- Email: [email protected]
Mobile air-decontamination unit and filamentous fungal load in the hematology ward: How efficient at the low-activity mode?
Mobile air-decontamination unit and filamentous fungal load in the hematology ward: How efficient at the low-activity mode? Marie-Pierre Brenier-Pinchart, MD, PhD,a Laurence Coussa-Rivie`re,a Bernadette Lebeau, MD,a Marie-Reine Mallaret, MD,b Claude-Eric Bulabois, MD,c Se´bastien Ducki, MD,b Jean-Yves Cahn, MD,c Rene´e Grillot, PharmD, PhD,a and Herve´ Pelloux, MD, PhDa Grenoble, France
Air treatment with a mobile Plasmair air-decontamination unit significantly reduces the fungal spore load in hematology wards. We report that this system used at a low aspiration flow does not perform total biodecontamination against filamentous fungi. Moreover, the filamentous fungus load remaining in rooms equipped with this mobile air-decontamination unit is lowest in wards in which other preventive measures against nosocomial filamentous fungal infections are implemented. Copyright ª 2009 by the Association for Professionals in Infection Control and Epidemiology, Inc. (Am J Infect Control 2009;37:680-2.)
A significant relationship between the degree of fungal air and surface contamination in hematology wards and the incidence of invasive nosocomial aspergillosis (INA) has been demonstrated in nonepidemic situations.1,2 The reduction in or elimination of airborne fungal contamination in the environment is a main objective of the wards in which patients at risk for INA are hospitalized.2 Recently, 2 different mobile air-decontamination units were evaluated for their protection of immunosuppressed patients against airborne contamination: Plasmair3,4 and Immunair5 (AirInSpace, Sterling, VA). These 2 units use the same novel technology to destroy airborne microorganisms. Sixt et al3 and Sautour et al4 showed that the mobile Plasmair unit reduces indoor fungal contamination and may help reduce spore load during renovation work. The unit has 3 modes
From Parasitology and Mycology Laboratory,a Hospital Hygiene Unit,b and Hematology,c Grenoble Universitary Hospital and Joseph Fourier University, Grenoble, France. Address correspondence to Marie-Pierre Brenier-Pinchart, MD, PhD, Parasitologie-Mycologie, Poˆle de Biologie, Centre Hospitalier Universitaire, BP 217, 38043 Grenoble Cedex 9, France. E-mail: MPBrenierPinchart@ chu-grenoble.fr.
0196-6553/$36.00 Copyright ª 2009 by the Association for Professionals in Infection Control and Epidemiology, Inc. doi:10.1016/j.ajic.2008.12.006
680
of activity, corresponding to different situations: ‘‘activity mode’’ (1000 m3/hour; 59 dB), ‘‘day mode’’ (650 m3/ hour; 51 dB), and ‘‘night mode’’ (450 m3/hour; 44 dB). The effectiveness of this mobile air-treatment system used at a high aspiration flow rate was demonstrated in one hematology ward of our hospital,6 but some adult patients complained of excessive noise when staying for long periods in a room in which this device was in use. The objective of our study was to prospectively evaluate the reduction in fungal contamination from the use of the Plasmair mobile air-decontamination unit at a low aspiration flow rate (450 m3/hour) during the day in the absence of care, with this function being less noisy for the patients. Between July 24, 2006 and September 1, 2006, the air and surface fungal contamination of 18 rooms equipped with Plasmair and 18 rooms without specific air treatment (conventional rooms) were studied in 2 adult hematology wards, designated WA and WB. In these wards, partial air control was provided by airconditioning with 85% central opacimetric filtration. Hematology ward WA included 7 beds (in 6 patient rooms); the nursing staff had attended specialized training, and the main unit entrance had a door that closed automatically. Hematology ward WB had 21 beds (in 13 patient rooms) with a main entrance door that did not close automatically and was closed less systematically. WA had 1 Plasmair unit, and WB had 2 Plasmair units. The patients with
Brenier-Pinchart et al.
www.ajicjournal.org Vol. 37 No. 8
681
measured in rooms with the Plasmair unit operated at a low aspiration flow rate was counted. We found that the mobile Plasmair unit used at a low aspiration flow rate (night mode) significantly reduced indoor fungal contamination of air and surfaces in the 2 hematology wards. Under our study conditions, the fungal loads measured in rooms equipped with a Plasmair unit were lower than those reported by Sixt et al,3 but higher than those measured previously in the air of these wards with the Plasmair unit operated at a high aspiration flow rate (ie, 0.85 CFU/m3).6 Furthermore, Sixt et al3 did not distinguish among the Plasmair unit’s 3 modes of activity. But although no agreement exists as to the spore concentration threshold at which a significant risk of invasive fungal infections occurs,8 the FF level obtained in our conditions cannot be considered sufficiently low to allow any risk of FF contamination to be ruled out. We also cannot disregard the importance of other preventive measures that should be associated with the use of the Plasmair unit. WA and WB used different behavioral practices aimed at invasive filamentous fungal infections prevention. The FF load in the corridors was much higher in WB than in WA, in which the preventive measures were more drastic. This difference also was found in conventional rooms, with a more significant reduction in overall fungal contamination in WA than in WB. Since the end of our study, a new Plasmair device has become available with higher aspiration flow rates (500 to 2000 m3/h) and a clear improvement in noise level (1000 m3/h; 47 dB). This new model is as silent at a high aspiration flow rate as the model that we used in the night mode. In conclusion, the Plasmair mobile air-decontamination unit may be helpful in reducing fungal spore load, but its preferred mode of operation is at a high aspiration flow rate. The use of other preventive measures is necessary to limit the entry of spores in rooms equipped with this unit. The Plasmair unit also may be proposed in other wards besides hematology
agranulocytosis were hospitalized in rooms in which the Plasmair unit was associated with preventive measures. Nine surface samples per room were obtained using contact plates (Merck KGaA, Darmstadt, Germany), and 1 m3 of air per room was collected with an Air Ideal 90-mm biocollector (bioMe´rieux, Marcy L’Etoile, France) (2 3 500 L, placed 1 m away from the bed) loaded with Sabouraud chloramphenicol plates (AES Chemunex, BRUZ Cedex, France). In addition, 1 m3 of air was collected in the corridor of each unit. All samples were incubated at 278C for 7 days. Filamentous fungi (FF) were counted as colony-forming units (CFU) per plate or per m3 of air and identified based on their macroscopic and microscopic characteristics.7 Species identification was performed for Aspergillus fumigatus. The number of CFU per m3 or per room was evaluated for significance by Student’s t-test using Statview software (SAS Institute, Cary, NC). During this 6-week prospective study, 324 surface samples and 72 air samples (36 m3) were studied in 36 rooms. FF was found in 49 surface samples (mean level, 2.4 6 3.2 CFU/room) and in 62 air samples (mean, 9.8 6 12.4 CFU/m3). A mean FF level of 17.5 6 12.9 CFU/m3 was found in the corridors. Overall, the level of FF contamination was significantly higher in WB than in WA (3.3 6 3.6 CFU/room in WB vs 0.6 6 1.1 CFU/room in WA for surface samples; 12.9 6 14.1 CFU/m3 in WB vs 3.8 6 3.7 CFU/m3 in WA for air). A fumigatus was isolated on only 3 occasions in the air of the conventional rooms (1 room in WA and 2 rooms in WB) and never in any of the Plasmair-treated rooms. In both WA and WB, a significant reduction was observed in the overall fungal contamination of surfaces and air in rooms in which the Plasmair unit was used at a low aspiration flow rate compared with conventional rooms (Table 1). The Plasmair-equipped rooms displayed decreases in FF load of 86% in surface samples and 80% in air samples compared with nonequipped rooms. However, the decontamination was not total, since a mean FF load of 3.2 6 2.8 CFU/m3 of air
Table 1. Mean (6 SD) fungal load of air and surface collected in rooms treated or not treated with Plasmair at low flow (450 m3/h) in 2 hematology wards Rooms
Corridors 3
Surface, CFU/room
WA (12 rooms) WB (24 rooms) Total
Air, CFU/m3
Air, CFU/m
Plasmair treatment (n 5 162)*
No air treatment (n 5 162)
Plasmair treatment (n 5 18 m3)
No air treatment (n 5 18 m3)
(n 5 18 m3)
0y 0.8 6 0.7y 0.6 6 0.7y
1.2 6 1.3 5.8 6 3.5 4.3 6 3.7
1.5 6 0.5y 4 6 3.2y 3.2 6 2.8y
6.2 6 4.1 21.7 6 15.4 16.5 6 14.7
5.8 6 5.4 23.1 6 12 17.5 6 12.9
*Number of contact samples. y P , .05 (Plasmair treatment vs no treatment).
682
Brenier-Pinchart et al.
wards, because of the presence of INA in patients hospitalized in these wards as well.9 We thank S. Durville for rereading the manuscript and also thank the nursing staff of the 2 hematology wards.
References 1. Alberti C, Bouakline A, Ribaud P, Lacroix C, Rousselot P, Leblanc T, et al. Relashionship between environmental fungal contamination and the incidence of invasive aspergillosis in haematology patients. J Hosp Infect 2001;48:198-206. 2. Tablan OC, Anderson LJ, Besser R, Bridges C, Hajjeh R. Centers for Disease Control and Prevention, Healthcare Infection Control Practices Advisory Committee. Guidelines for preventing health-care-associated pneumonia, 2003: recommendations of the CDC and the Healthcare Infection Control Practices Advisory Committee. MMWR Morb Mortal Wkly Rep 2004;53:1-36. 3. Sixt N, Dalle F, Lafon I, Aho S, Couillault G, Valot S, et al. Reduced fungal contamination of the indoor environment with the Plasmair system (AirInSpace). J Hosp Infect 2007;65:156-62.
American Journal of Infection Control October 2009 4. Sautour M, Sixt N, Dalle F, L’Ollivier C, Calinon C, Fourquenet V, et al. Prospective survey of indoor fungal contamination in hospital during a period of building construction. J Hosp Infect 2007;67: 367-73. 5. Poirot JL, Gangneux JP, Fisher A, Malbernard M, Challier S, Laudinet N, et al. Evaluation of a new mobile system for protecting immune-suppressed patients against airborne contamination. Am J Infect Control 2007;35:460-6. 6. Reboux G, Poirot JL, Mallaret MR, Labrousse H, Descamps F, Sixt N, et al. Prevention of airborne fungal infection and cross-contaminations using the Plasmair unit. In Proceedings of the Congress of the International Society for Human and Animal Mycology, 2006; abstract P-0303. 7. Faure O, Fricker-Hidalgo H, Lebeau B, Mallaret MR, Ambroise-Thomas P, Grillot R. Eight-year surveillance of environmental fungal contamination in hospital operating rooms and hematological wards. J Hosp Infect 2002;50:155-60. 8. Munoz P, Burillo A, Bouza E. Environmental surveillance and other control measures in the prevention of nosocomial fungal infections. Clin Microbiol Infect 2001;7:28-45. 9. Fourneret-Vivier A, Lebeau B, Mallaret MR, Brenier-Pinchart MP, Brion JP, Pinel C, et al. Hospital-wide prospective mandatory surveillance of invasive aspergillosis in a French teaching hospital (2000-2002). J Hosp Infect 2006;62:22-8.
Air treatment with a mobile Plasmair air-decontamination unit significantly reduces the fungal spore load in hematology wards. We report that this system used at a low aspiration flow does not perform total biodecontamination against filamentous fungi. Moreover, the filamentous fungus load remaining in rooms equipped with this mobile air-decontamination unit is lowest in wards in which other preventive measures against nosocomial filamentous fungal infections are implemented. Copyright ª 2009 by the Association for Professionals in Infection Control and Epidemiology, Inc. (Am J Infect Control 2009;37:680-2.)
A significant relationship between the degree of fungal air and surface contamination in hematology wards and the incidence of invasive nosocomial aspergillosis (INA) has been demonstrated in nonepidemic situations.1,2 The reduction in or elimination of airborne fungal contamination in the environment is a main objective of the wards in which patients at risk for INA are hospitalized.2 Recently, 2 different mobile air-decontamination units were evaluated for their protection of immunosuppressed patients against airborne contamination: Plasmair3,4 and Immunair5 (AirInSpace, Sterling, VA). These 2 units use the same novel technology to destroy airborne microorganisms. Sixt et al3 and Sautour et al4 showed that the mobile Plasmair unit reduces indoor fungal contamination and may help reduce spore load during renovation work. The unit has 3 modes
From Parasitology and Mycology Laboratory,a Hospital Hygiene Unit,b and Hematology,c Grenoble Universitary Hospital and Joseph Fourier University, Grenoble, France. Address correspondence to Marie-Pierre Brenier-Pinchart, MD, PhD, Parasitologie-Mycologie, Poˆle de Biologie, Centre Hospitalier Universitaire, BP 217, 38043 Grenoble Cedex 9, France. E-mail: MPBrenierPinchart@ chu-grenoble.fr.
0196-6553/$36.00 Copyright ª 2009 by the Association for Professionals in Infection Control and Epidemiology, Inc. doi:10.1016/j.ajic.2008.12.006
680
of activity, corresponding to different situations: ‘‘activity mode’’ (1000 m3/hour; 59 dB), ‘‘day mode’’ (650 m3/ hour; 51 dB), and ‘‘night mode’’ (450 m3/hour; 44 dB). The effectiveness of this mobile air-treatment system used at a high aspiration flow rate was demonstrated in one hematology ward of our hospital,6 but some adult patients complained of excessive noise when staying for long periods in a room in which this device was in use. The objective of our study was to prospectively evaluate the reduction in fungal contamination from the use of the Plasmair mobile air-decontamination unit at a low aspiration flow rate (450 m3/hour) during the day in the absence of care, with this function being less noisy for the patients. Between July 24, 2006 and September 1, 2006, the air and surface fungal contamination of 18 rooms equipped with Plasmair and 18 rooms without specific air treatment (conventional rooms) were studied in 2 adult hematology wards, designated WA and WB. In these wards, partial air control was provided by airconditioning with 85% central opacimetric filtration. Hematology ward WA included 7 beds (in 6 patient rooms); the nursing staff had attended specialized training, and the main unit entrance had a door that closed automatically. Hematology ward WB had 21 beds (in 13 patient rooms) with a main entrance door that did not close automatically and was closed less systematically. WA had 1 Plasmair unit, and WB had 2 Plasmair units. The patients with
Brenier-Pinchart et al.
www.ajicjournal.org Vol. 37 No. 8
681
measured in rooms with the Plasmair unit operated at a low aspiration flow rate was counted. We found that the mobile Plasmair unit used at a low aspiration flow rate (night mode) significantly reduced indoor fungal contamination of air and surfaces in the 2 hematology wards. Under our study conditions, the fungal loads measured in rooms equipped with a Plasmair unit were lower than those reported by Sixt et al,3 but higher than those measured previously in the air of these wards with the Plasmair unit operated at a high aspiration flow rate (ie, 0.85 CFU/m3).6 Furthermore, Sixt et al3 did not distinguish among the Plasmair unit’s 3 modes of activity. But although no agreement exists as to the spore concentration threshold at which a significant risk of invasive fungal infections occurs,8 the FF level obtained in our conditions cannot be considered sufficiently low to allow any risk of FF contamination to be ruled out. We also cannot disregard the importance of other preventive measures that should be associated with the use of the Plasmair unit. WA and WB used different behavioral practices aimed at invasive filamentous fungal infections prevention. The FF load in the corridors was much higher in WB than in WA, in which the preventive measures were more drastic. This difference also was found in conventional rooms, with a more significant reduction in overall fungal contamination in WA than in WB. Since the end of our study, a new Plasmair device has become available with higher aspiration flow rates (500 to 2000 m3/h) and a clear improvement in noise level (1000 m3/h; 47 dB). This new model is as silent at a high aspiration flow rate as the model that we used in the night mode. In conclusion, the Plasmair mobile air-decontamination unit may be helpful in reducing fungal spore load, but its preferred mode of operation is at a high aspiration flow rate. The use of other preventive measures is necessary to limit the entry of spores in rooms equipped with this unit. The Plasmair unit also may be proposed in other wards besides hematology
agranulocytosis were hospitalized in rooms in which the Plasmair unit was associated with preventive measures. Nine surface samples per room were obtained using contact plates (Merck KGaA, Darmstadt, Germany), and 1 m3 of air per room was collected with an Air Ideal 90-mm biocollector (bioMe´rieux, Marcy L’Etoile, France) (2 3 500 L, placed 1 m away from the bed) loaded with Sabouraud chloramphenicol plates (AES Chemunex, BRUZ Cedex, France). In addition, 1 m3 of air was collected in the corridor of each unit. All samples were incubated at 278C for 7 days. Filamentous fungi (FF) were counted as colony-forming units (CFU) per plate or per m3 of air and identified based on their macroscopic and microscopic characteristics.7 Species identification was performed for Aspergillus fumigatus. The number of CFU per m3 or per room was evaluated for significance by Student’s t-test using Statview software (SAS Institute, Cary, NC). During this 6-week prospective study, 324 surface samples and 72 air samples (36 m3) were studied in 36 rooms. FF was found in 49 surface samples (mean level, 2.4 6 3.2 CFU/room) and in 62 air samples (mean, 9.8 6 12.4 CFU/m3). A mean FF level of 17.5 6 12.9 CFU/m3 was found in the corridors. Overall, the level of FF contamination was significantly higher in WB than in WA (3.3 6 3.6 CFU/room in WB vs 0.6 6 1.1 CFU/room in WA for surface samples; 12.9 6 14.1 CFU/m3 in WB vs 3.8 6 3.7 CFU/m3 in WA for air). A fumigatus was isolated on only 3 occasions in the air of the conventional rooms (1 room in WA and 2 rooms in WB) and never in any of the Plasmair-treated rooms. In both WA and WB, a significant reduction was observed in the overall fungal contamination of surfaces and air in rooms in which the Plasmair unit was used at a low aspiration flow rate compared with conventional rooms (Table 1). The Plasmair-equipped rooms displayed decreases in FF load of 86% in surface samples and 80% in air samples compared with nonequipped rooms. However, the decontamination was not total, since a mean FF load of 3.2 6 2.8 CFU/m3 of air
Table 1. Mean (6 SD) fungal load of air and surface collected in rooms treated or not treated with Plasmair at low flow (450 m3/h) in 2 hematology wards Rooms
Corridors 3
Surface, CFU/room
WA (12 rooms) WB (24 rooms) Total
Air, CFU/m3
Air, CFU/m
Plasmair treatment (n 5 162)*
No air treatment (n 5 162)
Plasmair treatment (n 5 18 m3)
No air treatment (n 5 18 m3)
(n 5 18 m3)
0y 0.8 6 0.7y 0.6 6 0.7y
1.2 6 1.3 5.8 6 3.5 4.3 6 3.7
1.5 6 0.5y 4 6 3.2y 3.2 6 2.8y
6.2 6 4.1 21.7 6 15.4 16.5 6 14.7
5.8 6 5.4 23.1 6 12 17.5 6 12.9
*Number of contact samples. y P , .05 (Plasmair treatment vs no treatment).
682
Brenier-Pinchart et al.
wards, because of the presence of INA in patients hospitalized in these wards as well.9 We thank S. Durville for rereading the manuscript and also thank the nursing staff of the 2 hematology wards.
References 1. Alberti C, Bouakline A, Ribaud P, Lacroix C, Rousselot P, Leblanc T, et al. Relashionship between environmental fungal contamination and the incidence of invasive aspergillosis in haematology patients. J Hosp Infect 2001;48:198-206. 2. Tablan OC, Anderson LJ, Besser R, Bridges C, Hajjeh R. Centers for Disease Control and Prevention, Healthcare Infection Control Practices Advisory Committee. Guidelines for preventing health-care-associated pneumonia, 2003: recommendations of the CDC and the Healthcare Infection Control Practices Advisory Committee. MMWR Morb Mortal Wkly Rep 2004;53:1-36. 3. Sixt N, Dalle F, Lafon I, Aho S, Couillault G, Valot S, et al. Reduced fungal contamination of the indoor environment with the Plasmair system (AirInSpace). J Hosp Infect 2007;65:156-62.
American Journal of Infection Control October 2009 4. Sautour M, Sixt N, Dalle F, L’Ollivier C, Calinon C, Fourquenet V, et al. Prospective survey of indoor fungal contamination in hospital during a period of building construction. J Hosp Infect 2007;67: 367-73. 5. Poirot JL, Gangneux JP, Fisher A, Malbernard M, Challier S, Laudinet N, et al. Evaluation of a new mobile system for protecting immune-suppressed patients against airborne contamination. Am J Infect Control 2007;35:460-6. 6. Reboux G, Poirot JL, Mallaret MR, Labrousse H, Descamps F, Sixt N, et al. Prevention of airborne fungal infection and cross-contaminations using the Plasmair unit. In Proceedings of the Congress of the International Society for Human and Animal Mycology, 2006; abstract P-0303. 7. Faure O, Fricker-Hidalgo H, Lebeau B, Mallaret MR, Ambroise-Thomas P, Grillot R. Eight-year surveillance of environmental fungal contamination in hospital operating rooms and hematological wards. J Hosp Infect 2002;50:155-60. 8. Munoz P, Burillo A, Bouza E. Environmental surveillance and other control measures in the prevention of nosocomial fungal infections. Clin Microbiol Infect 2001;7:28-45. 9. Fourneret-Vivier A, Lebeau B, Mallaret MR, Brenier-Pinchart MP, Brion JP, Pinel C, et al. Hospital-wide prospective mandatory surveillance of invasive aspergillosis in a French teaching hospital (2000-2002). J Hosp Infect 2006;62:22-8.