A little while ago I blogged about the excellent study from Nottingham that demonstrated significant VRE and MRSA contamination on socks used to prevent falls in the hospitalised elderly. This has been followed by another paper suggesting that shoe coverings undurprisingly become contaminated. So, what? How does this really impact on transmission? A new study from Curtis Donskey’s group has looked at hand contamination in patients directly relating to floor contamination.Just published in ICHE, this study has mimiced one of my favourite papers, the excellent Oelberg paper on examining transmission by use of a surrogate and really does bring into question the long-held apathy with regards to floors as a potential source of transmission.In this recent study, Koganiti and colleagues used bacteriophage MS2, a nonpathogenic, nonenveloped RNA virus to look at the potential transfer from floors onto high-touch surfaces and to hands of patients (not staff – I am wondering if there is another paper to come on this). For each patient, a 30×30 cm sq area of flooring was inoculated and floors were only cleaned when ‘visibly soiled’. The results were interesting to say the least. On day 1, 40% of patients had evidence of contamination on their hands. On day two, the contamination rate rose to 62.5% before falling back to 43% on day three. 77% of high touch surfaces less than three feet from the bed were contaminated by day 3 (starting from a lowly 58% on day 1..). By day two, the virus was found in 100% of adjacent rooms and by day 3 63% of samples on nursing stations were contaminated (keyboards etc).

As these authors point out, the study is useful in demonstrating the utility of these surrogates in examining potential routes of transmission. I also think that it gives us further reason to promote hand hygiene by patients, especially at critical times such as before eating (as if we really needed one).