longitudinal risk assessment of a paediatric bone marrow transplant unit for pathogenic fungi...
TRANSCRIPT
Longitudinal Risk Assessment of a Paediatric Bone Marrow Transplant Unit for Pathogenic Fungi
Longitudinal Risk Assessment of a Paediatric Bone Marrow Transplant Unit for Pathogenic Fungi
Malcolm Richardson PhD, FIBiol, FRCPath
University of Helsinki
MoBiAir Diagnostics Ltd
Malcolm Richardson PhD, FIBiol, FRCPath
University of Helsinki
MoBiAir Diagnostics Ltd
The fungi: What a team!The fungi: What a team!
The background: Children’s HospitalThe background: Children’s Hospital Before renovation: incidence of IFI:
allogeneic stem cell Tx recipients: 16% autologous stem cell Tx recipients: 8%
Renovation/interventions: air ventilation improvements two-door isolation rooms HEPA filtration
After renovation: allogeneic SCT: 3.2% incidence autologous SCT: 0%
Before renovation: incidence of IFI: allogeneic stem cell Tx recipients: 16% autologous stem cell Tx recipients: 8%
Renovation/interventions: air ventilation improvements two-door isolation rooms HEPA filtration
After renovation: allogeneic SCT: 3.2% incidence autologous SCT: 0%
Double door entryDouble door entry
Ceiling tilesCeiling tiles
Aspergillus fumigatusAspergillus fumigatus
BlankophorBlankophor
© G. Armstrong, © G. Armstrong, Hope Hospital, Hope Hospital, Manchester Manchester © O. Zimmerman and R. Ruchel, Gottingen, Germany© O. Zimmerman and R. Ruchel, Gottingen, Germany
Growth of Aspergillus
1-2 mm per hour1-2 mm per hour
EORTC EORTC IFICGIFICG
DEVELOPMENT OF ASPERGILLOSISDEVELOPMENT OF ASPERGILLOSIS
11 22 33
INHALATIONINHALATION INFECTIONINFECTIONCOLONIZATIONCOLONIZATION Dissemination
Dissemination
Invasive Aspergillus infectionsInvasive Aspergillus infections
Sources of Aspergillus spp.Sources of Aspergillus spp.
Environment: air, dust Food
Long list! Sharing of salt and pepper pots
Standing water Showers Ice-making machines Fomites
Carpets/furniture/fabrics/soft toys
Environment: air, dust Food
Long list! Sharing of salt and pepper pots
Standing water Showers Ice-making machines Fomites
Carpets/furniture/fabrics/soft toys
Aspergillus is in the air Aspergillus is in the air
Aspergillus is in the airAspergillus is in the air
Aspergillosis and building worksAspergillosis and building works
Wald et al. J Infect Dis 1997;175:1459
0.00.0
1.01.0
2.02.0
3.03.0
4.04.0
5.05.0
6.06.0
7.07.0
AbsentAbsent PresentPresent
%%
Acceptable levelsAcceptable levels
HEPA filtered air: 0 Open ward:? General hospital areas: ? Outdoor air: highly variable/seasonal
HEPA filtered air: 0 Open ward:? General hospital areas: ? Outdoor air: highly variable/seasonal
Invasive aspergillosis related to construction and the utility of air samplingInvasive aspergillosis related to construction and the utility of air sampling
8-bedded BMT unit 2 cases of IPA 5 cases of colonisation Coincided with major construction project on
floor directly below unit High air counts before cleaning No isolation after construction stopped and deep
cleaningLai et al., 39th ICAAC, San Francisco 1999
8-bedded BMT unit 2 cases of IPA 5 cases of colonisation Coincided with major construction project on
floor directly below unit High air counts before cleaning No isolation after construction stopped and deep
cleaningLai et al., 39th ICAAC, San Francisco 1999
Assessment Assessment
Structural survey Air Surfaces Dust Water analysis Fabrics Carpets Relative humidity
Structural survey Air Surfaces Dust Water analysis Fabrics Carpets Relative humidity
Air samplingAir sampling
Objectives of air sampling 1Objectives of air sampling 1
Correlation of outbreaks with hospital construction/demolition
Identification of potential sources of nosocomial aspergillosis
Prediction of contamination from outside sources
Identification of defects/breakdown in ventilation/filtration systems
Correlation of outbreaks with hospital construction/demolition
Identification of potential sources of nosocomial aspergillosis
Prediction of contamination from outside sources
Identification of defects/breakdown in ventilation/filtration systems
Objectives of air sampling 2Objectives of air sampling 2
Monitoring of cleaning procedures Efficacy of HEPA filters in LAF rooms Monitoring of procedures to contain
hospital building work from hospital wards/single-bedded units
Monitoring of cleaning procedures Efficacy of HEPA filters in LAF rooms Monitoring of procedures to contain
hospital building work from hospital wards/single-bedded units
Dust!Dust!
Indoor dust:
Deposited over long periods of time
Will reflect long-term exposure history easy and cheap to collect
Indoor dust:
Deposited over long periods of time
Will reflect long-term exposure history easy and cheap to collect
Dust collection
Ward 9, Dust
0
2
4
6
8
1 2 3 4 5 6 7Weeks
CFU
K9/1 K9/2 K9/3 K9/4 K9/5K9/6 K9/7 K9/8 K9/9 K9/10
Is invasive aspergillosis community-acquired?Is invasive aspergillosis community-acquired?
Up to 70% of cases community-acquired?
Hospital environmental control measures will not influence community-acquired cases
Control/preventative measures Surveillance of home environments Prophylaxis with antifungal drugs
Up to 70% of cases community-acquired?
Hospital environmental control measures will not influence community-acquired cases
Control/preventative measures Surveillance of home environments Prophylaxis with antifungal drugs
Days after transplantDays after transplant
1010 2020 3030 4040 5050 6060 7070 8080 9090 100100 110110 120120 130130 140140 150150 160160 170170
Cases
Cases
2020
1818
1616
1414
1212
1010
88
66
44
22
00
Wald et al. J Infect Dis 1997;175:1459(modified by J.P. Donnelly)
Aspergillus: Time to diagnosis of aspergillosis after BMTAspergillus: Time to diagnosis of aspergillosis after BMTNeutropeniaNeutropenia
Graft versus host Graft versus host diseasedisease
Late onset of IA in BMT patients at a university hospitalLate onset of IA in BMT patients at a university hospital
93 allogeneic and 149 autologous pts 20 month period 0% IA autologous 15.1% allogeneic: overall incidence 5.8% Median time to occurrence: 92 days No de novo cases prior to engraftment Survival 100 days from diagnosis 29% Conclusions
shift towards late occurrence outpatient environment surveillance
Grow et al., BMT 2002; 29: 15-19
93 allogeneic and 149 autologous pts 20 month period 0% IA autologous 15.1% allogeneic: overall incidence 5.8% Median time to occurrence: 92 days No de novo cases prior to engraftment Survival 100 days from diagnosis 29% Conclusions
shift towards late occurrence outpatient environment surveillance
Grow et al., BMT 2002; 29: 15-19
Surveillance of the home environmentSurveillance of the home environment
Patients live in mouldy houses:exposure to Aspergillus and morePatients live in mouldy houses:exposure to Aspergillus and more
ConclusionsConclusions
Strong association between building renovation and an increase in environmental contamination
Many studies confirm the value of the high efficacy of laminar airflow plus HEPA filtration and a high air-exchange rate
HEPA filtration alone did not prevent contamination during renovation
A standard protocol for aerobiological surveillance is needed
Strong association between building renovation and an increase in environmental contamination
Many studies confirm the value of the high efficacy of laminar airflow plus HEPA filtration and a high air-exchange rate
HEPA filtration alone did not prevent contamination during renovation
A standard protocol for aerobiological surveillance is needed
A deadly dust may be blowing in the wind during renovationsA deadly dust may be blowing in the wind during renovations
Hospital infection control
Deaths – despite aggressive control measures ??Community-acquired aspergillosis Put guidelines in the contract One death should prompt inquiry Water may be source of Aspergillus Conduct regular walk-throughs
Hospital infection control
Deaths – despite aggressive control measures ??Community-acquired aspergillosis Put guidelines in the contract One death should prompt inquiry Water may be source of Aspergillus Conduct regular walk-throughs
Prevention is better than cureAvoid exposure in the hospital and in the homePrevention is better than cureAvoid exposure in the hospital and in the home