cleaning

How can we stop nursing homes nurturing MRSA?

Jon Otter (@jonotter) MRSA , , , , , ,

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There is an emerging feeling that we need to start spreading the focus of infection prevention and control beyond acute hospitals. There has always been a sense that standards of infection control outside of acute settings are, shall we say, “different” to acute hospitals (aka non-existent) so it’s great to see a study of an infection control intervention in nursing homes.

The study was a cluster randomised controlled trial of MRSA screening, decolonisation and enhanced environmental disinfection vs. standard precautions in 104 of 157 nursing homes in a Swiss region. The authors chose a rather unusual, pragmatic endpoint of the prevalence of MRSA colonisation after 12 months.

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What’s lurking in the hospital environment? The importance of cleaning and disinfection in infection prevention and control

Jon Otter (@jonotter) Environment , , ,

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I was asked to speak to a group of link nurses at Southampton Hospital earlier in the week, and thought I’d share my slides, here.

I am passionate about the importance of surface contamination in transmission: I still think it’s really under-rated. I am pretty sure that most healthcare workers would have no idea that your chances of acquiring C. difficile infection (and others) is influenced by who used the room or bed space before you. And who would believe that VRE could survive on a dry surface for 4 years? Or that touching a surface is as important as touching the patient in terms of acquiring contamination on your hands?

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Probiotics for environmental cleaning – can’t B. cereus

Andreas Voss (@AVIPNL) Disinfection , , ,

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Vandini et al. (1) evaluate the effect of a microbial cleaner, containing spores of food grade Bacillus subtilis, Bacillus pumilus and Bacillus megaterium in two Italian and one Belgium hospital.

According to the abstract 20,000 microbiological samples were taken from surfaces, during the 24-week investigation, which would equal approximately 120 samples per day!

While nothing about blinding or block-randomization (or any possible approach that would eliminate bias) was mentioned, it is stated that the cleaning staff was not aware which cleaning product they used. Seen the fact that chlorine based-cleaners were the standard products in the two Italian hospitals, this seems hard to believe. The study period started at different times in the hospitals (but not by design) and in opposite to the abstract for different periods of time, namely 6, 24, and 66 weeks, respectively.

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Is deliberately seeding hospital rooms with Bacillus spores a good idea? No, I don’t think so either!

Jon Otter (@jonotter) Contamination , ,

A fascinating Italian/Belgian multicentre study introduces us to the idea of “biocontrol” for problematic surface contamination. They test using “live” cleaning products that deliberately seed hospital surfaces with Bacillus species spores in an attempt to reduce the ecological space for pathogenic microbes through a “competitive exclusion” approach. Ridiculous as it sounds, there’s some logic to this idea. We’re just beginning to understand the potential of complementing a depleted microbiome in human health, so perhaps the same theory goes for the “environmentome”?

The study design is on the one hand impressive and ambitious, with more than 20,000 surfaces samples collected from the three hospitals. However, it is also messy and confusing, with different intervention and sampling protocols in the three hospitals. In particular, it’s a real shame that areas were not randomized to receive the “live” vs. conventional cleaning agents. It seems clear that this was not a carefully planned multicentre study using a standardized protocol – it reads more like three separate studies shoe-horned together.

That said, the results are impressive. Areas treated with the “live” cleaning agents were significantly less likely to be contaminated with coliforms, S. aureus, Candida albicans, with a more moderate impact on C. difficile. However, it’s difficult to determine the scale of the reduction since the relative rather than actual load reductions are reported.

A neat sub-experiment at one of the hospitals is perhaps the most convincing part of the study, where conventional and “live” cleaning agents were alternated (Figure). You can clearly see that the microbial load tracked downwards when the “live” agent was used, and rebounded when the conventional agent was reinstated.

vandini bacillus sporesFigure: Bacterial load of coliforms (black circles) and S. aureus (white circles). Black arrow = beginning of the “live” cleaning agent; black dotted arrow = conventional cleaning agent.

Notwithstanding the impressive reductions, this approach is ringing some alarm bells:

  • Do we really know what we’re doing by deliberately seeding the hospital environment with bacterial spores? Almost all microbes can be pathogenic to immuno-compromised patients. Plus, whilst you know what you’re putting down, you don’t know what it will become when exposed to the selective pressure of hospitals. The authors did take a look at this, using antibiotic susceptibility testing and a PCR assay to show that Bacillus species identified from the original cleaning agents and from hospitals surfaces during study did not differ in their carriage of antibiotic resistance genes. However, this is only scratching the surface of a complex risk.
  • Where do all the pathogens go? Having an environment that is full of Bacillus spores does not make a scrap of difference to the amount of pathogens that are shed into the environment. So, either the Bacillus spores somehow reduce the amount of time that these pathogens survive on surfaces, or offer them a more complex hiding place. I suspect the latter is more likely.
  • Related to this, recent work has identified established biofilms on dry hospital surfaces with important implications. Won’t a daily dose of Bacillus spores only serve to promote the buildup of this biofilm?
  • The authors proffer some potential reasons for the lower bacterial counts, including competition for nutrients and quorum sensing to destabilize biofilms. I think these are very unlikely, because they rely on the Bacillus spores germinating on the surfaces. I suspect that the spores remain firmly as spores, and the reductions are explained by occlusion and competition for space.
  • Ethics can be a pain, but it’s there for a reason – to prevent our patients from unnecessary harm. The outcome of their ethical submission was surprising: “The two Ethics Committees stated that a formal authorization was not necessary because the probiotic products would not be directly administered to patients but exploited for cleaning of hospital surfaces only.” Applying a soup of Bacillus species spores to a patient’s room is pretty much the same thing as applying the soup directly to their skin. Personally, I’d like to choose whether or not I’m admitted to a room deliberately seeded with Bacillus spores!
  • The authors insist on calling the “live” cleaning agents ‘probiotics’, which seems misplaced. To me, ‘xxx-biotics’ implies something that is administered to a patient.

The use of “live” cleaning agents provides an interesting alternative approach to antimicrobial surfaces, or chemicals with residual biocidal activity. However, I am not sure I accept the authors stark choice as their final conclusion: ‘When it comes down to risk management, one has to decide whether a patient should stay in an environment dominated by food grade microorganisms or in an environment harboring an elevated level of increasingly resistant pathogens.’ Personally, I’d prefer to be cared for in an environment with minimal levels of bacterial contamination, and free from contamination with pathogens. Is that too much to ask?

Article citation: Vandini et al. Hard Surface Biocontrol in Hospitals Using Microbial-Based Cleaning Products. PLoS One 2014;9:e108598.

Reflections from HIS 2014, Part II: Dealing with the contaminated environment

Jon Otter (@jonotter) Conferences , , , , , , ,

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Welcome to Part II of my reflections from HIS. For the box-set, see the list at the beginning of Part I here.

Dr Karen Vickery – Multispecies biofilms on dry hospital surfaces – harbouring and protecting multiantibiotic resistant organisms

Probably the most important update from the entire conference was more data from the Vickery lab on biofilms on dry hospital surfaces. She excised 44 dry surface samples from the ICU, put them under the electron microscope and, lo and behold, 41 of them (93%) had fully-fledged (if somewhat unusual) EPS-producing biofilms on! The implications are huge: this could explain extended surface survival, poor success rate of surface sampling, and result in reduced biocide susceptibility up to the tune of 1000x (see my review just published in JHI with Karen as a co-author for more on biocides and biofilm susceptibility).

Dr Silvia Munoz-Price – Controlling multidrug resistant Gram-negative bacilli in your hospital: We can do it so can you!

Dr Munoz-Price described her hospital’s impressive reductions on carbapenem-resistant A. baumannii – from 12 new isolates per week to virtually none today. So what worked? It’s difficult to be sure since it was a bundled intervention. Dr Munoz-Price described the rationale behind some elements of the bundle: environmental surface and staff hand sampling to visualize the invisible, environmental cleaning and disinfection to deal with the ‘fecal [sic] patina’ [a stooly veneer emanating from the rectum] (see Dr Munoz-Price and Dr Rosa’s guest blog for more details), and chlorhexidine bathing. Perhaps the most interesting aspect was the various implementation challenges that were overcome. It was amazing how far removed practice ‘in the trenches’ was from the policy set by the epidemiologist’s office, exemplified by environmental staff buying their own UV lamps to for “spot cleaning” removal of fluorescent markers of cleaning thoroughness. Overcoming these challenges required more that the stick (citations for non-compliance, which failed); culture change takes understanding, time and a very large carrot (and some sticks too, sometimes).

Jim Gauthier – faeces management

A number of key pathogens are associated with faecal colonization and shedding: C. difficile, VRE, ESBL and CRE. Jim didn’t mention MRSA, but this can also cause gastrointestinal colonization and, more controversially, infection. Enterobacteriaceae can survive on dry surfaces for longer than you’d expect, too. We traditionally worry about surface contamination of high-touch sites in inpatient settings. Floor contamination isn’t important (unless you happen to be a wheel chair user, a toddler, or drop your pen). Contamination in outpatient settings isn’t a problem either (unless you happen to have a fairly short consultation for a patient with VRE). So, what to do? Jim introduced the idea of a ‘hierarchy of control’; put another way, prevention is better than cure, so do we have the right systems in place to manage faeces which is teeming with hospital pathogens? For example, should we be enforcing mandatory contact precautions for all contact with faeces (standard precautions – which aren’t very standard anyway – are probably not adequate)? Finally, Jim mentioned the growing importance of faecal microbiota transplantation (and hearing a Canadian speak about this reminded me of a hilarious spoof video).

No-touch automated room decontamination (NTD)

medical equipment in a hospital roomFigure: Hospital bed rails are frequently contaminated, and often not easy to clean and disinfect using conventional methods. 

Paul Dickens – establishing Ebola surge isolation capacity in the UK

Paul Dickens gave a whistle-stop overview of the detailed plans for Ebola surge capacity in the UK (perish the thought). He began by describing the replacement of formaldehyde with hydrogen peroxide vapour for the decontamination of the patient isolators at the Royal Free High Level Isolation Unit (HLIU). They now have a tried and tested process and protocols in place to get the HLIU back online within days using hydrogen peroxide vapour decontamination, where the previous protocol using formaldehyde put it out of action for 6 weeks! (I was involved in writing the protocols for this tricky decontamination assignment, which were reported on a poster published at HIS.) Other challenges in establishing surge capacity include staff expertise, and PPE recommendations, supply & training. Surge capacity is now established. Let’s just hope we won’t need it!

Dr Frédéric Barbut – How to eradicate Clostridium difficile spores from the environment

There’s now plenty of evidence that contaminated surfaces contribute to the transmission of C. difficile. These environmental intervention studies show a 50-80% reduction in the rate of CDI; does this mean that 50-80% of CDI acquisition is environmentally-associated? This seems too high, but it’s difficult to think of another explanation. Furthermore, there is emerging but compelling evidence of a proportional relationship between the degree of C. difficile surface contamination and transmission risk? I really don’t think that the public have yet ‘got’ that the previous occupant can influence acquisition risk. And when they do, I think there will be increasing demand for properly decontamination rooms. So, is it time to turn to NTD systems? Sometimes, yes. And do you go for hydrogen peroxide or UV? Well, that depends on what you’re trying to achieve! If you’re trying to eliminate pathogens, which sometimes you will be, then hydrogen peroxide vapour is the best choice. But if you’re trying to reduce contamination levels without necessarily eliminating all pathogens, then UV is the best choice due to its speed and ease of use.

The debate: “Hospitals that do not use high-tech decontamination of the environment are doing their patients a disservice.”

This debate pitted Profs Hilary Humphreys and Phil Carling (pro) against Peter Hoffman and Martin Kiernan (con). It was lively, entertaining and engaging…

Prof Humphreys argued that it is not acceptable to admit patients to rooms with inherent additional risk for transmission. We can address this by ‘walking like the Egyptians’ and copperising our surfaces, for which there is now some data with a clinical outcome. Another approach is NTD systems, for which data (including some clinical outcomes) are emerging. Prof Carling’s presentation was somewhat unusual, with his arguments seemingly an appeal to common sense rather than drawn from the published literature.

Martin Kiernan began by acknowledging the role of the environment, but that hand contamination is almost always the final vector (and there’s some evidence for this). The cornerstone of Martin’s argument was that whether NTD systems work is the wrong question. We should be focusing our time, money and attention on improving conventional methods which have been shown to reduce transmission. Peter Hoffman complemented Martin’s pragmatic viewpoint with thorough, thoughtful critiques of the studies on HPV decontamination with a clinical outcome. The 2008 Boyce study has more holes than the 2013 Passaretti study, which itself is far from watertight!

The key argument for turning to NTD systems is that admission to a room previously occupied by a patient with an MDRO increases the risk of acquisition due to residual contamination, and NTD decontamination mitigates this increased risk. So, my own conclusion is that hospitals that do not use high-tech decontamination of the environment are indeed doing their patients a disservice. Sometimes!

Look out for the third and final installment of my reflections from HIS 2014 at some point tomorrow!

Image: Medical equipment in a hospital room.

What do we mean by ‘cleaning’ and ‘disinfection’?

Jon Otter (@jonotter) Contamination, Disinfection , , , ,

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We urgently need to decide what we mean when we use the terms “clean” and “cleaning”.

In the last few years, the accumulated microbiological and epidemiological data (and prolonged heated debate) has lead us to conclude that  environmental surfaces need to be considered alongside hands, laundry etc so on, as part of a multibarrier approach to infection prevention and control in healthcare settings, and hygiene at home. Set against this however, our current approach of “what do we do to these surfaces to break the chain of infection transmission?” is both unscientific, and also highly misleading to the people we need to communicate with.  This part of the equation is fast becoming the weak link, preventing us from maximising health benefits from infection prevention and control measures.  This really hit home on reading the different contributions to the excellent 2013 AJIC supplement by Rutala and Webber which, on one hand showed just how much our thinking about environmental surface risks  has developed, but in many papers “environmental cleaning” was used interchangeably with “environmental disinfection” which made it confusing to know what the writer really meant.

From our IFH experience of home hygiene, we know what happens when advising consumers (or equally, hospital cleaning staff) to “clean” a surface e.g. after preparing raw poultry. They will clean until the visible dirt is gone – and we know that this is not necessarily enough.  For the home, we have data showing that after cleaning kitchen surfaces with soap and water following preparation of a chicken (in the UK 60% are contaminated with Campylobacter),  surfaces may LOOK squeaky clean, but the Salmonella or Campylobacter is now spread everywhere (and in numbers up to 103 or more).   We have similar data for surfaces contaminated with norovirus-containing faecal matter from an infected person (for which the infectious dose may be very small).

As a start, we need a term to advise/communicate “this surface needs to be cleaned to a level that breaks the chain of infection” and we currently have NO way to do this.   If we accept that the term “clean” means absence of visible dirt/soil, we need a term to describe “microbiologically safe clean”, not just for consumers or hospital cleaning professionals, but also for communicating with each other as scientists.

There is also another common misconception. Some people work on the basis that “clean” means visibly clean, and “microbiologically safe clean” means a chemical or thermal disinfectant has been used.  But then how can we communicate that hand washing can make hand surfaces microbiologically safe” without need for a disinfectant.  There is a notion that “cleaning” is hygienically inferior to disinfection – but data now shows that the log reduction by handwashing with soap can be equivalent to that achieved by alcohol handrubs if done properly, and you have access to running water.  We put much effort into hand hygiene compliance, but relatively little into stressing that handwashing technique to deliver hands which are “fit for purpose” is equally important.

We need to go back to the simple principles of what we are trying to achieve – namely to break the chain of onwards transmission of pathogens by treating surfaces (hands or environmental) to reduce germs to an “acceptable level” i.e. make a surface “fit for purpose”.  This can be done in 2/3 ways – removing them, inactivation, or a combination of both. For the last 14 years, IFH has successfully used the word “hygienically clean” to mean “microbiolgically safe”, and “hygienic cleaning”  to describe the process to achieve this – which could be soap and water with rinsing – or cleaning disinfection, or a combination of both.

Guest Blogger Bio

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Dr Sally Bloomfield is an Honorary Professor at the London School of Hygiene and Tropical Medicine. She is also is the Chairman and Member of the Scientific Advisory Board of the International Scientific Forum on Home Hygiene (IFH).  Through these roles Professor Bloomfield continues to develop her work in raising awareness of the importance of home hygiene in preventing the transmission of infectious disease, and developing and promoting home hygiene practice based on sound scientific principles. She is also working to develop understanding of “hygiene issues” such as the “hygiene hypothesis” and “antimicrobial resistance”.

Professor Bloomfield’s background is in healthcare and infectious disease. She has a degree in Pharmacy, and PhD in Pharmaceutical Microbiology from the University of Nottingham. Sally was previously a Senior Lecturer in Pharmaceutical Microbiology at Kings College London (1995 – 1997) and a Hygiene Liaison manager at Unilever Research Port Sunlight UK (1997 – 2001).  She has published 100 research and review papers on the subject of home hygiene and the action and mode of action role of antimicrobial agents.

Is it time to turn to ‘no-touch’ automated room disinfection?

Jon Otter (@jonotter) Disinfection , , , , , , , ,

I gave a webinar for 3M yesterday entitled ‘Is it time to turn to ‘no-touch’ automated room disinfection (NTD)?’ It was based broadly on a recent Journal of Hospital Infection review article, and you can access the slides here.

The webinar covered:

  • The key data supporting the need for improved hospital disinfection, particularly ‘terminal disinfection’ when patients are discharged.
  • The strengths and limitations of conventional disinfection methods, particularly in terms of reliance on the operator to ensure adequate formulation, distribution and contact time of the active agent.
  • The potential benefits of introducing automation into the room disinfection process.
  • Coverage of the advantages and disadvantages of the various “no-touch” automated room disinfection systems currently available.
  • Scenarios in which NTD systems may be warranted.

To summarize the rationale for using an NTD system: enhanced conventional methods are able to eliminate pathogens from surfaces, but the inherent reliance on a human operator to ensure adequate formulation, distribution and contact time of the active agent introduces variability into the process. NTD systems remove or reduce reliance on the operator for delivering hospital disinfection. However, they do not obviate the need for cleaning, so they are designed to augment rather than replace conventional methods.

So when to consider an NTD system? The flow chart below (Figure 1) shows a decision tree for which cleaning and disinfection approach to take. Given their practical limitations, NTD systems are best suited to disinfection of a room after a patient colonized or infected with a pathogen has been discharged to protect the incoming patient from acquiring the pathogen left behind by the prior room occupant. A recent study of a hydrogen peroxide vapor (HPV) NTD system shows that patients admitted to rooms disinfected using HPV were 64% less likely to acquire any multidrug-resistant organism (MDRO) than patients admitted to rooms disinfected using standard methods when the prior room occupant had an MDRO.Flow chartFigure 1. A disinfection decision diagram for when to consider an NTD system. a) Key pathogens associated with contamination of the environment include C. difficile, VRE, MRSA, A. baumannii, P. aeruginosa and norovirus. b) All NTD systems are applied after a cleaning step to ensure that surfaces are free from visible contamination, which is unacceptable to subsequent patients and will reduce the efficacy of the NTD disinfection. c) There is limited equivocal evidence that enhanced cleaning / disinfection in a low-risk general ward setting can reduce the spread of pathogens.

Ok, so you’ve decided that you want to use an NTD system. Which one to choose? Every conference I go too seems to have more and more NTD systems on show, all with bold and often conflicting claims. There are essentially four classes of NTD system that are commonly used in hospitals:

  • Hydrogen peroxide vapor (HPV)
  • Aerosolized hydrogen peroxide (aHP)
  • Ultraviolet C (UVC)
  • Pulsed-xenon UV (PX-UV)

I asked the audience which, if any, NTD system had been used in their hospital (Figure 2). 90% of the predominantly US based audience had not used an NTD system at all, which was a surprise. In the hospitals that had used an NTD system, there was a fairly even split between HPV and the UV systems.Which systemFigure 2. Has your hospital used an NTD system and if so, which one?

Each of these systems have advantages and disadvantages, which I have tried to summarize in the following table by ranking the systems in the key categories. The hydrogen peroxide systems tend to have higher efficacy and better distribution than the UV systems. But the UV systems are faster and easier to use. Thus, there is a trade-off between efficacy / distribution and cycle time / ease of use when deciding which NTD system would be more appropriate.Comparision table Table: Comparing the key features of the four commonly used NTD systems.

In order to illustrate the challenges in choosing a) whether to use and NTD system and b) which to use, I presented the audience with three scenarios. In scenario 1, below, I was expecting most people to select ‘conventional methods’ or one of the UV systems, which have both been shown to reduce the burden of contamination without reliably eliminating pathogens. The sheer number of patients with MRSA colonization transferred or discharged from general medical wards means that the additional time for HPV may not be warranted.Scenario 1Scenario 1. What do you do when a patient who was colonized with MRSA has been discharged from a room on a general medical ward?

Scenario 2 is an occasion where you want to be sure that residual contamination has been dealt with so that the incoming susceptible ICU patient will not acquire the virtually untreatable carbapenem-resistant A. baumannii. Therefore, HPV, which is associated with the elimination of pathogens from surfaces, is a rational choice.   Scenario 2Scenario 2: What do you do when a patient who had an infection with carbapenem-resistant A. baumannii has been discharged from an ICU room?

Scenario 3 is more tricky. While the likelihood of C. difficile spore contamination argues for the higher efficacy of the hydrogen peroxide systems, the number of transfers or discharges of patients with C. difficile on a surgical unit may be high, which argues for the lesser efficacy but faster cycles from the UV systems. The majority of the audience selected HPV in this scenario, considering that the combined risk of the pathogen and specialty required the elimination of C. difficile spores from the room prior to the admission of the next patient.    Scenario 3Scenario 3: What would you do when a patient who had C. difficile infection has been discharged from a room on a surgical unit?

To summarize, the use of an NTD system to augment terminal disinfection is warranted in some circumstances. The choice of NTD system will depend on a number of factors, including efficacy, distribution, ease of use, cycle time and cost. The features of the various NTD systems make them best suited to different applications, dictated by the clinical setting and the environmental-pathogenic characteristic of the target pathogen. So, is it time to turn to NTD systems? 52% of the audience voted ‘yes’ at the start of the webinar; 74% voted ‘yes’ at the end!Initial finalFigure 3: Is it time to turn to ‘no-touch’ automated room disinfection? The audience were asked this question at the start and the end of the webinar, indicating a swing towards the affirmative!

Article citation: Otter JA, Yezli S, Perl TM, Barbut F, French GL. Is there a role for “no-touch” automated room disinfection systems in infection prevention and control? J Hosp Infect 2013;83:1-13.

The effect of closing and cleaning wards on infection rates

Jon Otter (@jonotter) Contamination, Disinfection, MRSA , , , ,

Not so long ago, the UK Government ordered a national ‘deep clean’. This prompted a fair amount of debate among experts and the public. If the NHS needed a spring clean, then does that mean that it was dirty in the first place? Perhaps. There does not seem to have been a formal evaluation of impact, but there is some rationale for closing and cleaning wards. For example, this paper from the early 1970s evaluated the impact of closing and cleaning five wards in London.

The five wards (four surgical and one medical) had an outbreak of MRSA (termed ‘cloxacillin-resistant S. aureus’). Rates of infection (termed ‘sepsis’) were monitored on the study wards before and after closing and cleaning. Wards were closed to admissions and emptied of patients. All fabrics were sent for laundering and all left over supplies were discarded. Cleaning comprised washing floors, walls and all other surfaces with hot water containing detergent; bed frames and furniture were also washed. The length of time that all this cleaning too is not specified, but I suspect it took place over several days. Crucially, staff and patients were screened for carriage of epidemic strains of S. aureus; colonised patients were not re-admitted after ward cleaning where possible.

The charts below show the impact on all infections (Figure 1), all S. aureus infection (Figure 2) and MRSA infection (Figure 3). Infection rates were compared 3 months before vs. 3 months after cleaning on Wards 1-3 and 6 months before vs. 6 months after on Wards 4 and 5. As you can see, the impact was pretty dramatic.

Noone Fig 1

Figure 1. Total infection rate (proportion of admissions infected) on the five wards before vs. after ward closing and cleaning.

Noone Fig 2

Figure 2. S. aureus infection rate (proportion of admissions infected) on the five wards before vs. after ward closing and cleaning.

Noone Fig 3

Figure 3. MRSA infection rate (proportion of admissions infected) on the five wards before vs. after ward closing and cleaning.

The poor reduction in total infection rate on Ward 1, a gynecological ward, (Figure 1) is largely due to high Gram-negative infection rates before and after cleaning, most likely explained by endogenous urinary tract infections. Reductions in total infection rate and S. aureus infection rate appeared to be less on Wards 4 and 5, which could be influenced by the fact that rates were compared for 6 months pre and post ward closing and cleaning rather than 3 months on Wards 1-3. The impact of a one off environmental intervention is likely to diminish over time. It’s also interesting to note that the MRSA infections identified on Ward 5, a general surgical ward, after cleaning were due to a different strain of MRSA (determined by phage typing and antibiogram) than before cleaning. This new strain matched the outbreak strain from Ward 2. Two of the patients on Ward 5 who became infected with this strain were operated on in the same theatre as the infected patients from Ward 2 within two weeks of one another. Four other patients (on different wards) also appeared to acquire the strain in the same operating theatre.

The study has several important limitations. It is not possible to be certain whether active screening and isolation or ward closing and cleaning were responsible for the reduction in infection rates; it was probably combined impact. The study design lacked the rigor of more modern investigations: infection rates were not expressed in terms of patient-days and infection rates were compared for different time periods making direct comparison of the impact across the five wards difficult. Also, no environmental sampling was conducted to demonstrate the efficacy of the cleaning procedure (both initially and in terms of recontamination).

Notwithstanding these limitations, the study provides evidence that ward closing and cleaning combined with active screening and selective readmission resulted in a dramatic reduction in the rate of nosocomial infection on five study wards. The impact appeared to be most pronounced in the first three months, which is consistent with a reduction in environmental contamination. Outbreaks of MRSA were eradicated by closing and cleaning on all five study wards. However, there was evidence of new nosocomial transmission following the re-admission of infected patients. Finally there was some interesting circumstantial evidence of transmission within operating theatres.

Article citation: Noone P, Griffiths RJ. The effect of sepsis rates of closing and cleaning hospital wards. J Clin Pathol 1971;24:721-725.

How long does it take to clean a hospital room properly?

Jon Otter (@jonotter) Disinfection , ,

Long hours don’t necessarily correlate with productive output. A lifetime’s practice does not necessarily make a champion tennis player. An old boss once told me that “practice doesn’t make perfect; perfect practice makes perfect”. I think there’s something in this that goes some way to explaining the findings of a recent study examining the time taken to clean a hospital room and the thoroughness of cleaning.

You would expect that longer cleaning times would result in more thorough room cleaning. However, the authors used a fluorescent marker to evaluate the thoroughness of cleaning and found no correlation between the length of time cleaning a room and the thoroughness of cleaning.

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Since this was an assessment of “terminal cleaning” (when the patient was discharged) you would hope that the rates of cleaning for the items in the room would be high. However, the marker was removed from less than half marked sites, and only 5% of monitors were cleaned in the 40 rooms assessed. Disappointingly, there was no correlation between completion of a room a cleaning checklist and removal of the markers.

So, the efficacy of cleaning remains low, even at patient discharge, so it is not surprising that admission to a room previously occupied by a patient with certain multidrug-resistant organisms increases the risk of acquisition!

Article citation: Rupp et al. The time spent cleaning a hospital room does not correlate with the thoroughness of cleaning. Infect Control Hosp Epidemiol 2013;34:100-102.