I’ve been struggling for years to find the best ‘catch-all’ term to describe hospital cleaning or disinfection or both. And, after much thought, I’ve settled on a proposal to share with you, dear reader: “environmental hygiene”.
decontamination
Cleaning and disinfection survey
See below details of a survey that you may find interesting to complete. I had a small role in providing some feedback on an earlier version of this survey and I hope it will serve to highlight areas that require more thought and / or research…
On behalf of the International Society of Chemotherapy (ISC) working group on Infection Prevention we would be grateful if you could complete this anonymous survey.
HIS Spring Meeting: ‘Contaminated surfaces: the missing link’
Thought I’d share some key points from the 2016 HIS Spring Meeting.
Outlining the problem(s)
Prof Gary French kicked off the meeting with a (sic) historical perspective, describing how the perceived importance of the environment in transmission has oscillated from important (in the 40s and 40s) to unimportant in the 70s and 80s to important again in the 2000s. Gary cited a report from the American Hospital Association Committee on Infections Within Hospitals from 1974 to prove the point: ‘The occurrence of nosocomial infection has not been related to levels of microbial contamination of air, surfaces and fomites … meaningful standards for permissible levels of such contamination do not exist.’ Gary covered compelling data that contaminated environmental surfaces make an important contribution to the transmission of Gram-positive bacteria and spores, highlighting that C. difficile in particular is a tricky customer, not helped by the fact that many ‘sporicides’ are not sporicidal!
Diluting the efficacy of hydrogen peroxide room decontamination?
A somewhat perplexing new study has just been published in the Journal of Hospital Infection comparing the effectiveness of two hydrogen peroxide based automated room decontamination systems: a low-concentration (5%) hydrogen peroxide system (Deprox) and a high-concentration (30%) hydrogen peroxide system (Bioquell).
The study evaluated the impact of the two systems each run in 10 single rooms containing seeded metal discs placed in five locations, with a 6-log load of MRSA, K. pneumoniae, and C. difficile spores. The MRSA and K. pneumoniae were either low soiling (0.03% BSA) or heavy soiling (10% BSA), and the C. difficile spores was either low soiling (0.03% BSA) or in body fluid. In addition, surface samples were taken from 22 surfaces in each room before and after decon using contact plates. The bottom line is that both systems achieved a >5-log reduction on all of the discs (including those with heavy soiling), and there were no real differences in the levels of surface contamination remaining. All this understandably moved the authors to conclude that ‘The starting concentration and mode of delivery of hydrogen peroxide may not improve the efficacy of decontamination in practice.’
What are we doing to improve hospital room cleaning and disinfection?
I gave a webinar last week for 3M (you can download my slides here) on “Your hospital room can make you sick: How improved cleaning and disinfection can help”. I asked the audience what they were doing to improve cleaning and disinfection, and thought I would share the findings. I don’t know the exact size of the audience (but it’s usually a couple of hundred mainly US based IPC folks), and the audience were allowed to choose any answers that applied to them for the second two questions.
Reflections from Infection Prevention 2015 Part III: Thinking outside the box
For the third and final installment of my blog-report from Infection Prevention 2015, I thought I’d cover some of the more innovative approaches in and around the IPC sphere:
Part II: Improving the systems
Part III: Thinking outside the box
New technology to improve hand and environmental hygiene
I for one am pretty sick of seeing unrealistically high levels of hand hygiene compliance being reported from peer-to-peer manual auditing approaches. One way to get more realistic compliance data is through automated approaches to hand hygiene compliance, reviewed here by Drs Dawson (Warwick) and Mackrill (Imperial College London), who also presented their findings at the conference, and by another group here. Drs Dawson and Mackrill considered issues around product usage, self-reporting, direct observation, perceptions of technology (often viewed, unhelpfully, as a ‘silver bullet’), and staff perceptions of need and benefit. They divided the technology into those that monitored product usage, surveillance systems that monitored individual performance, and systems that monitored both product usage and individual performance. Although automated surveillance systems will always be imperfect and involve a degree of inference, would you rather monitor the 5 moments sporadically / badly or have robust measurements of a smaller number of moments? Automated surveillance methods will not replace manual audits – at least for now – but it’s time to take a long hard look at what is available.
Does chlorhexidine bathing work for Gram-negative bacteria?
The idea of “source control” – using chlorhexidine to reduce the amount of bacteria on a patient’s skin – makes a lot of sense. There’s mounting evidence that chlorhexidine daily bathing works for Gram-positive pathogens, especially in the ICU.1 For example, one of the first thorough studies of chlorhexidine gluconate (CHG) daily bathing showed that the amount of VRE on the skin, in the environment and transmitted to others were all reduced by implementing CHG daily bathing.2 A number of more recent high-quality studies have provided evidence that CHG daily bathing in the ICU setting helps to prevent the transmission of Gram-positive bacteria (see Table below – although note that studies have not been universally positive for CHG).
Table: Studies evaluating the impact of chlorhexidine daily bathing (with or without other interventions) including data on Gram-negative bacteria.
| Study | Setting | Design | Intervention | Results |
| Noto 2015 3 | ICU | Cluster RCT | Daily CHG | No significant reduction in HCAI (composite measure including CLABSI, CAUTI, VAP and CDI) |
| Derde 2014 4 | ICU | Time series analysis | Daily CHG plus hand hygiene | Reduction in all MDROs and MRSA (but not VRE or ESBLs) |
| Seyman 2014 5 | ICU | Before-after | Weekly CHG ‘douche’ | Reduction in BSI but not CLABSI; slight reduction in Gram-negative BSI (n too small for statistical analysis) |
| Hayden 2014 6 | LTAC | Before-after | Bundle (including daily CHG) | Acquisition of CRE fell from 4 to 2 per 100 patient weeks |
| Martínez-Reséndez 2014 7 | ICU | Before-after | Daily CHG plus hand hygiene | Reductions in all infections, and in A. baumannii VAP rate |
| Apisarnthanarak 2014 8 | ICU | Before-after | Bundle (including daily CHG) | Reductions in a. baumannii infection and colonization |
| Climo 2013 9 | ICU | Cluster RCT | Daily CHG | Reductions in MRSA / VRE acquisition and all BSI; BSI mainly CoNS (no significant reduction in Gram-negative BSI or CLABSI) |
| Milstone 2013 10 | Paed ICU | Cluster RCT | Daily CHG | BSI reduced; mainly CoNS (no significant reduction in Gram-negative BSI or CLABSI) |
| Munoz-Price 2010 11 | LTAC | Before-after | Bundle (including daily CHG) | CRE carriage prevalence fell from 21% to 0% |
| Evans 2010 12 | ICU | Before-after | Daily CHG | Rate of CLABSI reduced; A. baumannii colonisation reduced but not significantly |
| Popovich 2009 13 | ICU | Before-after | Daily CHG | Rate of CLABSI reduced; A. baumannii infection rate reduced but not significantly |
| Bleasdale 2007 14 | ICU | Cross-over | Daily CHG | Number of Gram-negative BSI in each arm too small for analysis |
| Gould 2007 15 | ICU | Before-after | Daily CHG + mupirocin | Number of Gram-negatives too small for analysis |
| Camus 2005 16 | ICU | RCT | Daily CHG + mupirocin | Number of Gram-negative acquisitions similar in intervention vs. control groups |
The question of whether CHG is effective for the prevention and control of Gram-negative bacteria is rather more complicated. The main issue is that Gram-negative bacteria are less susceptible to CHG than Gram-positive bacteria.17 In theory, this shouldn’t be a problem because the amount of CHG applied to skin (10,000 mg/L) is much higher than the minimum inhibitory concentration (MIC) of most Gram-negative bacteria.17 However, it’s worth noting that the concentration of CHG measured on the skin of patients being treated with CHG in one study was considerably lower than the amount applied (15-312 mg/L before the daily bath and 78-1250 mg/L after the daily bath).18 Nonetheless, in this same study, CHG was found to be effective in reducing the skin burden of CRE on patients in a long-term acute care hospital (see Figure, below).18 So, should CHG bathing be applied to combat MDR-GNR?
Figure: Impact of chlorhexidine gluconate (CHG) daily bathing on skin colonization with KPC-producing K. pneumoniae in 64 long-term acute care patients (difference is statistically significant, p=0.01).
A number of studies have implemented CHG as part of a bundle of interventions to control various MDR-GNR. For example, a team from Thailand found that an intervention aimed at improving environmental hygiene combined with CHG brought an outbreak of A. baumannii under control.8 The National Institute of Health Clinical Center19 has included CHG bathing as a component of a successful CRE control bundle, and the same goes for long-term acute care hospitals.6,11 Meanwhile, a Dutch study found that implementing CHG bathing combined with improving hand hygiene failed to reduce the acquisition rate of ESBL Enterobacteriaceae.4 A Mexican study implemented CHG bathing combined with improved hand hygiene and reported a significant reduction in VAP due to A. baumannii.7 However, in all of these studies, it is not possible to tell whether it was the CHG or another element of the bundle that made the difference (or not, in the case of the Dutch study).
No study has been designed specifically to evaluate the impact of CHG daily bathing alone on the rate of Gram-negative bacteria infection or colonization, although rate of Gram-negative bacterial infection or colonization has been reported in several studies of CHG. A small number of high-quality studies that have evaluated CHG as a single intervention including randomization have failed to demonstrate a reduction on Gram-negative BSIs and CLABSIs (see the Climo9, Mlistone10 and Camus16 data from the Table above). Also, a non-randomised before-after study in a trauma ICU reported a non-significant reduction in Acinetobacter species colonization.12 Several other studies mention the rate of Gram-negative infection or colonization in passing, but the numbers are too small for meaningful statistical analysis (see Seyman,5 Popovich13, Bleasdale,14 and Gould15). Although these studies do not provide convincing evidence that CHG works for Gram-negative bacteria, it’s important to remember that they were not powered to evaluate the impact of CHG on Gram-negative bacteria.
One final point to consider is the potential for the development of CHG resistance. Units using CHG universally have reported an increase in the presence of bacteria with reduced CHG susceptibility.20-22 However, the actual degree of reduced susceptibility is moderate, meaning that the clinical importance of this reduced susceptibility is debatable. It is true to say, though, that the potential for meaningful reduced susceptibility is greater in Gram-negative bacteria than in Gram-positive bacteria due to their higher baseline MIC and manifold mechanisms of resistance to biocides and antibiotics.17
So, does CHG bathing work for Gram-negative bacteria? Based on current data, we simply don’t know.
References:
- Derde LP, Dautzenberg MJ, Bonten MJ. Chlorhexidine body washing to control antimicrobial-resistant bacteria in intensive care units: a systematic review. Intensive Care Med 2012; 38: 931-939.
- Vernon MO, Hayden MK, Trick WE et al. Chlorhexidine gluconate to cleanse patients in a medical intensive care unit: the effectiveness of source control to reduce the bioburden of vancomycin-resistant enterococci. Arch Intern Med 2006; 166: 306-312.
- Noto MJ, Domenico HJ, Byrne DW et al. Chlorhexidine Bathing and Health Care-Associated Infections: A Randomized Clinical Trial. JAMA 2015 in press.
- Derde LP, Cooper BS, Goossens H et al. Interventions to reduce colonisation and transmission of antimicrobial-resistant bacteria in intensive care units: an interrupted time series study and cluster randomised trial. Lancet Infect Dis 2014; 14: 31-39.
- Seyman D, Oztoprak N, Berk H, Kizilates F, Emek M. Weekly chlorhexidine douche: does it reduce healthcare-associated bloodstream infections? Scand J Infect Dis 2014; 46: 697-703.
- Hayden MK, Lin MY, Lolans K et al. Prevention of Colonization and Infection by Klebsiella pneumoniae Carbapenemase-Producing Enterobacteriaceae in Long Term Acute Care Hospitals. Clin Infect Dis 2014 in press.
- Martinez-Resendez MF, Garza-Gonzalez E, Mendoza-Olazaran S et al. Impact of daily chlorhexidine baths and hand hygiene compliance on nosocomial infection rates in critically ill patients. Am J Infect Control 2014; 42: 713-717.
- Apisarnthanarak A, Pinitchai U, Warachan B, Warren DK, Khawcharoenporn T, Hayden MK. Effectiveness of infection prevention measures featuring advanced source control and environmental cleaning to limit transmission of extremely-drug resistant Acinetobacter baumannii in a Thai intensive care unit: An analysis before and after extensive flooding. Am J Infect Control 2014; 42: 116-121.
- Climo MW, Yokoe DS, Warren DK et al. Effect of daily chlorhexidine bathing on hospital-acquired infection. N Engl J Med 2013; 368: 533-542.
- Milstone AM, Elward A, Song X et al. Daily chlorhexidine bathing to reduce bacteraemia in critically ill children: a multicentre, cluster-randomised, crossover trial. Lancet 2013; 381: 1099-1106.
- Munoz-Price LS, Hayden MK, Lolans K et al. Successful control of an outbreak of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae at a long-term acute care hospital. Infect Control Hosp Epidemiol 2010; 31: 341-347.
- Evans HL, Dellit TH, Chan J, Nathens AB, Maier RV, Cuschieri J. Effect of chlorhexidine whole-body bathing on hospital-acquired infections among trauma patients. Arch Surg 2010; 145: 240-246.
- Popovich KJ, Hota B, Hayes R, Weinstein RA, Hayden MK. Effectiveness of routine patient cleansing with chlorhexidine gluconate for infection prevention in the medical intensive care unit. Infect Control Hosp Epidemiol 2009; 30: 959-963.
- Bleasdale SC, Trick WE, Gonzalez IM, Lyles RD, Hayden MK, Weinstein RA. Effectiveness of chlorhexidine bathing to reduce catheter-associated bloodstream infections in medical intensive care unit patients. Arch Intern Med 2007; 167: 2073-2079.
- Gould IM, MacKenzie FM, MacLennan G, Pacitti D, Watson EJ, Noble DW. Topical antimicrobials in combination with admission screening and barrier precautions to control endemic methicillin-resistant Staphylococcus aureus in an Intensive Care Unit. Int J Antimicrob Agents 2007; 29: 536-543.
- Camus C, Bellissant E, Sebille V et al. Prevention of acquired infections in intubated patients with the combination of two decontamination regimens. Crit Care Med 2005; 33: 307-314.
- Stickler DJ. Susceptibility of antibiotic-resistant Gram-negative bacteria to biocides: a perspective from the study of catheter biofilms. J Appl Microbiol 2002; 92 Suppl: 163S-170S.
- Lin MY, Lolans K, Blom DW et al. The effectiveness of routine daily chlorhexidine gluconate bathing in reducing Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae skin burden among long-term acute care hospital patients. Infect Control Hosp Epidemiol 2014; 35: 440-442.
- Palmore TN, Henderson DK. Managing Transmission of Carbapenem-Resistant Enterobacteriaceae in Healthcare Settings: A View From the Trenches. Clin Infect Dis 2013; 57: 1593-1599.
- Horner C, Mawer D, Wilcox M. Reduced susceptibility to chlorhexidine in staphylococci: is it increasing and does it matter? J Antimicrob Chemother 2012; 67: 2547-2559.
- Otter JA, Patel A, Cliff PR, Halligan EP, Tosas O, Edgeworth JD. Selection for qacA carriage in CC22 but not CC30 MRSA bloodstream infection isolates during a successful institutional infection control programme. J Antimicrob Chemother 2013; 68: 992-999.
- Suwantarat N, Carroll KC, Tekle T et al. High prevalence of reduced chlorhexidine susceptibility in organisms causing central line-associated bloodstream infections. Infect Control Hosp Epidemiol 2014; 35: 1183-1186.
Image: John Loo.
Reflections from HIS 2014, Part II: Dealing with the contaminated environment
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)
Figure: 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!
Ebola: infection prevention and control considerations
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).
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)
As 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…
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.
Reflections on Infection Prevention and Control 