Reduction of invasive aspergillosis incidence among immunocompromised patients after control of environmental exposure.
BACKGROUND
The objective of the study was to assess the impact of the relocation of an adult hematological intensive care unit on invasive aspergillosis (IA) incidence.


METHODS
A quasi-experimental study, including a control group and an intervention group that both underwent pretest and posttest evaluations, was conducted in the 3 adult hematological intensive care units (each composed of 14 single rooms) in a university hospital from 14 April 2005 through 1 February 2006. One of these units was relocated from the main building to an adjoining modular construction. In this unit, 4 rooms were equipped with laminar airflow before relocation; all rooms were equipped with positive pressure isolation after relocation. The 2 other units (control group), each containing 8 rooms with laminar airflow, did not undergo environmental modification. The diagnostic criteria for IA were based on the criteria of the European Organization for Research and Treatment of Cancer.


RESULTS
In total, 356 hospitalized patients were included. Of the 21 cases of IA, 18 were nosocomial, and 3 were of undetermined origin. In the relocated unit, the incidence of IA decreased from 13.2% (9 patients) before relocation to 1.6% (1 patient) after relocation (P=.018). Eight of the 9 patients with IA before relocation stayed in rooms without specific air treatment. The rate of IA did not change in the control group. Patient characteristics were similar in each unit before and after relocation.


CONCLUSIONS
We detected a straightforward association between environmental modification and decreased IA incidence, which emphasizes the use of an environmental strategy, including high-efficiency air filtration, in the prevention of IA.
Bénet
Thomas
T
Department of Hygiene, Epidemiology, and Prevention, Hopital Edouard Herriot, Hospices Civils de Lyon, France.
Nicolle
Marie-Christine
MC
Thiebaut
Anne
A
Piens
Marie-Antoinette
MA
Nicolini
Franck-Emmanuel
FE
Thomas
Xavier
X
Picot
Stéphane
S
Michallet
Mauricette
M
Vanhems
Philippe
P
D000328:Adult; D001228:Aspergillosis / Q000453:epidemiology / Q000517:prevention & control*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D004781:Environmental Exposure / Q000517:prevention & control*; D005260:Female; D005602:France / Q000453:epidemiology; D006405:Hematology; D006749:Hospital Design and Construction / Q000379:methods; D006801:Humans; D016867:Immunocompromised Host; D015994:Incidence; D017053:Infection Control / Q000379:methods; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged