Objective: Filamentous fungi constitute an increasingly important cause of morbidity and mortality in immunocompromised patients, who acquire them mainly through their respiratory system. The objective of this study was to determine the environmental fungal load (FL) in the air of high-risk hospital departments (depts), the drug susceptibility of the isolated fungi and the correlation of FL with nosocomial invasive fungal infections (IFI). Materials and methods: The study took place in a 1030- bed Greek tertiary hospital. From l-12/2000 and once per month, in Haematology (H), Paediatric Oncology (P) and Solid Organ Transplantation (T) departments, 1.6 m3 of air were sampled. All samples were incubated at 37"C, colonies grown were then inoculated onto SDA plates and the isolated fungi were finally identified. Twelve A. fumigatus, 12 A. flavus and 12 A. niger isolates were randomly chosen and tested for MICs (no visual growth) of amphotericin B (AmB), itraconazole (ITC), voriconazole (VRC) and posaconazole (PSC) by NCCLS M38-P micro-method. During the sampling period, a surveillance of IF1 was also taking place. Results: ’Ibe median of monthly FL measurements was 8.7 cfu/m3 (range 1.2-28.3) in P, 16.5 (range 0.6-54.9) in T and 23.1 (range 15-44.9) in H. In all departments, FL was higher in summer and early autumn when the humidity and temperature were higher. FL was considerably higher in H where the building was old and renovation works were in progress in direct proximity with the ward, whereas it was much lower in P, situated in a new building. Aspergillus spp. dominated (64.9%) with niger,jlavus andfimigatus being the most prevalent isolates. Other Aspergillus spp. included nidulans and terreus; whereas, other filamentous fungi isolated were mainly zygomycetes (most commonly Rhizopus spp.) as well as dematiaceous fungi (Alternaria, Dreschlera and Curvularia spp.).The MIC90s for all the strains were 0.5 mgll for PSC, 1 mg/l for AmB and VRC and 4 mg/l for ITC. Although there were variations in FL observed, no cases of probable or definite IF1 (EORTUMSG criteria) were recorded during the period of air surveillance in the 3 depts. Conclusions: A considerable number of filamentous fungi are found in the hospital environment mainly consisting of A. niger, A. flavus and A. fumigatus. Elevations of FL coincided with renovation activity as well as with humid and warm weather. While none of the three Aspergillus spp. possess unusual patterns of antifungal drug resistance, they are generally more susceptible to the newer azoles than to ITC. In our study, the height of FL does not correlate with the incidence of IFI.
Full conference title:
12th International Symposium on Infections in the Immunocompromised Host
- ISIIH 12th