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Glenys
Perhaps “routine” was a bad choice of words. What I am talking about is a standardised, more sensitive sampling technique. I dont think that anyone would argue that four or five swabs of 1cm2 gives an accurate representation of the level of biological contamination within a patient room or bed space.
Without am accurate picture it’s impossible to tell how successful any intervention has been. If you look at the various studies that do look at the level of environmental contamination there are hugely different findings as to the level of contamination before and after interventions. I have a hard time believing that such a variation is totally down to the cleaning techniques employed in the different hospitals especially when you look closely and realise that the studies reporting the higher level of contamination tend to use either more sensitive sampling techniques or perform high number of surface swabs.
Regarding “is the environment supposed to be sterile”. I think thats the debate we are having.
Firstly, I am talking about discharge cleaning and disinfection when a patient has vacated the room. Daily cleaning and disinfection is a separate issue. The standard should be different for various room categories. For example, a room vacated by a patient with Cdiff will require more attention than a room vacated by a patient who was not known to carry a pathogen. While “sterile” may be an unobtainable goal we should certainly be aiming for pathogen free. All the data show that even low levels of environmental contamination in a room increase the risk of acquisition to the next patient being admitted to that room. I would argue that if our aim is to reduce acquisition rates, and minimise risk to patients then “pathogen-free” is what we should be aiming for.
The level of environmental contamination that creates a risk is unknown but what we do know is that the risk of transmission is directly proportional to the level of contamination in the environment (Lawley et al. 2010 and Datta et al. 2011). Lawley also demonstrated that for C.diff that 1cfu cm2 of environmental contamination was sufficient to cause infection in mice. We also know that the infectious dose for some pathogens is extremely low, For noro virus 1 to 10 virus particles are sufficient to cause infection (Yezli and Otter 2011).
At the very least I think we should set a target, a maximum level of bio contamination, within a room that is acceptable (in 2004 Dancer proposed a level of < 1cfucm2) and then we need to find a way or technique that can achieve this goal, repeatedly and reliably.
I also suspect that this target will be location specific. What I mean is high risk locations such ICU, Organ transplant or Oncology will have lower maximum levels (perhaps <1cfu per cm2 as suggested by Dancer) than "lower risk" areas such as a general medical ward.
The alternative is to set a "target" decontamination challenge, say a 6 log sporicidal reduction similar to the that already implemented in for autoclaves.
I would argue that any of the data I have seen (see papers referenced in my previous reply) would suggest that traditional "cleaning" techniques cannot achieve this goal. I think that Farrin Manian's research goes the furthest to show that even enhanced environmental cleaning cannot eliminate environmental contamination and that going that extra step does have a significant impact on acquisition rates, even in an non outbreak situation. Passaretti's data demonstrate that eliminating environmental contamination significantly reduced the risk of acquisition to the patient being admitted to the room, again in a non outbreak situation.
Even if we accept this and agree that one of the new technologies are required to achieve this new standard that does not negate the need for cleaning. These technologies will only be used on a subset of rooms vacated by patients with pathogens. Also, any of the technologies you mention are adversely affected by the presence of organic matter. It goes right back to what we learnt over 100 years ago, first you clean then you disinfect.
That is why I think this debate is so important. If we accept that elimination of environmental pathogens is the goal then it will require a fundamental change in how environmental decontamination, or cleaning, is viewed and require a complete rethink of how we implement and monitor the environment in Hospitals. For that to happen then debates such as this are a vital part of achieving the consensus required.
Regards
Kevin Griffin
Director Healthcare Solutions
Bioquell Asia Pacific Pte Ltd
T: +65 6592 5145
F: +65 6227 5878
M: +65 8511 3733
E: Kevin.Griffin@bioquell.com
W: http://www.bioquell.com
—–Original Message—–
From: AICA Infexion Connexion [mailto:AICALIST@AICALIST.ORG.AU] On Behalf Of Glenys Harrington
Sent: 16 September 2011 20:30
To: AICALIST@AICALIST.ORG.AU
Subject: Re: Environmental hygiene and disinfection as part of Standard Precautions model
Kevin,
Perhaps the answer is not to look for a "defined routine sampling technique to determine a minimum standard for environmental contamination" as there will always be problems with interpreting what the results mean given the environment is not meant to be "sterile".
It would be more useful to determine what are the minimum, standardised, "reliable and repeatable" environmental decontamination procedure/s (i.e. cleaning and the use of florescent markers/cleaning and the use of microfiber/cleaning and chemical disinfection/cleaning and new technologies [HPV, UV, steam, other]) that can be shown to be linked to a sustainable reduction in infection and/or colonisation in patients in non-outbreak settings.
Regards
Glenys
Glenys Harrington
Consultant
Infection Control Consultancy (ICC)
PO Box 5202
Middle Park
Victoria, 3206
Australia
H: +61 3 96902216
M: +61 404 816 434
infexion@ozemail.com.au
ABN 47533508426
—–Original Message—–
From: AICA Infexion Connexion [mailto:AICALIST@AICALIST.ORG.AU] On Behalf Of Michael Wishart
Sent: Friday, 16 September 2011 7:12 PM
To: AICALIST@AICALIST.ORG.AU
Subject: Re: [AICA_Infexion_Connexion] Environmental hygiene and disinfection as part of Standard Precautions model
[Moderator note: this message has been discussed with the original poster of this thread, and agreed that the content is not product specific and is worth consideration as part of this discussion.]
John
I read your post with great interest and think its a fantastic topic (and badly needed) for discussion.
I was going to reply to the list but to be honest I am coming from a slightly biased perspective and really do not want to the list to degenerate into another marketing tool (or for that matter to get into trouble with the people who manage the list.) so here is my (for what its worth) feelings on the topic. Any feedback appreciated and if you feel its not going to be taken or seen incorrectly then I am happy to reply to everyone.
Unfortunately while opinion is changing (and changing rather quickly) there is still debate in some circles as to the role of the environment in the spread of HCAIs. History tells us that the medical profession takes a while to change its mind (look at Semmelweis or John Snow)!
The historical belief that pathogens dont survive long in the hospital environment has been proven to be completely wrong with evidence that the many bacteria can survive weeks, months or even years in the environment. The feeling that the patient contaminated the environment but that the a contaminated environment was not a risk to a patient has been reassessed and found to be incorrect in some circumstances. The question is not now whether a contaminated environment makes an important contribution to transmission but how much of a contribution does it make. Related to this, what level of cleaning and disinfection is required? Is cleaning enough? Do we need disinfection? To what level?
What is exacerbating the problem is the lack of data on the actual level of contamination that exists in hospitals pre and post cleaning. Taking two or three swabs, even on a routine basis just isnt sensitive enough to give us that kind of data. How can sampling 2cm2 out of the entire surface area (even out of the high hand touch surfaces) even give us an indicative result on the level of contamination in a room? There is even some doubt as to the sensitivity of standard swabbing. If you look at a letter in AJIC in 2009, (Otter JA et al. Am J Infect Control
2009;37:517-8) standard swabbing found 2% of surfaces contaminated with C.diff but moving to the newer pre moistened cellulose sponges swabbing
1m2 found that 28% of surfaces were contaminated. This goes to show how inaccurate or lacking sensitivity our environmental testing, even when it done routinely.
We all know that the environment contaminates healthcare workers hands, particularly the near patient environment. There are multiple studies that show this but the one that to me stands out is Hayden et al. Infect Control Hosp Epidemiol 2008;29:149-154 which showed that VRE touching that surface was posed the same risk of contaminating a HCW hands as touching the patient !!!
The most convincing evidence that contaminated surfaces are important in transmission comes from the fact that there is an increased risk to a patient of acquiring a MDRO if the previous patient in that room had a MDRO:
Martinez et al. Arch Intern Med 2003; 163: 1905-12 showed if VRE was cultured within the room the risk to the next patient increased by a factor of 2.6, Huang et al. Arch Intern Med 2006; 166: 1945-51 showed that if the prior room occupant had VRE the risk increased by a factor of 1.6 and for MRSA it was 1.3 Drees et al. Clin Infect Dis 2008; 46:
678-85. demonstrated that if VRE was cultured within the room that the risk increased by a factor of 1.9. prior room occupancy risk increased by a factor of 2.2 and more worryingly even with all the cleaning that if the previous room occupant at any tome in the previous 2 weeks had VRE the risk still increased by a factor of 2.
Shaughnessy. Infect Control Hosp Epidemiol 2011;32:201-206 showed that if the prior room occupant had C.diff that the risk to the next patient admitted increased by a factor of 2.4.
Nseir et al. Clin Microbiol Infect 2010 looked at the MDR Gram Negatives and showed that prior room occupancy was also a significant risk factor.
For Acinetobacter you risk increased by a factor of 3.8 and for Pseudomonas the risk factor increased by 2.1.
So, having established that the environment contributes to transmission, the question is, what is the best way to reduce the contamination to a safe level?
We also know that cleaning and disinfection, even with the best technique will not reliably eradicate this environmental contamination.
As far back as 2004 Garry French French et al. J Hosp Infect
2004;57:31-37 showed that manual cleaning failed to eradicate environmental contamination from MRSA. Byers et al. Infect Control Hosp Epidemiol 1998;19:261-264 showed that it took an average of 2.8 disinfections to eradicate VRE from a room, Boyce et al. Infect Control Hosp 2008;29:723-729 showed that bleach leaning failed to eradicate C.diff (using the more sensitive Sponge testing 25% of surfaces remained contaminated after bleach cleaning).
Similarly, Farrin Manian demonstrated at SHEA in 2010 (and since part published Manian et al. Infect Control Hosp Epidemiol
2011;32(7):667-672) that even with 2 daily bleach cleans and 4 repeat bleach cleans on patient discharge that 26.6% of rooms remained contaminated by MDR Acinetobacter or MRSA !!!!! 4 repeat bleach cleans
How many hospitals currently or will ever go to that standard ??
In the same study as above, Farrin Manian showed that Hydrogen Peroxide Vapour (HPV) was more effective than the four rounds of cleaning and bleach disinfection. Furthermore he demonstrated (again in SHEA 2010 but not yet published) that by eradicating this contamination (using Hydrogen Peroxide Vapour) that there was a 54% reduction of patient acquisition rates for MDR Acinetobacter, 42% reduction on C.diff, 50% reduction in VRE and a 24% reduction in MRSA !!
Two other studies also suggest that eradicating environmental contamination reduces the acquisition of pathogens. John Boyce showed at SHEA in 2006 and since published, Boyce et al. Infect Control Hosp
2008;29:723-729 that eradicating C.diff from the environment (again using HPV) reduced patient acquisition rates for C. diff by 54%. In another study of HPV decontamination in 2008, Passaretti presented data at SHEA (still to be published and again using HPV) demonstrating that by eradicating environmental contamination from a room where the previous room occupant had a MDRO that the risk of acquisition to the next patient dropped substantially. From VRE there was a 77% reduction, for MRSA a 54% reduction for C.diff a 65% reduction and for Gram negative rods a 38% reduction. Over all the eradication of environmental contamination on patient discharge reduced the risk of acquiring a MDRO by 66%…..
So, yes, routine cleaning and disinfection of the rooms of patients on MRO precautions should be done but more may need to be done a patient discharge to eradicate pathogens for the safety of the next patient.
Regarding terminology, I tend to use environmental decontamination to encompass both cleaning and disinfection, but standardisation would be helpful here.
I think we need to define a routine sampling technique and a minimum standard for environmental contamination that must be achieved before a patient can be admitted to a room or bed-space. (I suspect different standards can be set for different areas depending on risk, for example in Oncology, ICU and Organ transplant the standard may be <1 CFU per CM2 for general medical ward it could be <2CFU per cm2.) There are some proposed guidelines (J Hosp Infect 2004; 56: 10-15 but these have not been adopted widely). We need to find a reliable and repeatable method of achieving this standard and it needs to be implemented and monitored.
And there needs to be a budget made available for this.
Regards
Kevin Griffin
Director Healthcare Solutions
Bioquell Asia Pacific Pte Ltd
T: +65 6592 5145
F: +65 6227 5878
M: +65 8511 3733
E: Kevin.Griffin@bioquell.com
W: http://www.bioquell.com
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