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.