C. neoformans may be cultured without too much difficulty on chocolate agar or standard fungal media, such as Mycosel or Sabouraud's medium. The organism usually grows within 4 to 7 days after inoculation. It is presumed that infection with C. neoformans is acquired by inhaling particles laden with the organism. Exposure to pigeon excreta appears to be the major cause of disease.
Asymptomatic infection is probably quite widespread.
Cryptococcosis occurs more commonly in men, possibly because of occupational or vocational exposure to the organism. Race and age offer no special predisposition, although most patients are adults. The majority of patients who acquire clinical cryptococcosis have significant recognizable host defense defects. However, invasive cryptococcal infection can occur in apparently healthy persons, presumably from intensive exposure. Aerosolized organisms are inhaled and delivered to the far periphery of the lung, where subpleural infection is established.