Maintaining a safe environment: cleaning and disinfection Dr Tim Boswell Consultant Medical Microbiologist Infection Control Doctor Nottingham University Hospitals
Evidence that a contaminated environment is important in hospital infections
Environmental contamination and healthcare associated infections Role of the environment in cross-infection has been debated for many years However there is increasing evidence and consensus that environmental contamination can make an important contribution to hospital infection Several recent review articles have been published looking at the evidence regarding: MRSA VRE Clostridium difficile Norovirus Acinetobacter References: Boyce J. Environmental contamination makes an important contribution to hospital infection. J Hosp Infect (2007) 65(S2): 50-54. Dancer SJ. Importance of the environment in MRSA acquisition: the case for hospital cleaning. Lancet Infectious Diseases (2007) Weber DJ et al. Role of hospital surfaces in the transmission of emerging healthcare-associated pathogens. (2010). In: Disinfection, Sterilization and Antisepsis. Rutala WA (Ed), APIC.
Environmental contamination and nosocomial infection MRSA Survives very well in the environment Surfaces/equipment readily become contaminated (up to 60% in some studies) Hands/gloves of HCWs can become contaminated even when not directly touching patients Outbreaks halted once enhanced cleaning introduced Prior room occupancy with MRSA is a risk for acquisition C.difficile Convincing evidence of the role of the contaminated environment Survives very well in the environment Risk of HCW hand contamination linked to level of environmental contamination Risk of C.difficile increases if housed in the same room as a previous C.difficile patient Improved room decontamination reduces infection risks
Evidence that routine cleaning & disinfection of the hospital environment and equipment is often ineffective against nosocomial pathogens
UV-visible marker showing failure of terminal cleaning in 23 acute care hospitals Prospective multicentre study Defined high risk objects in patient isolation rooms marked with UV-M prior to cleaning Overall 49% of objects/surfaces were not cleaned (range 35-81% Wide variation in cleaning particular items esp poor were toilet handles, bedpan cleaners, light switches and door handles Carling PC et al. Identifying opportunities to enhances environmental cleaning in 23 acute care hospitals. Infect Control Hosp Epidemiol (2008) 29:1-7
UV-visible marker demonstrating lack of compliance with cleaning protocols UVM applied to toilets and commodes Invisible in natural light, water soluble, readily removed Inspected daily and sampled for C.difficile 102 toilet samples and 32 commode samples from 10 patients with CDAD UVM marker found in 50/102 toilet samples (49%) and 23/32 (72%) commode samples Toxigenic C.difficile recovered from 33% toilet samples and 62% of commode samples Alfa M et al. UV-visible marker confirms that environmental persistence of Clostridium difficile spores in toilets of patients with C.difficileassociated diarrhea is associated with lack of compliance with cleaning protocol. BMC Infectious Diseases (2008) doi:10.1186/1471-2334-8-64
Failure to decontaminate MRSA by conventional cleaning (detergent sanitizer) French GL et al. Tackling contamination of the hospital environment by MRSA: a comparison between conventional terminal cleaning and hydrogen peroxide vapour decontamination. J Hosp Infection (2004) 57: 31-37
Failure to decontaminate MRSA by terminal cleaning in an open plan ICU Hardy et al. Rapid decontamination with MRSA of the environment of an ICU after decontamination with hydrogen peroxide vapour. J Hosp Infect (2007) 66:360-368.
Norovirus Hospital wide outbreak 2009-2010 326 patients, 22 wards 56 confirmed cases 8 distinct genetic clusters of genotype GII-4 Cleaning with Actichlor plus (1000 ppm) Environmental sampling post cleaning 75 of 239 samples were positive by RT-PCR (31.4%) 45% of soap/alcohol gel dispensers 46% of patient equipment 30% sites at nurses station (notes trolley, computer keyboards) 2 wards were re-cleaned Contamination fell from 42% to 13% and 49% to 19% Approx 1 log reduction as determined by PCR cycle first positive Morter S et al. Norovirus in the hospital setting: virus introduction and spread within the hospital environment. J Hosp Infection (2010) doi:10.1016/j.jhin.2010.09.035
Effect of cleaning with 1% hypochlorite on environmental contamination with Clostridium difficile* Before Cleaning After Cleaning Number of Surfaces Positive for C.difficile 12 / 20 10 / 20 Total Number of Colony Forming Units 27 18 Percentage of Surfaces Found to be Positive 60% 50% *Boswell (2008, unpublished data)
Evidence that patients can acquire MDROs from the previous room occupant via a contaminated environment
Prior room occupancy as a risk factor for Gram-positives Retrospective cohort study of 8 ICUs Routine admission and weekly screening for MRSA and VRE Previous MRSA and VRE occupancy increased risks of MRSA and VRE acquisition (OR 1.4, p=0.04 and 0.02) Cohort study in 2 ICUs Risk of VRE acquisition increased if prior room occupant was VRE, any room occupant in previous 2 weeks was VRE, or previous environmental room cultures were positive Huang SS et al. Risk of acquiring antibiotic-resistant bacteria from prior room occupants. Arch Intern Med (2006) 166: 1945-1951. Drees M et al. Prior environmental contamination increases the risk of acquisition of vancomycin-resistant enterococci. Clin Infect Dis (2008 46: 678-85.
Prior room occupancy as a risk factor for C.difficile Retrospective cohort study of medical ICU 87 patients with CDI compared to 1682 controls 77 out of 1679 patients developed CDI who were not exposed to rooms where previous occupant had CDI (4.6%) 10 out of 91 patient developed CDI who were exposed to rooms where previous occupant had CDI (11.0%) Multivariate analysis showed that this risk remained after other CDI risk factors were controlled for Strachan L et al. Evaluation of hospital room assignment and acquisition of Clostridium difficile infection. Infect Control Hosp Epdemiol (2011) 32: 201-206
Prior room occupancy as a risk factor for Gram-negative rods Study setting 30 isolation ICU rooms Prospective observational cohort study of 511 patients Routine surveillance for MDR Gram negatives (coliforms, Acinetobacter, Pseudomonas) Results (multivariate analysis) Prior room occupation with an MDR GNB was a risk for Ps.aeruginosa OR 2.3 (1.2-4.3) p=0.012 A.baumanii OR 4.2 (2-8.9) p<0.001 Environmental cultures not done but time to acquisition of the above was significantly shorter that n for ESBLs, where the was no association with prior room occupancy Nseir S et al. Risk of acquiring multidrug-resistant Gram-negative bacilli from prior room occupants in the intensive care unit. Clinical Microbiology and Infection (2010)
The risk of acquiring a MDRO from the previous room occupant is reduced by HPV room decontamination compared to standard manual cleaning 30 month prospective study Prior room occupant was infected or colonized with MDRO in 22% of 6350 admissions. Patients admitted to rooms decontaminated using HPV were 64% less likely to acquire any MDRO (incidence rate ratio [IRR]=0.36, CI=0.19-0.70, p<0.001) and 80% less likely to acquire VRE (IRR=0.20, CI=0.08-0.52, p<0.001) after adjusting for other factors. The risk of acquiring Clostridium difficile, methicillin-resistant Staphylococcus aureus and multidrug-resistant Gram-negatives individually was reduced, but not significantly. The proportion of rooms environmentally contaminated with MDROs was reduced significantly on the HPV units (relative risk=0.65, p=0.03), but not on non-hpv units. Passaretti et al. An evaluation of environmental decontamination with hydrogen peroxide vapor for reducing the risk of patient acquisition of multidrug-resistant organisms. Clin Infect Dis (2013)
Area/room decontamination technologies
Overview of area decontamination technologies
Gaseous hydrogen peroxide v C.difficile in patient isolation rooms Shapey et al. Activity of a dry mist hydrogen peroxide system against environmental Clostridium difficile contamination in elderly care wards. J Hosp Infect (2008) 70:136-141
Comparison of gaseous H 2 O 2 and hypochlorite against C.difficile Hypochlorite H 2 O 2 Barbut F et al. Comparison of the efficacy of a hydrogen peroxide dry-mist disinfection system and sodium hypochlorite solution for eradication of C.difficile spores. Infect Cont Hosp Epidemiol (2009) 30:507-514
Efficacy of whole ward hydrogen peroxide decontamination against C.difficile 30 bed stroke rehab unit with endemic CDI problem Immediately following decant Following deep-clean with Chlor-Clean Following hydrogen peroxide decontamination 19 days later (ward re-occupied) Number of samples Number +ve for Cdiff Comments 342 37 (10.8%) Ribotypes 001/072, 014, 078, 046 342 21 (6.2%) 6 trained personnel over 1 week, whole ward decanted Ribotypes 078, 014, 046 342 3 (0.9%) Ribotype 001/072 342 0 (0%) 20 weeks later 342 12 (3.5%) Mostly ribotype 002 from 1 patient with CDI Best et al. Effectiveness of deep cleaning followed by hydrogen peroxide decontamination during high Clostridium difficile infection incidence. J Hosp Infect (2014) 87: 25-33.
Index Patient 4 Burns ward MRA outbreak in 2008 Oxa-58 carbapenemase Index case transferred from ITU in Greece Patient 2 ITU Burns ward Patient 1 ITU Burns ward Patient 3
Detection of MRA in the burns operating theatre air
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Incidence of new MRA cases Incidence of MRA on the Nottingham Burns Unit 12 10 Hydrogen peroxide decontamination of burns theatre suite 8 6 Hospital acquired Imported 4 2 0
Summary & conclusions Good evidence that hospital infections can be transmitted from a contaminated environment (MRSA, VRE, C.difficile, norovirus, MDR GNBs) Traditional manual cleaning/disinfection, including terminal cleaning, is often only 50% effective There is a clear risk of acquiring MDROs (both Gram positive and Gram negative) from previous room occupants Automated room decontamination systems can significantly improve room decontamination and reduce the risks of patients acquiring key pathogens from the environment