolated from soils only sporadically; in the past, only Negroni and Albornoz, succeeded in recovering P. Brasiliensis from soils; however, other workers failed in similar attempts. I. A. Conti-Diaz and F. D. Rilla have also proposed a theory to explain P. brasiliensis life cycle.