Invasive fungal infections are increasing causes of morbidity and mortality in hospitalized patients for several reasons: (1) The widespread use of potent broad-spectrum antibiotics allows fungal overgrowth; (2) The increasing application of critical care services has given rise to larger numbers of patients with indwelling catheters and various host defences that are compromised in multiple ways; (3) Chemotherapy regimens have intensified, and new immunomodulatory therapies have been introduced for the management of neoplastic diseases; (4) Organ transplantation occurs for ever-increasing indications in modern medical practice. As a consequence, not only is the pool of susceptible patients growing, but with more effective antibacterial treatments, superinfections by fungi are more likely.
During the 1980s, the rate of fungal infections in hospitalized US patients doubled, with increases occurring in both medical and surgical patient populations. During the 1990s, this trend did not abate. At the same time, mortality from [Candida] infection in hospitalized patients declined, because of improvements in both early detection (through heightened awareness and improvements in culture techniques) and management of invasive [Candida] infections. In contrast, there was a relentless rise in mortality from [Aspergillus] infection, which has now surpassed the mortality rate from [Candida] infection.