Airborne fungal spore monitoring in a protective environment during hospital construction, and correlation with an outbreak of invasive aspergillosis.

OBJECTIVE: Evaluate aerobiological monitoring for fungal spores during hospital construction and correlate results with an outbreak of invasive aspergillosis (IA).
DESIGN: Prospective air sampling for molds was done using the gravity air-settling plate (GASP) method.
SETTING: A university medical center special care unit consisting of single-patient rooms with high-efficiency particulate air filtration under positive pressure. PATIENTS: Five neutropenic patients who subsequently developed IA.
RESULTS: Four of the five patients with IA were housed in rooms adjacent to a construction staging area. Aerobiological monitoring detected an increase in the number of airborne fungal spores including Aspergillus species in these rooms; however, increased counts preceded IA diagnosis by 1 to 7 days in only three of the five patients. Swab cultures of the exhaust vents within each room confirmed results from air-settling plates. Follow-up monitoring, using the GASP method, demonstrated that control procedures were effective in reducing air mold contamination.
CONCLUSION: The GASP method, although able to demonstrate that infection control measures reduced mold contamination of the air, was insensitive to detect levels of mold contaminates in time to prevent IA.