Author: Jon Otter (@jonotter)

SHEA 2013 environment track – conference report

Jon Otter (@jonotter) Conferences ,

When I started doing research in this area a little over 10 years ago, the role of the environment in transmission was rarely mentioned at international conferences. So, to see an entire conference dedicated to discussing the role of the environment in transmission (SHEA 2013, in Atlanta) was a mouthwatering prospect.

SHEA Logo

I’d like to congratulate the organizing committee for putting together such an engaging and entertaining programme. At times, it was true ‘edutainment’.  The slides are available here for delegates.

Stephanie Dancer – plenary

The conference began with a plenary lecture by Dr Stephanie Dancer. Irrepressible as ever, Dr Dancer made a good case for improving hospital cleaning (yes, cleaning using detergent and water – not disinfectants). She highlighted some useful older literature, like this paper from 1963 demonstrating that the role of the environment was considered important once upon a time! She also mentioned a useful initiative that she has been involved with in Scotland, mapping visually where contamination occurs in hospital rooms (amongst other things). Dr Dancer finished by covering some of the newer frontiers in the research area, for example resistance plasmids knocking around in the environment, the role of contaminated air in transmission. I enjoyed Dr Dancer’s presentation very much, although contend that detergent and water cleaning is not always enough, now more so than ever as C. difficile and resistant Gram-negatives continue to cause problems around the globe.

Daniel Morgan – fomites

Next up, Dr Daniel Morgan discussed the role of fomites in transmission. I initially thought that this would overlap with the previous and subsequent presentations, but Dr Morgan stuck carefully to his title and considered the role of individual fomites in transmission. Blood pressure cuffs, stethoscopes (or should we say “staphoscope”!), mobile devices and ties (“neck ties” in American English!) were the subject of his reviews. He performed a literature review on each fomite, identifying a surprising amount of literature. I think that contamination of mobile devices is a large and increasing problem, and regular disinfection should be recommended. Dr Morgan also mentioned the interesting looking ‘hospital microbiome’ study in Chicago. Finally, look out for women’s purses (handbags in English English!) as a potential fomite site!

Tara Palmore – water

Waterborne infections were Dr Palmore’s subject. She began by challenging audience perceptions by claiming that all hospitals have had a waterborne infection in the past 12 months. Dr Palmore described an outbreak of Legionnaires’ disease associated with a fountain in a radiology department. Speaking to staff from another hospital after the talk who have had the exact same problem recently makes me wonder how widespread this problem is! The recent problems with Pseudomonas in ICUs in the UK illustrates the potential ramifications of a contaminated water supply. However, we shouldn’t expect sterile water coming out of the taps. If you need sterile water for a patient, use sterile water!

Rekha Murthy – air

Dr Murthy was considering the role of air in the transmission of nosocomial pathogens. She began with a useful classification scheme for pathogens (inspired by this paper) as “obligate”, “preferential” or “opportunistic” in terms of airborne transmission. We know a lot about “obligate” and “preferential” airborne pathogens like TB and ‘flu. It’s the likely “opportunistic” airborne pathogens that are most interesting to me, such as norovirus, MRSA and C. difficile. Sampling indicates that you can find these pathogens in the air, but is contaminated air a vector, and intermediary between the patient and the surface or an innocent bystander?

Curtis Donskey – impact of environmental interventions

Dr Donskey evaluated the evidence that improving environmental disinfection reduces HAIs. He began by drawing a clever parallel between antimicrobial stewardship and environmental hygiene interventions: you can choose to switch product, educate or automate. Dr Donskey demonstrated ample evidence that switching product, educating and automating environmental disinfection has evidence of reducing HAIs. However, he also discussed the potential problem of publication bias, challenging that we don’t like publishing negative findings due to the perception that we’re “admitting defeat”. Publication bias is a real problem in the scientific literature (see, for example, this study showing publication bias in studies of publication bias!). Another potential problem is that, C. difficile aside, almost all studies include the acquisition of colonization rather than the development of infection due to powering issues. This has implications for the cost-benefit of interventions since infections are where most of the cost of MDROs is accrued.

John Boyce – how to culture the environment

Dr Boyce presented everything that you need to know about culturing the environment. He performed a comprehensive literature review and outlined the options: swabs, sponges, enrichment, contact plates, media and other options. My own preferred method is a swab (which can do regular or irregular objects) that is plated direct (to give a quantitative measure of contamination) and then incubated in broth (to give a qualitative but more sensitive measure). With so much heterogeneity in sampling methods, comparison between studies is almost impossible. More standardization in this area would be useful.

Silvia Munoz-Price – measuring cleaning performance

Dr Munoz-Price considered the options for measuring hospital cleaning, presenting her experience with several UV fluorescent markers and ATP bioluminescence. The experience of Dr Munoz-Price is fascinating, finding that the use of environmental cultures along with fluorescent markers was required to drive compliance with cleaning protocols in their ICU. Markers alone lacked credibility (in the eyes of some ICU staff) and cultures alone were not feasible. Also, Dr Munoz-Price’s experience indicates that one fluorescent marking system was better than another since one was more visible under normal light.

David Weber – new technology

Dr Weber covered recent work on some new disinfectant formulations and “no-touch” automated room disinfection (NTD) systems. He presented some impressive data on improved hydrogen peroxide liquid disinfectants, some of which has been published recently by his group. Then, onto NTD systems. Dr Weber began with some useful criteria for adopting NTD systems: firstly they must be demonstrably safe, secondly they must reduce bioburden, thirdly they must reduce infections and finally they must be cost-beneficial. Dr Weber considered the evidence for the four principle NTD options currently available: hydrogen peroxide vapour (HPV) or hydrogen peroxide aerosol, UVC and pulsed-xenon UV (PX-UV). There’s evidence of safety and bioburden reduction for all systems, and evidence of reduced infections (and/or colonization) for HPV. No cost-effectiveness studies published as yet. So, which NTD system to choose? All systems have their pros and cons, so it will depend on your objectives outlined in this recent review, cited by Dr Weber.

James Steinberg and Craig Zimring – the built environment

Engineering solutions to make the hospital environment more amenable to cleaning and disinfection are an attractive option. With a little planning and thought, new hospitals can be built with infection prevention and control in mind at no (or minimal) additional cost. Also, altering the built environment in existing facilities can yield infection prevention and control benefits. Unfortunately, I missed this lecture, but I suspect the content was similar to their recent review article in the ICHE special edition.

Hilary Humphreys – antimicrobial surfaces

Prof Humphreys gave an accessible overview of the various options to implement antimicrobial surfaces in hospitals. There are various options to consider: metals (principally copper and silver), chemicals or physical changes to surfaces to reduce microbial deposition and/or make them more cleanable. Prof Humphreys mentioned a European testing standard for antimicrobial surfaces that is currently in development and will supersede some (rather wacky) standards that are currently out there. Another problem is that many of the studies supporting the use of antimicrobial surfaces are in engineering journals that seem to speak a different language to the medical literature. Prof Humphreys’ talk helped in interpreting these studies, but more are required in the medical literature. The recently published copper study provides some compelling reasons to prioritize antimicrobial surfaces for further evaluation.

Bill Rutala – disinfectants and microfiber

Dr Rutala presented a convincing case that we should use disinfectants routinely, not just detergents. The main arguments for using disinfectants over detergents for ‘non-critical’ surfaces is that they are more effective at reducing contamination and may have persistent activity, and detergents can become contaminated and spread microbes. It seems that microfiber cloths are better than cotton cloths at removing microbes, but they do harbor them for longer if not disinfected appropriately. So, the evidence for the use of microfiber is somewhat equivocal.

Susan Huang – chlorhexidine bathing

Dr Huang presented three compelling randomized controlled studies evaluating chlorhexidine (CHX) bathing published recently in Lancet, New England Journal of Medicine and one of hers this is not yet published (but doubtless destined for a high-impact journal). The studies seem clear: the introduction of CHX daily patient bathing results in less acquisition, less hand contamination and less environmental contamination. I left the lecture thinking why would you not do this? The potential for reduced susceptibility to CHX is probably the only thing that will stop daily patient bathing using CHX rapidly becoming the standard of care.

Thorny issue #1 – best paths to improve the thoroughness of cleaning (Anne Matlow, Mark Rupp, Larry Nation)

Dr Matlow presented some useful social science exploring the motivations and barriers to compliance with cleaning protocols. Educational deficiencies were identified, for example, almost 40% of housekeepers didn’t think the environment harbored germs that can cause disease. Motivations were explored and it seems that achievement and recognition are more important than pay and advancement.

Dr Rupp presented on the successes and challenges of using audit and feedback to improve compliance with cleaning protocols. Dramatic gains are possible, but it is difficult to sustain the gain. Dr Rupp identified some “positive outliers” during the course of this research. Some would term this group “positive deviants”, but Dr Rupp rightly points out the connotations of this phase are all wrong! There is a potential that these “positive outliers” (if judged by fluorescent markers) are the ones who have clocked the location of the marks and simply spot clean them. Exploring this group in detail will help to confirm that they really are the effective cleaners, and, if so, learn what sets them apart.

Larry Nation is a practicing environmental services director, so was able to provide a complimentary view. His team have moved from visual assessment of cleaning efficacy to a combination of fluorescent marking, ATP and visual assessment to measure the cleaning process and its impact.

All presenters agreed that audit and feedback are essential in setting a path toward improving the thoroughness of cleaning, so Thorny Issue #1 was not all that spiky!

Thorny issue #2 – resistance to disinfectants – Wilcox v Harbarth

Dr Wilcox presented the pro case. Biocide use is gargantuan compared with antibiotic use. However, there is a lot of fear and not much data surrounding biocide resistance. Serial passage of microbes to sub-lethal doses of biocides can induce tolerance, and triclosan is most susceptible to resistance. An area with much equivocal data is the possibility of resistance or reduced susceptibly to skin antiseptics such as CHX. The widespread and most likely increasing use of CHX means that reduced susceptibility would be problematic to say the least. Dr Wilcox presented some compelling data (including some from Dr Harbarth!) that reduced susceptibility to CHX is a problem.

Dr Harbarth presented the con case, although conceded that resistance to skin antiseptics could be a major problem in the future. Dr Harbath argued that antiseptics are a major part of the solution to controlling resistant micro-organisms, not driving the development of the problem! There is very limited evidence of the interaction between antibiotic and biocide resistance and evidence of small reductions in susceptibility that are well below the in-use concentration are not relevant.

On balance, an entertaining debate, and both speakers agree that reduced susceptibility to skin antiseptics is the most likely risk. There is some evidence that small reductions in CHX susceptibility may be relevant even when well below in-use concentrations, and that this may have implications for antibiotic cross-resistance (buried deep in Table 4 of Vali et al. 2008 – look what happened to EMRSA-16 after 48 hours sub-lethal exposure to CHX).

Thorny issue #3 – sporicides for C. difficile – McDonald v Dubberke

Dr McDonald took the pro position, and presented the evidence underpinning the CDC recommendation to use an EPA-registered sporicide for disinfection of rooms potentially contaminated with C. difficile spores. Whilst removal of spores (rather than chemical inactivation) is an important part of the disinfection process, the use of sporicidal disinfectants prevents the dispersal of spores around the room on contaminated cloths. Overall, the evidence for the use of a sporicide to control the spread of C. difficile is overwhelming.

Dr Dubberke presented a rather unenviable con position, given the volume of data supporting the use of a sporicide. However, he did put together a coherent case, highlighting the academic limitations of studies supporting the use of a sporicide, reiterating the risk of publication bias and that practice is more important than product.

Both authors agree that introducing a sporicide will not solve your C. difficile problems; you need to consider all aspects of transmission for that (antimicrobial stewardship, patient susceptibility factors and others). However, the con case presented by Dr Dubberke was not persuasive enough to convince me to abandon the use of a sporicide to help control C. difficile.

Thorny issue #4 – hands v environment – Edmond v Anderson

This debate has been run at several recent conferences so I was concerned that it would be a little “old hat”. How wrong I was.

Dr Boyce (who was chairing) polled the audience at the start of the debate, finding that around 90% thought that hand hygiene is more important than environmental disinfection in preventing HAIs.

Dr Edmond began with the pro. He began by a “thought experiment”, showing that a cluster RCT to compare the impact of the two interventions is not feasible. Dr Edmond acknowledged that there is more and better evidence for environmental interventions than for hand hygiene, but argued that hand hygiene makes a larger contribution to prevention and control. He evaluated the prior room occupancy studies and concluded that the increased risk from the prior occupant only accounts for a small minority of all transmissions.

Dr Anderson’s presentation for the con was outstanding; full of thoughtful, well-constructed arguments. He began with some quotes including the classic “I got 99 problems but the [bleach] ain’t one”; I suspect it was lost on a fair proportion of the audience, but a highlight of the conference for me! Dr Anderson’s argument focused on the fact that there is more and higher quality evidence for environmental interventions than for increased hand hygiene, having scoured the lengthy hand hygiene guidance documents to find a small handful of high-quality studies. In contrast, there are now a number of high-quality studies demonstrating the impact of environmental interventions.

The post-debate vote indicated a swing towards the importance of environmental disinfection, but still the majority concluding that hand hygiene is most important. There can be little doubt that hand hygiene prior to patient contact is the single most important intervention to prevent the spread of hospital pathogens, but it seems that the contribution of the contaminated environment is considerably greater than we thought.

Some points for discussion currently on my mind, mainly prompted by meeting:

  • Should we have a standardized set of environmental sites to sample and a standardized way to sample them to make studies more comparable? (A suggestion by Prof Hilary Humphreys.) I like this idea very much. The only problem is that it may result in widespread “targeting” of these sites only by housekeepers!
  • “The ward is very big; your swab is very small” (Dr Dancer). Are we sampling a large enough surface area? The CDC sponge method will help with this.
  • Can the introduction of single rooms in multi-occupancy bays contain pathogens more effectively (prompted by this image from Dr Weber)?
  • What is the contribution of contaminated air in “opportunistic” airborne pathogens (such as norovirus, MRSA and C. difficile)?
  • How much of a problem is publication bias? Do we really all have negative environment studies that we have not got around to publishing as suggested by Dr Donskey?
  • When are NTD systems warranted, and which NTD system is suitable for the intended application?
  • Should CHX ‘source control’ be implemented universally across the hospital?
  • Are antimicrobial surfaces going to be useful in preventing transmission, and, if so, which is the most effective?

An environmental odyssey

Jon Otter (@jonotter) C. difficile, Disinfection , , ,

Research from the Cleveland VA published in the ICHE special edition tells a fascinating story of sequential interventions to reduce environmental contamination with C. difficile. The research includes pretty much the whole battery of environmental interventions at our disposal: education of housekeepers, the introduction of a specially trained “A” team, ATP bioluminescence, fluorescent markers and UVC for “no-touch” disinfection. About the only thing missing is copper surfaces!

Before we get to the interventions, let’s just reflect on the fact that somewhere between 60-70% of rooms were contaminated with C. difficile after terminal disinfection in the baseline period. It’s little wonder that admission to a room previously occupied by a patient with C. difficile increased the chances of developing C. difficile infection! Related to this, there’s some interesting thoughts at the beginning of the discussion about whether there could be a “safe” level of C. difficile contamination. I discussed this in a previous blog post here.

The introduction of fluorescent marking with feedback did not eliminate the C. difficile environmental contamination, with 50-60% of cultures remaining contaminated. Similarly, the introduction of a UVC “no-touch” room disinfection system for terminal disinfection did not solve the problem, with 30-40% of cultures remaining contaminated. Only when daily disinfection was performed by a dedicated team and terminal disinfection was performed by EVS supervisors and/or the infection control team was the problem finally solved and C. difficile could no longer be cultured from surfaces. It’s disappointing that the intervention that worked in eliminating C. difficile room contamination comprised improvements in both daily and terminal cleaning, so it’s not possible to determine which was most important. It seems likely that a combination of the two did the trick.

environmental-odyssey2

Figure: sequential interventions to tackle environmental contamination with C. difficile.

The study used robust microbiology methods to sample the environment, comprising swabs plated directly onto selective agar, and gauze pads from the same surfaces cultured through broth enrichment. The % positive sites from the enriched gauzes was approximately double the swabs inoculated directly onto agar, demonstrating the value of broth enrichment for environmental sampling.

Another important study finding was that the effectiveness of room cleaning prior to UVC room disinfection was sub-optimal, indicating that the housekeepers were placing too much faith in the automated system, which is designed only to disinfect and not to clean.

So what does this odyssey mean? Firstly that a combination of interventions can be useful, and secondly, the extraordinary lengths required to eliminate C. difficile spores from the environment.

Article citation:

Sitzlar B, Deshpande A, Fertelli D, Kundrapu S, Sethi AK, Donskey CJ. An Environmental Disinfection Odyssey: Evaluation of Sequential Interventions to Improve Disinfection of Clostridium difficile Isolation Rooms. Infect Control Hosp Epidemiol 2013;34:459-465.

How the implementation of hydrogen peroxide vapour (HPV) could save you money

Jon Otter (@jonotter) Disinfection , , , ,

On a recent trip to the US, I asked five or six hospitals what their policy was for dealing with packaged medical supplies (syringes, dressings etc) from the rooms of patients on precautions for MDROs. The response was startling: every hospital had a different policy. The policies ranged from 100% disposal of supplies for every discharge through a “toss heavy toss light” approach depending on the perceived risk of the patient to 0% disposal. I scoured international guidelines and, save a few organism-specific guidance documents, there is no direction on this issue in the guidelines.

What actually happens is another issue. Hospitals with a 100% disposal policy knew that staff often could not bring themselves to throw away perfectly good, sometimes fairly valuable items (IV sets and the like) for the small risk that the packaging may be contaminated. Some threw their supplies into “third world bins” to send to underprivileged hospitals, which is great, unless they happen to be contaminated with an MDRO that would survive the journey! Conversely, hospitals with a 0% disposal policy know that sometimes staff threw out the supplies if the patients had a high perceived risk of shedding. As for the “toss heavy toss light” hospitals: who knows what actually happens.

So, is there a real risk associated with contamination of the packaging of these items? A recent study by Johns Hopkins published in the recent ICHE special issue sampled a selection of supplies to quantify the risk, counted the cost of their current policy and found a potential solution in the use of hydrogen peroxide vapour (HPV) for the disinfection of the supplies. The study found that the packaging of 7-9% of supply items was contaminated with MDROs, and that hydrogen peroxide vapor (HPV) was effective for the disinfection of the supply packaging. The cost of supplies discarded from six ICUs amounted to almost $400,000, not including the costs associated with waste disposal. Hence, the practice of disinfecting the packaging of supplies using HPV would generate substantial cost savings.

Can the introduction of 6 copper items into ICU rooms really reduce the rate of HAI by >50%?

Jon Otter (@jonotter) Disinfection , ,

The recent article by Salgado et al.in the ICHE special edition is the long-awaited copper study: a multi-centre evaluation of the clinical impact of introducing 6 copper alloy high-touch sites into the rooms of patients on three ICUs. I’ve been looking forward to getting my hands on this study for some time!

copper bed

Patients (n=614 following exclusions) were randomized to intervention ‘copper’ rooms and control ‘non-copper’ rooms in three USA ICUs over an 11 month period. The only difference between the rooms was the presence of six items made of copper alloy, comprising bedrails, overbed tables, IV poles and visitor chair arms in all rooms and the nurse call button, computer mouse, computer palm rest and rim of a touch-screen monitor in other rooms.

Patients admitted to copper rooms were significantly less likely to acquire healthcare-associated infection (HAI) or colonization with MRSA / VRE (Figure).

evidence of copper for hai

Figure: difference in acquisition rate between patients admitted to ‘copper’ or ‘non-copper’ rooms

The authors also make an interesting association between the degree of contamination in patient rooms and the risk of acquisition. However, since sampling was performed weekly regardless of a patient’s infection or colonization status, it is not possible to determine whether this association is causal or simply due to the fact that infected / colonized patients are likely to shed more bacteria into the hospital environment.

The study team should be commended for the careful design and attention to detail in the execution of the study. For example, they performed a daily census of the items in the study to determine exactly who was exposed to copper surfaces, and for how long. This indicated that only half of the patients in ‘copper’ rooms were exposed to all six copper items for the duration of their stay, and 13% of patients in the ‘non-copper’ arm were exposed to some copper items during their stay. It’s important to note that the analysis was performed on an ‘intention to treat’ population, i.e. all patients randomized to the two groups, regardless of which items they were actually exposed to. It would have been interesting to see a sub-analysis on the ‘per protocol’ population (i.e. those patients admitted to ‘copper’ rooms and exposed to all six copper items vs. those patients admitted to ‘non-copper’ rooms and exposed to no copper items). Also, I’m not sure why they chose to analysis % acquisition rather than a comparison of rates between the groups. And then there’s the salary support and grant funding to some authors (not directly related to this study) from the Copper Development Association. Notwithstanding these limitations, it does seem that the introduction of copper high-touch surfaces does reduce the transmission of hospital pathogens.

The scale of the difference is incredible. And I mean just that. It lacks credibility. Many will dismiss the study simply because of the scale of the difference between the groups. So, can the introduction of 6 copper items into ICU rooms really reduce the rate of HAI by >50%?

The degree to which contaminated surfaces contribute to the transmission of pathogens is up for debate. I was asked to give a talk at APIC 2012 on the role of the environment. Prior to the talk, I asked the expert faculty a question: ‘What is your estimation of the % of allC. difficile transmission in hospitals that is mediated, directly or indirectly, by contamination of the inanimate environment?’ The answers ranged from 25-75%, reflecting the uncertainty on this issue.

A recently published study by Johns Hopkins provides some illuminating findings (albeit indirectly). Extrapolating unadjusted acquisition rates from all study cohorts indicates that if rooms had been disinfected using hydrogen peroxide vapour (HPV) after every discharge, the overall rate of acquisition of MDROs would have been halved. Whilst it’s not feasible to disinfect all rooms using HPV at patient discharge, this does add some weight to the scale of the reduction identified in this copper study.

It seems that the introduction of a handful of copper alloy high-touch sites had a profound impact on HAI rates. On reflection, I do believe it possible that the scale of reduction in study is “real”. However, questions remain over the practicality and durability of the widespread adoption of copper alloy surfaces in healthcare.

Article citation:

Salgado et al. Copper surfaces reduce the rate of healthcare-acquired infections in the intensive care unit. Infect Control Hosp Epidemiol 2013;34:479-486.

 

ICHE special edition on the role of the environment in transmission

Jon Otter (@jonotter) Conferences , ,

Infection Control and Hospital Epidemiology have dedicated their May issue to articles investigating the role of contaminated surfaces in the transmission of pathogens. There’s an awful lot of good stuff here, but this is my take on the key findings of the studies:

  • Drs Weber and Rutala write a thoughtful introduction covering the highlights of the issue.
  • A study from the University of Maryland shows that admission to a room previously occupied by a patient with ESBL-producing Gram-negative bacteria does not increase the risk of acquisition. This is a surprise because this association has been shown for other pathogens including MRSA, VRE, C. difficile and, most interestingly, other Gram-negatives such as A. baumannii and P. aeruginosa. I suspect this difference is explained by the fact that the Enterobacteriaceae are less able to survive on dry hospitals surfaces than the lactose non-fermenting Gram-negatives such as A. baumannii.
  • Research from the Cleveland VA tells a fascinating story of sequential interventions to reduce environmental contamination with C. difficile. The introduction of fluorescent marking with feedback did not eliminate the C. difficile environmental contamination, with 50-60% of cultures remaining contaminated. Similarly, the introduction of a UVC no-touch room disinfection system for terminal disinfection did not solve the problem, with 30-40% of cultures remaining contaminated. Only when daily disinfection was performed by a dedicated team and terminal disinfection was performed by EVS supervisors and/or the infection control team was the problem finally solved and C. difficile could no longer be cultured from surfaces. This study shows firstly how a combination of interventions can be useful, and secondly, the extraordinary lengths required to eliminate C. difficile spores from the environment.
  • An in situ evaluation of a UVC room disinfection device at Duke / University of North Carolina shows that UVC decreases but does not eliminate key pathogens MRSA, VRE and C. difficilefrom the hospital environment.
  • A study from Johns Hopkins shows that the packaging of 7-9% of supply items was contaminated with MDROs, and that hydrogen peroxide vapor (HPV) is effective for the disinfection of the supply packaging. The cost of supplies discarded from six ICUs amounted to almost $400,000, not including the costs associated with waste disposal. Hence, the practice of disinfecting the packaging of supplies using HPV would generate substantial cost savings.
  • The long-awaited copper study is a multi-centre evaluation of the clinical impact of introducing 6 copper alloy high-touch sites into the rooms of patients on three ICUs. Patients were randomized to intervention copper rooms and control non-copper rooms. Patients admitted to copper rooms were significantly less likely to acquire healthcare-associated infection or colonization with MDROs. The authors also make an interesting association between the degree of contamination in patient rooms and the risk of acquisition. However, since sampling was performed weekly regardless of a patient’s infection or colonization status, it is not possible to determine whether this association is causal or simply due to the fact that infected / colonized patients are likely to shed more bacteria into the hospital environment. The scale of the difference is surprising, with a 50% difference between the groups. I am “a believer” in the role of the environment in transmission, but a 50% reduction attributable to 6 copper alloy surfaces does seem rather high. But it does seem that the introduction of copper surfaces does reduce transmission. Questions remain over the practicality and durability of the widespread adoption of copper alloy surfaces in healthcare.
  • Another University of Maryland study with a powerful cluster randomized controlled trial design shows convincingly that enhanced daily cleaning reduces MRSA and MDR A. baumanniicontamination of the gloves and gowns of healthcare personnel when they exit the rooms of patients on precautions with these pathogens. Now, in theory, healthcare personnel should discard the gowns and effectively disinfect their hands. However, since we know that this doesn’t always happen, these reductions are likely to be meaningful.
  • A study shows that N95 filters to their job and capture infectious influenza aerosols. However, in the event of an influenza pandemic, how long will the stockpile of N95 (FFP3) masks last?
  • An extensive microbiology survey from UCLH in London found that the sites closest to the patient were more likely to be contaminated regardless of ward setting. However, in ICUs, sites touched by staff were more likely to be contaminated whereas in gastrointestinal wards with mobile patients, sites touched by patients were more likely to be contaminated.
  • A short review by Carling and Huang explores evolving issues in how to tackle the contaminated healthcare environment.
  • A novel review piece by a team from Georgia, Maryland and Washington DC provides an overview of how evidence-based design can help to prevent and control the transmission of healthcare-associated pathogens.
  • A study from Florida found that 10% of rooms were contaminated with A. baumannii even when the current occupant was not known to be infected or coloinsed. This could be due to unrecognized infection or colonization, survival from a prior room occupant or important by a the patient, a visitor or healthcare personnel.
  • A study from New Haven, Connecticut found that a new activated hydrogen peroxide containing wipe was highly effective for achieving a hygiene standard of <2.5 cfu / cm2, with 75% of sites yielding no growth at all.
  • A new study from the Cleveland VA shows the value of investing time and resource in observing and supervising cleaning practices in hospitals. Direct supervision of cleaning staff was required to achieve optimal results. The concern is what happens when the direct observation becomes routine or stop all together? Will good practice continue?
  • One of the problems with UV radiation for hospital room disinfection is poor reflectivity from some hospital materials, contributing to reduced efficacy out of direct line of sight and influencing cycle times. An innovative study resulting from a collaboration between healthcare experts at the University of North Carolina and chemical engineers at the University of North Dakota found that using paint that reflects UV more effectively reduces cycle times to achieve comparative efficacy for UV room disinfection.
  • A study from South Carolina provides some further microbiological support for the clinical impact associated with copper surfaces, showing that copper alloy bedrails are associated with significantly lower bioburden than plastic bed rails.
  • A useful study from Ireland tells the story of laboratory optimization of sampling methods, which successfully recovered ESBL producing K. pneumonaiaefrom hospital surfaces.
  • A John Hopkins study provided some promising data of a mobile “UV wand” for the disinfection of hospital surfaces. The device a achieve a 1-log reduction of microbial contamination, and may provide a useful adjunctive approach to hospital disinfection.
  • Some Australian data raised some important questions about the reliability of ATP systems. The relative light unit readings for a dilution series of synthetic ATP were compared against an HPLC gold standard for three ATP systems. Substantial variation was noted for all systems, indicating that RLU values are more indicative than absolute.
  • All but one of the studies in this issue have been in the acute healthcare setting. A study from New York bucks the trend, evaluating S. aureus contamination in maximum security prisons. There did not seem to be an obvious association between S. aureus infection and contamination. If anything, the rates of contamination of inmates and their environment was surprisingly, relative to high rates of colonization with MRSA identified in other studies.
  • Yet more research from the Cleveland VA evaluates a novel disinfectant: an electrochemically activated saline solution, also known as ‘superoxidized water’. Surprisingly, the novel disinfectant performed comparably to 10% bleach for the inactivation of C. difficile in vitro, and eliminated C. difficile contamination from hospital surfaces when applied in situ. This agent should be prioritized for further evaluation.
  • Finally, a French study reports a case of catheter-related bloodstream infection related to a preoperative shower with P. aeruginosa contaminated water. Something to think about next time you have a shower.

The quality and importance of the research in this article has impressed me. However, the fact is that some of the basic questions about the role of the environment in transmission and the most cost effective interventions are yet to be answered. But we’re moving in the right direction.

Evidence that iphones are less contaminated than blackberrys?

Jon Otter (@jonotter) Contamination , ,

iphone

Not so long ago, the use of mobile phones in hospitals was banned for both patients and staff. Nowadays, the use of mobile phones by both patients and staff in hospitals has skyrocketed, and is starting to be embraced with the advent of useful clinical apps. However, as the use of mobile phones in hospitals increases, there is a risk that contaminated phones become a new and difficult-to-manage site for contamination and transmission.

I own a blackberry and my wife owns an iphone. We often talk long into the night about the relative benefits of the phones, and the utility of the blackberry keypad compared with the touchscreen of the iphone is my strongest suit. However, a study from UCL in London provides evidence that the keypad of the blackberry is likely to be more contaminated than the touchscreen of the iphone. Sixty-seven phones were sampled, approximately half of which were touchscreen and the other half were keypad phones. Colony counts were significantly higher on keypad phones, which were also more likely to be contaminated with MRSA or VRE. Overall, 13% of the phones grew either MRSA or VRE, highlighting the potential importance of these sites in transmission.

So why the higher counts from the keypad phones? It seems likely that the nooks and crannies on the keypads allow for the buildup of dust and microbial contamination over time, and make the phones more difficult to clean.

It is unacceptable that 13% of mobile phones are contaminated with multidrug-resistant organisms such as MRSA and VRE. Appropriate disinfection policies are urgently required for these personal, mobile reservoirs of contamination.

Article citation:

Pal et al. Keypad mobile phones are associated with a significant increased risk of microbial contamination compared to touch screen phones. J Infect Prevent 2013;14:65-68.

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.

man_mop

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.

Micro Blog Spring 2013 update

Jon Otter (@jonotter) Updates

Dear Readers,

The micro blog has been going well this year, with weekly updates. These are the featured posts:

It would be good to see some more discussion on the blog, so if you have any questions or comments, please don’t be shy! (There was a problem with blocking some email addresses, but that has now been fixed.)

We’ll continue to update the blog with the latest articles weekly. Look out for twitter updates here, and quarterly emails summarizing the top 5 blogs from the last few months.

If you’d like an email every time the blog is updated, just let us know.

Regards

Jon & Saber.

More single rooms = less acquisition. A simple equation?

Jon Otter (@jonotter) Single rooms , , ,

This isn’t exactly hot off the press (published in 2011) but I’ve only just come across it; it’s a great article and worth revisiting. Many hospitals worldwide suffer a chronic lack of single rooms to place patients requiring contact precautions, but also for patients with other needs such as increased privacy and dignity. There are pros and cons associated with increasing the proportion of single rooms, with a high proportion of single rooms usually requiring a higher staff:patient ratio, and patients in single rooms often having less staff contact and more likely to suffer feelings of isolation. The evidence that an increase in the proportion of single rooms reduces the transmission of healthcare-associated infection has been somewhat equivocal.

This Canadian study evaluated the impact of ‘privatization’ of an ICU. In March 2002, a 24-bed ICU (comprising two 10-bed rooms and four single rooms) was moved to a new 100% single room unit. A 25-bed ICU in a sister hospital (comprising 2, 5, 6 or 8-bed rooms) did not undergo any change in configuration and served as a comparison unit. Importantly, the two units shared the same infection control team, policies and practices. Patients admitted between 2000 and 2005 were studied for the acquisition of a range of pathogens. A unique and useful aspect of the study was to divide microbes into likely endogeneous or exogeneous acquisition. The key result reported was the change in rate ratio of the intervention ICU compared with the comparison ICU before and after the date of privatization of the intervention ICU. This was effectively an estimate of the percentage reduction in the rate in the intervention hospital associated with privatization.

Significant reductions where shown in most pathogens associated with exogenous acquisition, including C. difficile (43%), MRSA (47%) and Acinetobacter spp. (53%), and a substantial but non-significant reduction in Stenotrophomonas maltophilia (52%) (Figure). In addition, a combined analysis of C. difficile, MRSA and VRE also showed a significant reduction of 54%. Significant reductions were also shown for some pathogens in the exogenous/endogenous acquisition group, including Klebsiella spp. (38%). There was no significant change (4%) in the rate of coagulase-negative staphylococci and most other pathogens associated with endogenous acquisition. Perhaps not surprisingly, the authors also reported a reduction in the overall length of stay associated with the intervention.

single room

Figure: Change in the acquisition rate ratio of the intervention vs. comparison ICU before and after before (2001-2002) vs. after (2003-2005) privatisation. (* Not statistically significant.) 

As with all studies, this one is not without criticism. However, there are several aspects that I find particularly convincing. Firstly, whilst there were differences in the configuration of the two ICUs, the inclusion of a comparison unit was an important strength. Secondly, the authors evaluated all available pathogens, rather than focusing on an individual MDRO. Thirdly, and perhaps most convincingly, most pathogens associated with exogeneous infections were affected by the intervention whereas most pathogens associated with endogenous acquisition were not. Additional strengths include several “data-check” sensitivity analyses and an additional model to provide evidence that these were not transient reductions associated with moving to a new, clean unit. Many if not all of these important strengths are lacking from similar studies that have returned a negative result.

The simple equation that more single rooms = less acquisition of pathogens is firmly supported by this study. However, infection rates are not the only factors to be considered when contemplating a move to 100% single rooms. Staffing levels, patients views and up-front costs must be factored into the decision to move towards 100% single rooms.

Article citation:

Teltsch DY, Hanley J, Loo V, Goldberg P, Gursahaney A, Buckeridge DL. Infection acquisition following intensive care unit room privatization. Arch Intern Med 2011;171:32-38.

Carbapenem-Resistant Enterobacteriaceae (CRE) in US hospitals

Jon Otter (@jonotter) CRE , , ,

Enterobacteriaceae are a family of bacteria that commonly cause infections in health-care settings as well as in the community. The family includes more than 70 genera but Escherichia coli, Klebsiella species, and Enterobacter species are the most common in healthcare settings. Until recently, carbapenems have been the treatment of choice for serious infections due to these organisms. However, resistance to these agents has emerged in the Enterobacteriaceae family by various mechanisms and is now a major concern worldwide as infections caused by carbapenem-resistant Enterobacteriaceae (CRE) are difficult to treat and are associated with significant morbidity and mortality.

mmwr

A recent CDC MMWR report used three different surveillance systems to describe the extent of CRE spread among acute-care hospitals in the US as well as the proportion of clinical isolates resistant to carbapenems. They found that while CRE are relatively uncommon, they have spread throughout the US and their rates have increased during the past decade. During the first 6 months of 2012, 4.6% of the 3,918 US acute-care hospitals performing surveillance for either CAUTIs or CLABSIs reported at least once CRE to the National Healthcare Safety Network (NHSN). CRE were more often reported from long-term acute-care hospitals (17.8%) and the percentage of hospitals reporting CRE was highest in the Northeast of the US and among larger and teaching hospitals. Data from NHSN and the Nosocomial Infection Surveillance system (NNIS) showed that the rate of carbapenem resistance among Enterobacteriaceae increased from 1.2% in 2001 to 4.2% in 2011, most of this increase was among Klebsiella species (from 1.6% to 10.4%).

Data from population based surveillance suggest that most (96%) clinical CRE isolates came from cultures collected outside of the hospital from patient with substantial health-care exposure, particularly recent hospitalization (72%). Although nearly all patients with CRE were currently or recently treated in a healthcare setting, these organisms have the potential to spread into the community among healthy individuals.

A combination of infection control strategies applied on national level are needed to control the rise of carbapenem resistance among the Enterobacteriaceae and the spread of CRE. These include active case detection, contact precautions for colonized or infected patients and patient, and staff cohorting as well as strict antibiotic stewardship in all settings. Particular attention should be given to long-term acute-care hospitals which have historically had less developed infection prevention programs. Such coordinated infection prevention and control programs implemented on a national level have been shown to be effective for controlling the rise of CRE, for instance the containment of KPC-producing strains which emerged in 2006 in Israel.

Article citation

Centers for Disease Control and Prevention (CDC): Vital Signs: Carbapenem-Resistant Enterobacteriaceae. MMWR. 2013;62:165-170.