Endogenous infections such as candidiasis can be minimized by oral fluconazole prophylaxis, although oral or intravenous amphotericin, or itraconazole, are suitable for certain patients. Exogenous fungal infections most commonly are transmitted by the airborne route, but the benefits of high-efficiency particulate air-filtered room air probably are diminishing as broad-spectrum prophylaxis against Aspergillus species and other fungi improves. However, high-risk environmental sources such as construction work always must be avoided near neutropenic patients. Reactivation of quiescent pulmonary Aspergillus infection can be prevented by surgical resection during remission, or by systemic amphotericin prophylaxis during subsequent neutropenic episodes.

Approximately 2 million nosocomial infections occur annually in the United States. These infections result in substantial morbidity, mortality, and cost. The excess duration of hospitalization secondary to nosocomial infections has been estimated to be 1 to 4 days for urinary tract infections, 7 to 8.2 days for surgical site infections, 7 to 21 days for bloodstream infections, and 6.8 to 30 days for pneumonia. The estimated mortalities associated with nosocomial bloodstream infections and pneumonia are 23.8% to 50% and 14.8% to 71% (overall), or 16.3% to 35% and 6.8% to 30% (attributable), respectively. The estimated average costs of these infections are $558 to $593 for each urinary tract infection, $2,734 for each surgical site infection, $3,061 to $40,000 for each bloodstream infection, and $4,947 for each pneumonia. Even minimally effective infection control programs are cost-effective. In countries with prospective payment systems based on diagnosis-related groups, hospitals lose from $583 to $4,886 for each nosocomial infection. As administrators focus on cost containment, increased support should be given to infection control programs so that preventable nosocomial infections and their associated expenditures can be averted.

Over the past decade, the incidence of hospital-acquired bloodstream infections caused by Candida strains has risen, while the implicated species have changed. Candida tropicalis, Candida parapsilosis, and Candida glabrata all have increased in incidence. Data from the Centers for Disease Control and Prevention reveal that, between 1980 and 1990, Candida emerged as the sixth most common nosocomial pathogen (7.2.%) and was the fourth most common pathogen in nosocomial bloodstream infections, surpassed only by coagulase-negative staphylococci, Staphylococcus aureus, and enterococci. The incidence of candidemia is dramatically higher in high-risk critical-care units: 25% of cases occur in surgical intensive-care units (ICUs) versus 25% in bone marrow transplantation units, 20% in medical ICUs, 20% in general medical wards, and 10% in oncology-hematology units. Burns and gastrointestinal surgery predispose to nosocomial candidemia. Independent risk factors include prior therapy with multiple antibiotics, isolation of Candida from sites other than blood, and prior hemodialysis. Crude mortality exceeds 55% and is associated with older age and concomitant renal failure, hepatic failure, acute respiratory diseases, or postoperative shock. In addition to extreme vigilance for early recognition of Candida sepsis in critically ill surgical patients, the high risk for candidemia probably necessitates fungal surveillance cultures and initiation of preemptive antifungal therapy in high-risk surgical patients.