Way back during the first wave of COVID-19 (April 2020), we got our swabs out and sampled surfaces and air across a range of settings in the hospital. This cross-sectional study identified SARS-CoV-2 RNA on a rather startling 52% of surfaces and 45% of air samples collected from across the hospital and some public areas. During the second wave (January 2021), we undertook a similar exercise, and identified a vastly different level of contamination with SARS-CoV-2 RNA: 5% of surfaces and 4% of air samples. What had changed between April 2020 and January 2021 to explain this difference? A whole host of things, and we don’t know for sure – but I suspect that improved testing availability and the introduction of masks for staff and patients were the most important factors.
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What’s trending in the infection prevention and control literature? HIS 2012 -> HIS 2014
I was privileged to speak at the Healthcare Infection Society meeting in France today on ‘What’s trending in the infection prevention and control literature? HIS 2012 -> HIS 2014’. You can download my slides here, and view the recording below:
I have always enjoyed attending these light-hearted summary sessions at other conferences, so I hope I struck the right tone. In order to track some of the trends in the infection prevention and control literature since the last HIS conference (in late 2012), I plugged some search terms into Google trends (Figure).
Figure: Google Trends for all search terms (excluding viruses) (2004 to present). Logos and arrows represent the time of the HIS 2012 and HIS 2014 conferences. Search terms: hospital cleaning; carbapenem resistant Enterobacteriaceae, whole genome sequencing, fecal microbiota transplantation. [Note, I had to spell it ‘wrong’ (fecal v faecal) to detect a trend. Blasted Americans.]
Based on my search terms, there was one infection control trend that trumped all others: Ebola. If I include in with the other Google search terms, it eclipses all others! Whilst trends in Google searches may not necessarily correlate with trends in the infection prevention and control literature, in this case, it is true that the outbreak of Ebola in West Africa has prompted a lot of publications in the literature – and consumed an awful lot of professional time for all who are connected with hospital infection prevention and control! Aside from Ebola, other trends in the infection prevention and control literature that I covered include MERS-CoV, universal vs. targeted interventions, faecal microbiota transplantation, whole genome sequencing, carbapenem-resistant Enterobacteriaceae (CRE), and some aspects of environmental science. Finally, I looked into my crystal ball and predict some of the trends in the infection prevention and control literature by the time HIS 2016 comes around.
Journal Roundup September 2014: Ebola, Environmental science, and MDR-GNR
Another month, another Journal Roundup (free and open acces in Journal of Hospital Infection). This month, Ebola tops the bill as the outbreak continues unabated, it seems inevitable that repatriations of healthcare workers from West Africa will continue and increase. The big journals discuss the appropriate level of PPE, and how to test experimental medicines, amongst other things.
A number of useful environmental science updates feature in the Roundup. For example, an age-old question is whether contaminated hands or surfaces contribute most to transmission. A modeling study found that improvements in hand hygiene compliance are about twice as effective in preventing the transmission of multidrug-resistant organisms compared with improvements in environmental hygiene. So hands are more important right? Well, as the single most important intervention to prevent transmission, then yes.
Several studies on the theme of multidrug resistant Gram-negative rods (MDR-GNR) serve mainly to highlight the limitations in the evidence base for establishing what works to prevent MDR-GNR. One of the major problems here is that ‘MDR-GNR’ is a heterogeneous group comprised of several species and resistance mechanisms, not to mention strain variation. The prevention and control prospects for MDR-GNR are different to pathogens like MRSA, VRE and C. difficile. You need to cover all bases – and there are more bases to cover!
The Reviews and Guidelines section includes a thoughtful piece considering the “hygiene hypothesis” vs. the idea of “biome depletion”, the inadequate level of funding in HCAI research, infection control practice in the ER, the cost of CDI, prospects of phage therapy and interrupting regulatory RNA function.
And finally, a UK study finds pretty high levels of ATP on the beverage trolley. So time to ban the beverage trolley as an infection control risk (along with flowers, pets and child visitors)? Not yet – it’s not that surprising to find ATP (which may originate from food, not microbes) on a beverage trolley. That said, if they’d found a lot of MRSA or, worse, CRE then I’d think twice about a cuppa!
Image credit: CDC Global.
Keep your hands to yourself
An article in the American Journal of Infection Control evaluates the acquisition of Clostiridium difficile spores on the gloved hands of healthcare personnel (HCP) following contact with environmental surfaces and patients. The work was performed by Guerrero et al. in Curtis Donskey’s team at the Cleveland VA hospital. The prospective study included 30 patients with C. difficile infection. The hands of HCP were effectively used to sample surfaces on patients’ skin and from the inanimate environment. The key findings is that there was no significant difference between the rate of contamination of HCP hands when touching the patient as compared with touching environmental surfaces (50% for both). Although the concentration of spores acquired on the hands was lower for environmental surfaces than for patient sites, there was not a significant difference.
The study evaluated the proportion of various environmental and patient sites that transferred C. difficile spores to the gloved hands of HCP, which ranged from 20% to 50% for both patient and environmental contacts.
This study follows other that have examined the proportion of contacts with either patients or surfaces that result in HCP hand contamination. These studies have shown that the risk of acquiring hand contamination when touching a patient or a surface is approximately equal for MRSA and VRE.
These studies highlight the complex interplay between the hands of HCP, patients and their inanimate environment. It seems likely that a substantial proportion of transmission between patients occurs indirectly through contact with environmental surfaces. For example, a study published in 2000 evaluated the spread of a non-microbial marker (plant DNA) designed to model the spread of pathogens from hospitals surfaces. The marker was inoculated onto a single telephone handle in one of six 8-cot ‘pods’ in a neonatal intensive care unit. The spread of the marker was remarkable: within four hours it was identified from environmental surfaces and staff hands across the unit including all six pods. While the spread of plant DNA does not necessarily accurately represent the spread of a pathogenic micro-organism, it does present a picture of dynamic and rapid transmission involving both environmental surfaces and staff hands.
There has been much discussion around whether to focus on improving environmental cleaning and disinfection or compliance with hand hygiene. These studies demonstrate that there is a need to improve both environmental and hand hygiene in order to maximize patient safety.
Article citation: Guerrero DM, Nerandzic MM, Jury LA, Jinno S, Chang S, Donskey CJ. Acquisition of spores on gloved hands after contact with the skin of patients with Clostridium difficile infection and with environmental surfaces in their rooms. Am J Infect Control 2012;40:556-558.
Reflections on Infection Prevention and Control 