Background and objectives: The aim of this study was to evaluate the incidence and outcome of invasive fungal infections (IFI) in patients with hematologic malignancies.
Design and methods: This was a retrospective cohort study of patients admitted between 1999 and 2003 to 18 hematology wards in Italy. Each participating center provided information on all patients with newly diagnosed hematologic malignancies admitted during the survery period and on all episodes of IFI experienced by these patients.
Results: The cohort was formed of 11,802 patients with hematologic malignacies: acute leukemia (myeloid 3012, lymphoid 1173), chronic leukemia (myeloid 596, lymphoid 1104), lymphoma (Hodgkin's 844, non-Hodgkin's 3457), or multiple myeloma (1616). There were 538 proven or probable IFI (4.6%); 373 (69%) occurred in patients with acute myeloid leukemia. Over half (346/538) were caused by molds (2.9%), in most cases Aspergillus spp. (310/346). The 192 yeast infections (1.6%) included 175 cases of candidemia. Overall and IFI-attributable mortality rates were 2% (209/11802) and 39% (209/538), respectively. The highest IFI-attributable mortality rates were associated with zygomycosis (64%) followed by fusariosis (53%), aspergillosis (42%), and candidemia (33%).
Interpretation and conclusions: Patients with hematologic malignancies are currently at higher risk of IFI caused by molds than by yeasts, and the incidence of IFI is highest among patients with acute myeloid leukemia. Aspergillus spp are still the most common pathogens, followed by Candida spp. Other agents are rare. The attributable mortality rate for aspergillosis has dropped from 60-70% to approximately 40%. Candidemia-related mortality remains within the 30-40% range reported in literature although the incidence has decreased.