ABSTRACT
The frequency of invasive fungal disease due to systemic and opportunistic pathogens has increased dramatically over the past two decades (1-7). This increase in infections is associated with considerable morbidity and mortality (8-10) and is largely because of expanding patient populations at risk for the development of lifethreatening fungal infections, which include individuals undergoing solid-organ and blood and marrow transplantation (BMT), major surgery, those with AIDS, neoplastic disease, immunosuppressive therapy, and premature birth (2,4,6,10-13). Serious infections are being reported with an ever-increasing spectrum of pathogens including the well-known opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus (2,3,14,15). New and emerging pathogens include species of Candida and Aspergillus other than C. albicans and A. fumigatus, yeasts such as Trichosporon, Rhodotorula, andMalassezia species, hyaline hyphomycetes including Fusarium, Acremonium, and Paecilomyces species, and a wide variety of dematiaceous fungi (Table 1) (6,14-19). Modern medical mycology has become an extremely challenging study of infections caused by a broad range of taxonomically diverse opportunistic fungi (16). It is now quite clear that there are no nonpathogenic fungi; virtually any fungus can cause a lethal mycosis in an immunocompromised host.
