I had the pleasure of doing a talk at Infection Prevention 2023 in Liverpool today, running down the top 10 scientific articles influencing our IPC practice over the past year. You can download my slides here.

I had some trouble selecting just 10 papers from the past year, and felt a strong sense of my own bias and limitations when going through the selection process. I have my own research and clinical interests, I don’t read anywhere near as many papers as I’d like, and 10 papers really isn’t that many! Also, I tried to countdown the papers from 10 to 1 with some kind of hierarchy. After a couple of false starts here (including the most read, most controversial, best designed), I settled on the most influential in terms of challenging our thinking or modifying our practice.

So, here goes…

11 (I told you 10 wasn’t enough)

Colonisation often precedes infection for MDROs: Has anybody ever said to you “well, the patient has only acquired colonisation and not infection, so it’s not so bad”, or words to that effect? Whilst I understand where they are coming from, this systematic review and meta-analysis shows that colonisation with CPE and VRE often precedes infection. For CP-CRE in particular, this is true for 26% of colonised patients.

10

It’s time to involve patients in our hand hygiene improvement journey: It’s about time we involved patients (and their families/carers) a great deal more than we currently do in co-managing infection risks. A real opportunity for patient involvement is in hand hygiene auditing, especially in settings where traditional observational hand hygiene audits by staff are tricky. This study shows that patient-led hand hygiene audits offer a good solution to get hand hygiene audit data in a 100% ‘consulting room’ style setup.

9

Carbapenem-resistant bloodstream infection is really bad news in ICU – and not all CPE are equal: A nice bit of epi to show that attributable mortality from metallo beta-lactamase producing CRE (that’s the NDMs, VIMs, and IMPs) at 35% is significantly greater than for KPC-producing CRE at 5%. The mechanism for this isn’t clear, but I suspect it has to do with higher levels of expressed resistance to the carbapenems.

8

Improving ventilation is a positive legacy of COVID-19: This opportunities study explored combinations of natural ventilation and portable HEPA filtration to improve ventilation, measured by the removal of aerosolised salbutamol. A combination of HEPA filtration plus window opening achieved an impressive equivalent to 11 air changes per hour. Fresh!

7

The MDRO status of the prior room occupant influences acquisition risk: A favourite topic of mine! It really is true that the acquisition risk of patients admitted to rooms where the previous occupant was infected or colonised with an MDRO, C. difficile, or norovirus is significantly increased, by about 2.5-fold. And, furthermore, if we do a better job of disinfection at the time of patient discharge, this increased risk is mitigated.

6

More effective surface disinfection improves patient outcomes: A really impressive cluster randomised prospective cohort intervention trial found that switch away from a “bucket” chlorine disinfection approach to QAC-based disinfectant wipes significant improved cleaning effectiveness and reduced the acquisition rate of MDROs. Curious, in a way, because “on paper” and in test tubes, chlorine is a more powerful disinfectant that the QAC-based wipes. However, chlorine doesn’t deal well with organic soiling, and wipes make it easier to clean.

5

“Gonna take you right in to the sink splash zone” (duh duh duh): This clever study from Mark Garvey and colleagues at UHB illustrates visually and powerfully the mechanism by which contamination from sinks and drains can make it back to patients. The study shows how far splashed reach from hand washing sinks to define the “sink splash zone”, and then identifies the types of medical equipment found in the zone including vascular access equipment and personal care items in >60%, and patients with IV devices or urinary catheters in >10%.

4

Candida auris: coming to a hospital near you…(& wastewater surveillance is pretty cool): This one is a bit of a double header – sounding the alarm that we need to be prepared for Candida auris, and that wastewater surveillance could have value in providing an early warning surveillance system for C. auris and other infectious diseases.

3

COVID-19 ain’t what it used to be: Remember when Omicron emerged around December 2021, and everybody got COVID-19 at the same time? Well, it was very much not fun trying to manage an IPC service during that period! What we didn’t know at the time, but I am so happy about in hindsight, is that there had been a step-change in clinical harms associated with COVID-19 linked to the emergence of Omicron and the concurrent vaccination campaign. This short and rather descriptive overview of harms linked to Omicron COVID-19 in our hospitals helped us to take the first steps back towards a better-version-of-normal IPC.

2

Horizontal plasmid transfer is a key driver of CPE transmission: Do we want to open this particular Pandora’s Box? Up to this point, we have managed outbreaks of antibiotic-resistant Gram-negative bacteria (mostly) with a “same bacterium, same carbapenemase” (i.e. clonal) lens. But do we need to expands this to a “different bacterium, same carbapenemase” (i.e. plasmid) lens? This detailed genomic analysis of a large set of CPEs in Singapore suggested that ‘traditional’ IPC measures were effective at containing the clonal spread of CPE, but didn’t prevent the spread of plasmid-mediated transmission. So, I think it’s time for us to think differently about this one!

And coming straight in at number 1…

Water-free care demands our attention: There have been a steady stream of papers over the past 5 or 6 years building a compelling case that going “water-free” in delivery care in a critical care setting seems to reduce the spread of antibiotic-resistant Gram-negative bacteria (summarised here). The latest in this series is a retrospective cohort study showing that patients cared for in an ICU with sinks had a significant higher rate of HCAI than patients cared for in ICUs without sinks. Whilst there are some important confounding variables to consider in this study (ICUs without sinks tended to be smaller and care for less complicated patients with a lower risk of HCAI to begin with), it reinforces the case that water-free care demands our attention.