decontamination

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.

Ebola: infection prevention and control considerations

Jon Otter (@jonotter) Ebola , , , ,

I gave a webinar yesterday on some of the infection prevention and control considerations related to Ebola. You can view the recording and download the slides here.

Whilst preparing the webinar, it occurred to me that the real game changer in the outbreak that made the world take note was the three transmissions of Ebola in developed healthcare systems outside of West Africa. One occurred in Madrid, Spain in early October, and a further two occurred in Dallas, Texas, a few weeks later. Before these in-hospital transmissions, there was a general feeling that developed healthcare systems could handle Ebola safely. Clearly, that was not the case!

Furthermore, the ratio of secondary transmissions for dealing with Ebola cases in developed healthcare systems isn’t great: of the 13 cases that have been cared for outside of West Africa, three secondary transmissions have occurred.

The outbreak has thrown up some new challenges, outlined below.

Figure: the emerging challenges of the Ebola outbreak (the dark shaded circles indicate the new and emerging challenges).

Ebola challenges

Many of us now find ourselves scrambling to develop Ebola preparedness protocols. These must start at the hospital door, with carefully considered risk assessments for patients presenting with Ebola-like symptoms. We can’t afford to get our full PPE kits out for every patient who presents with a fever, so what should be the trigger for a suspected case? (PHE and CDC have published useful algorithms to help with this, but it’s not straightforward.)

One area of controversy is the appropriate protocols for terminal decontamination following a case of Ebola. Clearly, the most important risk in terms of transmission is direct contact with blood or body fluids from infected patients. However, despite being an enveloped virus, Ebola can surface on dry surfaces for days to weeks under some conditions in laboratory studies. Furthermore, transmission has been associated with indirect contact with contaminated environments. For example, in a recent report from the field, inadequate use of PPE for dealing with surfaces that were grossly contaminated with body fluids from confirmed cases was identified as one of the risk for acquisition. So, we need to make sure that contaminated surfaces are dealt with appropriately, and most hospitals that have dealt with cases outside of West Africa have used hydrogen peroxide vapour for terminal decontamination.

There is a suggestion today that the epi curve may be peaking in Liberia, which is the epicenter of the outbreak in West Africa. Even if that is the case, we can still expect to see more repatriations to developed healthcare systems and perhaps more cases showing up at our hospitals. So, we need to make sure we do everything in our power to prevent secondary in-hospital transmissions.

My close shave with viral haemorrhagic fever (VHF)

Jon Otter (@jonotter) Ebola, Viruses , , , ,

ebolaAs the outbreak of Ebola continues unabated in Sierra Leone and Liberia (1323 cases and 729 deaths as of July 27), I thought it would be an opportune moment to share a close shave that I had with the closely related Lassa viral haemorrhagic fever (VHF) virus in 2009.

A patient was transferred from Mali to a London hospital with a diagnosis of malaria. The case was initially thought to represent a low risk of VHF (to be fair, Lassa had never been reported in Mali, and the patient came with a diagnosis of malaria). This led to the potential exposure of 123 healthcare workers and visitors, and a busy week for the infection prevention and control team to follow each of these individuals. The useful risk assessment now available from Public Health England may have helped to reduce the number of people exposed.

The patient died in a negative pressure ICU room on the day of admission. At that time, there were no clear recommendations about how to decontaminate the room, so I was involved in developing a decontamination plan with the hospital. Due to the rarity of VHF in the UK, the plan took a week to be authorized by the Health and Safety Executive. This meant that by the time it came to decontaminating the room, the bags of blood-soaked clinical waste, spots of blood on the bed, and used consumables on the floor had been festering for a week. Not ideal.

Our decontamination plan included the use of hydrogen peroxide vapour (HPV) for terminal room disinfection due to the risk that VHF viruses can survive when protected by blood for several weeks on surfaces. This is borne out by some sampling during an outbreak that found intact RNA from the Ebola virus on blood contaminated fomites (although not on fomites that were not contaminated with blood). It’s reassuring that the Department of Health / Health and Safety Executive guidelines published a few years after this case also recommend the use of fumigation for terminal decontamination of hospital rooms.

I ended up being tasked with setting up the HPV equipment that was used to decontaminate the room. We decided it would be better to clean the room after the decontamination to provide some protection to the cleaners. This meant that I was the first person to enter the room after the body of the patient had been removed. I will never forget donning my Tyvek suit, gloves and face-fitted FFP3 mask (see below!). It was exciting: I felt a lot like Dustin Hoffman in Outbreak (the movie that got me interested in medical microbiology in the first place). But it was also frightening. The most frightening part was collecting the bags of clinical waste and consumables from the floor, knowing that they were still likely harbouring live Lassa fever virus. To think that one slip could have infected me with a deadly virus for which there is no treatment…

Lassa PPE me

Figure: Me kitted out in PPE (and looking somewhat apprehensive)

There is legitimate concern that we may see cases of Ebola in the UK and USA in this globalized, interconnected world. If so, then we need to be prepared, and some have questioned our state of readiness. We are fortunate to have comprehensive guidelines from the Department of Health / Health and Safety Executive, including clear guidance on how to decontaminate a room following a case of VHF.

My close shave with VHF has given me a great deal of respect and, frankly, veneration for the brave healthcare workers who are risking their lives on the front line in bringing the current outbreak of Ebola under control.

Photo: Ebola courtesy of Phil Moyer and CDC/Cynthia Goldsmith.

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.