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): 5054. 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 3581% • 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