Airborne Aspergillus fumigatus levels outside and within a large clinical center
Related Experiment Video
Updated: Jul 8, 2026
Histological Quantification to Determine Lung Fungal Burden in Experimental Aspergillosis
Published on: March 9, 2018
Abstract:
Most considerations of Aspergillus fumigatus prevalence have implied that patterns of occurrence observed within London hospitals are generally applicable. Since prevalence data are almost nonexistent elsewhere, this assumption remains untested. To provide a comparison relevant to North America, we have monitored thermotolerant fungi outside as well as at two sites within the University Hospital, Ann Arbor, Michigan, during one year. Collections were made with paired Andersen samplers and malt agar for 30- to 40-min periods in a hallway adjacent to 6W, a general medical ward (47 days), and 2W, a lower level service and supply area (40 days); in addition, 10-min outdoor samples (44 days) were taken on an unobstructed hospital rooftop (out). Recoveries were analyzed after 3 and 7 days of 37 degrees C aerobic incubation. Virtually complete suppression of Cladosporium form species at 37 degrees left a mycoflora with A. fumigatus, A. niger, Paecilomyces spp., Mucor spp., and yeast/bacteria predominating. Although the proportions of samples yielding A. fumigatus were 76% for 6W, 57% for 2W, and 56% (out), levels exceeded 40 isolates/m3 only twice and were over 10 isolates/m3 on only 10 of 131 total samples. For 6W, 2W and out, respectively, means were 4.78, 1.97, and 6.25 isolates/m3; medians were 1.20, 1.05 and 1.75/m3 without annual trends indoors and with only a limited outdoor summer increase. Our data fail entirely to show the fall-winter abundance observed in the London report and suggest substantially lower indoor exposure levels of A. fumigatus than those noted in London.
Insights
This study monitored Aspergillus fumigatus in a US hospital, finding lower indoor levels and no distinct seasonal trends compared to London data. This highlights regional differences in airborne fungal exposure.
Area of Science:
- Environmental microbiology
- Hospital-acquired infections
- Fungal ecology
Background:
- Previous Aspergillus fumigatus prevalence studies focused on London hospitals.
- Assumed London-based prevalence patterns are globally applicable.
- Limited data exists for North American hospital fungal prevalence.
Purpose of the Study:
- To compare Aspergillus fumigatus prevalence in a North American hospital with London data.
- To monitor thermotolerant fungi, including A. fumigatus, indoors and outdoors.
- To assess potential differences in fungal exposure levels and seasonality.
Main Methods:
- One-year air sampling using Andersen samplers at two indoor hospital sites and one outdoor rooftop site in Ann Arbor, Michigan.
- Malt agar cultures incubated at 37°C for 3 and 7 days.
- Analysis of fungal isolates, focusing on Aspergillus fumigatus, Aspergillus niger, Paecilomyces, Mucor, and yeasts.
Main Results:
- Aspergillus fumigatus was detected in 76% (6W ward), 57% (2W service area), and 56% (outdoor) of samples.
- Fungal concentrations rarely exceeded 10 isolates/m³.
- Mean A. fumigatus concentrations were 4.78 (6W), 1.97 (2W), and 6.25 (outdoor) isolates/m³.
- Indoor A. fumigatus showed no annual trends; outdoor levels had a limited summer increase.
- Significantly lower indoor A. fumigatus levels were observed compared to London reports.
Conclusions:
- Hospital A. fumigatus prevalence in Ann Arbor, Michigan, differs from London findings.
- Indoor exposure levels in this North American hospital are substantially lower than reported in London.
- Observed patterns do not support the assumption of universal applicability of London-based A. fumigatus prevalence data.
More Related Videos
15:01Confocal Laser Scanning Microscopy-Based Quantitative Analysis of Aspergillus fumigatus Conidia Distribution in Whole-Mount Optically Cleared Mouse Lung
Published on: September 18, 2021
10:33Isolation of Culturable Yeasts and Molds from Soils to Investigate Fungal Population Structure
Published on: May 27, 2022
Related Concept Videos
01:25Transmission-based Precautions II: Airborne and Protective Environment
Airborne precautions:
Use airborne precautions when treating patients known or suspected to have diseases that spread through the air—for example, tuberculosis or measles. These organisms are present in smaller droplets expelled by an infected person and...
01:20Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...
01:28Fungal Phylum Ascomycota