Hospital environment and invasive aspergillosis in patients with hematologic malignancy

Background: To determine whether there is a correlation between sources of Aspergillus spores in a high-efficiency particulate air (HEPA)-filtered environment and nosocomial invasive aspergillosis (IA), we performed a detailed environmental assessment and case review. Methods: From April to October 2004, 626 bioaerosol samples, 1,257 surface samples, and 607 water samples were obtained from 74 HEPA-filtered air hospital rooms occupied by 458 patients with hematologic malignancies. Samples were collected prospectively from the room before and after cleaning within 1 hour of patient admission or discharge. Aspergillus spp was isolated from 21 surface samples and 46 bioaerosol samples. Interestingly, Aspergillus spp was not isolated from any water samples. Results: Aspergillus spp was isolated from 21 surface samples and 46 bioaerosol samples. Interestingly, Aspergillus spp were not isolated from any water samples. The majority (90%) of the positive bioaerosol samples had <= 10 colony-forming units of Aspergillus/m3 of air. Only 2 patients developed nosocomial IA. No correlations were found between Aspergillus species isolated from the hospital rooms and those causing IA. Conclusion: The risk of hematologic malignancy patients acquiring nosocomial aspergillosis from water or HEPA-filtered air is very low. Copyright (C) 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.