Preventing healthcare-associated COVID-19

The issue of preventing healthcare-associated COVID-19 is very topical right now, to say the least (see this JAMA commentary), so now is a really good time to review what happened in our hospitals during the ‘first wave’ to help us prevent hospital transmission during the second.

The study was performed during the first wave of COVID-19 in London, between March and mid-April. The focus of the study was on ‘hospital-onset definite healthcare-associated’ (HODHA) COVID-19 infections (with a sample date >14 days from the day of admission). Overall, 58 (7.1%) of 775 symptomatic COVID-19 infections in hospitalised patients were HODHA. Key findings included:

  • Compared with community-associated COVID-19, patients with HODHA were more likely to be older, Black Asian or Minority Ethnicity (BAME), have several clinical underlying conditions (e.g. malignancy), and had an increased length of stay after COVID-19 diagnosis. Surprisingly, there was no increased risk of mortality (either 7, 14, or 30-day) or ICU admission.
  • There was an interesting analysis of the impact of a delayed positive test (where there was no positive test within 48 hours of symptom development). This occurred in about a third of HODHA cases, and was associated with an increased risk of 30-day mortality.
  • A potential source patient (a positive case on the same ward within 14 days of the positive test) was identified for 44/58 HODHA cases.
  • There was a correlation between weekly self-reported sickness absence incidence and weekly HODHA incidence.

This is a similar piece of work to our analysis of healthcare-associated COVID-19. The period of time covered was almost identical (from March to mid-April) and the number of HODHAs was very similar (62 in our study compared with 58 in this study). This seems to illustrate how indiscriminate this outbreak has been regionally – a wave of healthcare-associated COVID-19 swept through our hospitals in March/April – and our job now is to reduce the size of this wave over the winter!

Can we halve GNBSI? The crowd say no…!

I participated in another pro-con debate recently up against fellow Reflections blogger Martin Kiernan during a Webber Teleclass. The question for the debate was “Can we halve Gram-negative BSI?” (I was arguing that we can). We ran a live Twitter poll and the outcome: 59% of the 22 respondents voted that no, we can’t halve GNBSI.

The slides from my talk are here.

My argument had two main themes: that there is a sizeable preventable portion of GNBSI and we have a lot to go for, and that we need a new approach to preventing GNBSI that will require new models of collaborative working across acute and non-acute health and social case.

The image below maps out the drivers of GNBSI. Some of these are modifiable (e.g. hydration and UTI, devices, antimicrobial stewardship), and some are not (e.g. deprivation [ok technically modifiable but beyond the scope of most IPC teams!], seasonal variation). The aim here is to identify those drivers of GNBSI that are modifiable and come up with practical interventions that could make a big difference.

Figure: Drivers of Gram-negative BSI.

Hydration is a good example. The most common source of E. coli BSI (which accounts for most GNBSI) is UTIs. We know that poor hydration is an important risk factor for UTI. So if we can improve hydration – in hospitals and outside – then there’s a good chance we’ll reduce UTI and in doing so reduce E. coli BSI.   

Antimicrobial stewardship is another. If we can improve the management of Gram-negative infections in the community through appropriate therapy outside of hospital admissions, then you reduce the chance that they’ll progress to a GNBSI.

I can’t tell you for sure that we can halve GNBSI. But we must try to prevent the preventable GNBSIs!

Should we routinely audit hand hygiene in hospitals? The crowd say no…!

I had the privilege of participating in the IPS Autumn Webinar series yesterday, in a debate with Dr Evonne Curran on whether we should routinely audit hand hygiene in hospitals. It was good fun – and highlighted some important points about the strengths and limitations of hand hygiene audits – and audits generally for that matter!

Here’s my case for routine hand hygiene auditing in hospitals (you can register (free!) and view the webinars here):

My key arguments were that:

  • Hand hygiene is really important, and one of a range of interventions that we should be routinely auditing to launch focussed improvement work.
  • There are key sources of bias in hand hygiene auditing (see below). However, these can be reduced with optimised methodology.
    • Observation bias (aka Hawthorne effect) – where behaviour is modified by awareness of being observed. For example, if I stand over you with a clipboard and a pen, you’re more likely to do hand hygiene.
    • Observer bias – difference between the true value and the observed value related to observer variation. For example, poor trained auditors will result in variations in reported practice due to observer bias.
    • Selection bias – when the selected group / data does not represent the population. For example, only doing hand hygiene audits during day shifts won’t tell you the whole picture.
  • Hand hygiene audits are a legal and regulatory requirement (in England at least).
  • My own experience is that optimised hand hygiene auditing methodology can deliver a performance indicator that can identify areas of poor performance and drive focussed improvement initiatives.

At the end of the debate, two thirds of the live audience voted against doing routine hand hygiene audits in hospitals. Put another way – I lost! I am taking the view that the audience voted against the concept of inaccurate auditing returning unrealistically high level of compliance, rather than against properly monitored and measured auditing, which can help to fuel improvement.

If nothing else, I hope the debate made the point that poorly planned and executed hand hygiene auditing is doing nobody any good – and may be doing harm. If we are going to do hand hygiene auditing, it should be using optimised methodology to deliver actionable information that is put to work to improve hand hygiene practice.

Face coverings, surgical masks, and face filtering piece (FFP) respirators: what’s the difference and how are they tested?

You’ll all have seen wide variety of masks and face coverings worn in a wide (and often alarming!) variety of ways. Leaving aside the (in)correct wearing of masks, it’s useful to see some comparative data on the relative respiratory protection offered by different mask materials. This study, published years ago (pre COVID!), does just that.

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Please, no gloves to prevent COVID-19

gloves thumbs down

There are rumblings that glove wearing (aka “hand coverings“) are being considered as a widespread recommendation to prevent the spread of SARS-CoV-2 in public places (e.g. shops) in the UK. The message of this post is simple – please, no gloves. Convincing clinical staff of the unintended consequences of glove overuse is tricky enough. But widespread use of gloves in public places like shops may just bring me to tears. (Unless anybody can point me in the direction of solid evidence that this is likely to have a net benefit in reducing transmission…!).

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CPE: seek and ye shall find

We recently published a study in the Journal of Antimicrobial Chemotherapy relating the impact of introducing an enhanced testing* programme for CPE in London. (And yes, this is the first post for a while that isn’t on COVID-19!) Following an outbreak of NDM-producing Klebsiella pneumoniae affecting 40 patients in 2015 (published elsewhere, here and here), we ramped up our CPE testing programme. The number of patients carrying CPE increased substantially, from around 10 patients per month in June 2015 to around 50 per month in March 2018. However, the proportion of tests that were positive for CPE remained constant at around 0.4%, suggesting this was more effective carrier identification rather than a swelling pool of carriers per se; seek and ye shall find! Curiously, the majority of CPE identified were not linked in time and space with other CPE, suggested they represented a ground-swell of CPE coming into the hospital, rather than frequent in-hospital transmission. Also, the number of patients with CPE infections during the study period did not increase, which was reassuring.

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Exploring SARS-CoV-2 hospital surface and air contamination in London

We have just had a study published in Clinical Infectious Diseases exploring the extent and magnitude of hospital surface and air contamination with SARS-CoV-2 during the (first!) peak of COVID-19 in London. The bottom line is that we identified pretty extensive surface and air contamination with SARS-CoV-2 RNA but did not culture viable virus. We concluded that this highlights the potential role of contaminated surfaces and air in the spread of SARS-CoV-2.

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The role contaminated surfaces in COVID-19 transmission: a HIS audience-led webinar

The next instalment of the HIS audience-led webinar series is on the role of contaminated surfaces in COVID-19 transmission. I was delighted to be part of the panel for this one:

  • Dr Lena Ciric – Associate Professor in Environmental Engineering, University College London
  • Dr Stephanie Dancer – Consultant Microbiologist, NHS Lanarkshire and Professor of Microbiology, Edinburgh Napier University, Scotland
  • Dr Manjula Meda – Consultant Clinical Microbiologist and Infection Control Doctor, Frimley Park Hospital
  • Dr Jon Otter – Infection prevention and control Epidemiologist, Imperial College London
  • Chair: Dr Surabhi Taori, Consultant microbiologist and infection control doctor, Kings College Hospital NHS Foundation Trust

Here’s the recording:

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Managing ventilation in the context of COVID-19: a HIS audience-led webinar

The next in the series of the HIS audience-led webinar on all-things ventilation in the management of COVID-19 went out recently. The panel consisted of:

  • Peter Hoffman – Consultant Clinical Scientist, London
  • Dr Chris Lynch – Graham Ayliffe Training Fellow, Sheffield Teaching Hospitals
  • Professor Catherine Noakes – Professor of Environmental Engineering for Buildings, University of Leeds
  • Karren Staniforth – Clinical Scientist, Nottingham University Hospitals NHS Trust
  • Dr James Price (chair) – Consultant in Infection Prevention & Control and Antimicrobial Stewardship, Imperial College Healthcare NHS Trust

The webinar video is below:

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COVID-19 & PPE / face coverings / masks / shields: personal safety depends on more than what you wear

There’s a huge amount of academic and pragmatic discussion and debate about the appropriate levels of PPE to wear in various healthcare settings to reduce the risk of spreading COVID-19 to yourself and others in healthcare settings. And more recently, when to wear face coverings / masks / shields in public areas of hospitals, on public transport, and in shops. However, there is much, much less discussion about the importance of careful doffing (removal) of PPE and face coverings etc in order to ensure the safe and effective use of PPE. This helpful Cochrane Review, updated for the COVID-19 era, covers a lot of ground and one key conclusion is that doffing is key: if it is done carefully, the risk of self-contamination is lower.

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