Outbreak of InvasiveAspergillusInfection in Surgical Patients, Associated with a Contaminated Air‐Handling System

Abstract

An outbreak of Aspergillus infection at a tertiary care hospital was identified among inpatients who had amputation wounds, peritonitis, allograft nephritis, or mediastinitis. During a 2-year period, 6 patients were identified, all of whom had Aspergillus species recovered from samples from normally sterile sites. All cases clustered in the operating theater during a single 12-day period. To assess operating theater air quality, particle counts were measured as surrogate markers for Aspergillus conidia. A substantial increase in the proportion of airborne particles > or =3 microm in size (range, 3-fold to 1000-fold) was observed in many operating rooms. A confined space video camera identified moisture and contamination of insulating material in ductwork and variable airflow volume units downstream of final filters. No additional invasive Aspergillus wound infections were identified after the operating theater air-handling systems were remediated, suggesting that this unusual outbreak was due to the deterioration of insulating material in variable airflow volume units.

Fungal Air Quality in Medical Protected Environments

“…By keeping lower fungal concentrations in areas around units with risk patients, it is also possible to find better air quality in clinical units. Some outbreaks have been described following failures in air-filtration systems or by the presence of contaminated air-handling systems (Lutz et al, 2003;Muñoz et al, 2004). A. fumigatus was responsible for the fungal infections, in most cases.…”

The architecture of safety: hospital design

“…Airborne infections are spread when dust and pathogens are released during hospital construction [3][4][5][6] and due to contamination and malfunction of hospital ventilation systems [7][8][9][10]. Studies in hospitals show that fungal load in the air may be linked to humidity, temperature and construction activity [e.g., 6*].…”

Mediastinitis in pediatric cardiac surgery: Prevention, diagnosis and treatment

“…In the sucker system tubing, room air is mixed with blood and thus potentially contaminated air enters into the bypass circuit. There is some evidence of transmission of fungal infections through contaminated air-handling systems [43,44] , and air filtration as well as radiation were considered efficient ways to protect from mediastinitis [45][46][47] . Gram negative bacilli may also be transmitted from the environmental flora [48] but contamination with coagulase negative staphylococci is probably only due to patient or surgical team flora [49] .…”