HIS Poster Round: Dealing with contaminated hands, surfaces, water and medical devices

poster round

I was delighted to be asked to lead a poster round at the Healthcare Infection Society (HIS) conference. I was a bit disappointed to see that the poster sessions are tacked on to the end of the day (when everybody’s had enough and really just wants to retreat to their hotel room for an hour before the evening’s activities). My view is that posters are the lifeblood of conferences (and I am not alone in this view); they should have much more prominence, with a “ringfenced” session integrated into the main program.

Anyway, whinge over, I thought I’d share which posters I chose, why I chose them, and what I want to know about them.

You can access the abstracts here.


#3200 Longhurst et al. Hand drying methods in NHS England Trusts, September 2013.

I chose this poster because it’s becoming increasingly clear that the choice of hand drying method can influence the degree of bacterial contamination. Also, whilst I accept the economic and environmental benefits of jet and warm air dryers, they always seem to leave my hands a bit damp. (Perhaps I just have sweaty palms.) Anyway, this is what I want to know about this poster:

  • Why did you feel the need to ‘enforce’ a response by using the Freedom of Information act?
  • Why do you think jet / warm air dryers were rare in clinical areas?
  • Do you think that jet and to a lesser extent warm air dryers result in dangerous dispersal of microbes?

#3349 Tang et al. A 3 year hand hygiene program to increase compliance rate for heatlhcare providers in the A&E Department of Tuen Mun Hospital in Hong Kong.

There’s not a lot of data on hand hygiene compliance in A&E. A 2005 study examined compliance with hand-washing in the TV show ER, reporting a hand hygiene compliance rate of 0.2%. Yep, that’s ZERO POINT TWO PERCENT! Although reality is marginally better (according to this review), there’s work to be done, so I chose this poster mainly because of the impressive impact in improving hand hygiene compliance. My questions are:

  • Which of the barriers to hand hygiene that you mention do you think is most important?
  • Who was on your task-force to decide what to do?
  • How many people completed the questionnaires?
  • How many observations were done in each time period?
  • How do you measure that the awareness of hand hygiene increased?

#3174 Khanafer et al. Hospital management of Clostridium difficile infection: a literature synthesis

This is a novel review of the literature: using the ORION checklist to capture variables that help us to determine what works to control CDI from outbreak reports and intervention studies. Here’s what I want to know:

  • Can we really derive anything useful about which intervention works when you have more than one variable, even if studies are reported in a structured way? (High school science is pretty clear: change one variable at a time!)
  • How can these % reductions be so high when (apparently) only 30% of CDI is hospital-acquired (according to some people’s interpretation of the Oxford WGS difficile study)?
  • Which is the single most important intervention to prevent CDI transmission?


#3285 Cunningham et al. VRE Outbreak Control – the Need for Speed (Use of Molecular Technology)

Two of my favourite subjects: VRE and rapid diagnostics! Here are my questions:

  • Why bother trying to control VRE? Some pretty persuasive voices are arging that it’s not worth it!
  • Are you sure that rapid diagnostics made the difference? You also introduced enhanced cleaning / disinfection, extra screening, pre-emptive isolation, and extra staff and equipment.
  • How do you explain the four clusters?
  • Did you culture in parallel? If so, what was the sensitivity and specifity of the PCR test?

#3312 Whiteley et al. The problem of rapid ATP systems may be scaling using Relative Light Units (RLU)

This poster wins the prize for the most detailed poster in conference history; I think they’ve squeezed enough words in for a full length article. But the findings are important. All ATP bioluminescence systems are not equal: a way to standardize RELATIVE light unit (RLU) output would be extremely useful.

  • What is ‘coeffecient of variance (CoV)’, and what does it mean?
  • Does lower CoV = a better ATP bioluminescence system?
  • Clearly, hand held luminometers will not match HPLC in terms of accuracy, but what should our ‘CoV’ tolerance be?
  • Do you have a way to distinguish variaibilty of sampling (i.e. pickup of ATP on the swab) from variability in ATP detection by the device?
  • Would ATP correlate better with microbial concentration if device variability were removed (e.g. through HPLC analysis)?

#3393 Maynard et al. The use of Pseudalert® for the routine analysis of water samples by engineers

I like technology and I like innovation, so this is right up my steet. Here’s my questions:

  • How does the limit of detection for Pseudalert (1 cfu / 100 mL) compare with conventional culture, in theory?
  • How much training is required to use it?
  • Why 100 mL for Pseudalert, and 500 mL for culture?
  • Is culture the gold standard method? If so, the specificity of Pseudalert in Hospital 1 is terrible!


#3197 Farrugia et al. Reducing methicillin resistant Staphylococcus aureus (MRSA) bacteraemia in haemodialysis patients within a high incidence setting

I chose this poster purely for the dramatic reduction in MRSA bacteraemia in a specialist setting. I would like to know:

  • Is the high initial rate explained by haemodyalisis cathethers being left in for too long?
  • ‘Prevalence of CA-MRSA 8.8%’? What does this mean? 8.8% of healthy individuals carrying CA-MRSA, or 8.8% of hospital MRSA is community-associated clones?
  • Lots of interventions – do you have a feel for which was most important?

#3277 Stenger et al. A hydrogel interpenetrating polymer network in vascular catheters loaded with thioridazine and dicloxacillin facilitates slow surface release and inhibits staphylococcal biofilm formation in vitro and in vivo

I am interested in approaches that replace the traditional use of antibiotics with biocides (which have a much lower risk of promoting bacterial resistance). Whilst this catheter was dosed with an antibiotic, I think the technology could theoretically be dosed with any biocide. Also, I’m fascinated by the application of an anti-psychotic drug in infection control:

  • Please explain the principle of ‘interpenetrating polymer network’ (IPN).
  • Could this same technology be used to dose the catheters with any drug or biocide?
  • Can you modify the rate of release?
  • Who on earth decided to see whether an anti-psychotic drug (thioridazine) has antibacterial properties?

If anybody has any answers to my questions, please fire away!

Image: Andrea Wiggins.

11 thoughts on “HIS Poster Round: Dealing with contaminated hands, surfaces, water and medical devices

  1. Thanks Jon for choosing our poster. The high MRSA bacteraemia rate was attributed to the fact that these were non tunnelled haemodialysis catheters left in situ for several weeks and even months. When a problem with blood flow was encountered, nurses used to manipulate the haemodialysis line, pulling & pushing, until blood flow improved. This manipulation is not possible with tunnelled lines.

    8.8% of healthy Maltese population are colonised with MRSA. Published study by Scerri et al (2013) Prevalence and characteristics of community carriage of MRSA in Malta in JEGH.

    We cannot identify which factor was most important. There were several processes which needed to improve and this was achieved during the last 3.5 years.


    • The idea of a nurse giving the line a good yank to get the blood flowing gives me one of those unpleasant shivers! Congrats again on such impressive reductions.


  2. Thank you Jon for having chosen our poster. I am really flattered that you considered it as novel!
    You are right about the difficulty to attribute effect to an intervention when we conducted a multifaceted interventions. The problem is what variable having priority: antibiotics? hand hygiene? disinfection? … the importance of these variables can vary between hospitals, countries…
    A unique intervention may be more effective in one ward or one hospital than a multi-component interventions because at baseline problem was different.
    In published papers, when we talk about rate of CDI people dont stratified all time this rate according to the origin of acquisition. Personally, I think that good percentage of CDI cases were misclassified.
    Finally to prevent transmission the key element is ENVIRONNEMENT DISINFECTION (+hand hygiene). Antibiotic stewardship is important but isn’t enough especially as professional practices and infectious diseases epidemiology’s are highly variable.


    • Thanks for the further information Nagham. I completely agree that the relative impact of various interventions will vary by context (e.g. organism, setting).


  3. Thanks for keeping us up to date on all infection control aspects.
    Is it possible to get you email address since a need an advice on publishing a paper?

    Best Regards


  4. Hi Jon, many thanks for choosing our poster. We were delighted that we we got to present to a wider audience! Please see below replies to your questions:
    •Why did you feel the need to ‘enforce’ a response by using the Freedom of Information act?
    We wanted to understand how deeply electric air dryers have penetrated healthcare as it is an environment where risk of cross contamination is so high. And there has been evidence to suggest that paper towels are a more hygienic method to dry hands. We felt that requesting this info under FOI Act will give us a clearer picture of the situation.

    •Why do you think jet / warm air dryers were rare in clinical areas?
    We like think to that many infection control nurses have concerns about the use of electric driers in clinical areas and believe that the use of single use towels is the most hygienic option. Historically paper hand towels have been considered to be the most hygienic way to dry the hands, but the new high speed hand driers are being positioned as being ‘high- tech’ and more effective than paper hand towels. Fortunately, we suspect that cost may also play a role and that Trusts do not want to pay for electrical driers. We are aware that the manufacturers of electrical driers are promoting the ‘hygienic’ and environmental credentials of high speed driers and often talk to facility managers rather than infection control personnel. Facility managers may purchase driers based on criteria other than hygiene

    •Do you think that jet and to a lesser extent warm air dryers result in dangerous dispersal of microbes?
    If pathogens still present on the hands after washing, then yes the use of electrical driers are likely to aerosolize the microorganisms in the water droplets on the hands and disperse them 2-3 metres away from the driers. In addition, the microorganisms can remain in the air for 15 minutes or longer. Therefore, the use of electrical driers in the public areas of hospitals could disperse Noro virus for example, from the hands of an infected person into air and then contaminate the users and bystanders in the washroom. This may occur for more than 15 minutes after the infected person left the washroom. Visitors using these washrooms may then transfer the Noro virus to the wards when visiting friends and relatives. It is well known that the NHS is struggling to control the spread of Noro virus in its hospitals.
    Hope that answers your questions.
    Thanks again for shortlisting us.
    Kind regards,


    • Thanks Marta – somewhat frightening that norovirus could be aerosolised during the hand drying process. Yet another reason not to visit a hospital in the winter!


  5. Dear Jon Otter,
    Once again, thank you for choosing our poster for the poster walk presentation. We will be happy to answer your question.

    • Please explain the principle of ‘interpenetrating polymer network’ (IPN):
    The tunability of the physical properties of CO2 combined with the unique nature of silicone elastomer result in a thermodynamic favourable situation where it is possible to tailor the properties of the silicone rubber by impregnation of different substances such as hydrophilic monomers. Hydrophilic monomers is polymerized and cross-linked resulting in a hybrid material with an interpenetrating polymer network (IPN) as illustrated in figure 2 on our poster.
    To put it another way: Silicone rubber is exposed to supercritical CO2 which makes it swell like a sponge. This enables introduction of monomers which can be polymerized inside the silicone material to a hydrogel (polymer network). When removed from the supercritical CO2, a “hybrid” material is formed in which active substances can be loaded for subsequent slow release, e.g. when placed in a blood vessel.

    • Could this same technology be used to dose the catheters with any drug or biocide?
    Yes, It may be loaded with any other molecules, although our data suggest that larger molecules such as proteins (above 20-30 kDa) are difficult to load probably due steric hindrance

    • Can you modify the rate of release?
    Yes, we can change the rate and the duration of release by tuning the hydrogel-silicone ratio and using different hydrogels. However, we are still working to understand how release kinetics are affected by these properties.

    • Who on earth decided to see whether an anti-psychotic drug (thioridazine) has
    antibacterial properties?
    Actually the antimicrobial properties of anti-psychotic drugs (especially phenothiazines) has been known for over a century – first discovered by Ehrlich in 1891 (methylene blue) and was almost forgotten due to the “golden age” of antibiotics. But in the late seventies the extraordinary antimicrobial effects of these drugs were rediscovered due to increasing antimicrobial resistance and moreover, the possibility of using thioridazine in combination with a beta-lactam antibiotic has since proven very effective against MRSA in vitro. Furthermore, resent studies have shown that the combination treatment also has an enhanced effect against MSSA and biofilm formation. Unfortunately, thioridazine was withdrawn from the market in 2005 due to cardiotoxic side effects, which for now makes systemic treatment in the clinical setting controversial.


    • Thanks for the information Michael. Could you use the same technology to make hard surfaces antimicrobial e.g. hospital bed-rails?


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