Safe surfaces

Editor – Embarrassing stories are ubiquitous when it comes to early experiences in theatre. As a fairly fledgling surgeon myself, I still remember scrubbing for the first time. Watching carefully, I copied the consultant's every move, entered theatre, let out a sigh of relief and stabilised the stool as I sat. An experienced scrub nurse saw me touch the non-sterile surface and informed me immediately of my faux pas.

A similarly authoritative figure recently served me in the supermarket. Well meaning, I'm sure, he scalded me for standing too close as I packed my bags. Bizarrely, he seemed unperturbed by handling every item as it passed through the scanner. My basket was then immediately picked up by the next customer as I left the store. Surfaces were not of concern, only the ‘2-metre rule’.

To the nation's credit, behaviour in such public places is almost unrecognisable. Most are receptive to social distancing advice and even seem to have overcome their instinctive reaction to hoard toilet rolls. However, many seem oblivious to the potential risks of handling every packet in search of the best sell-by-date. Surface hygiene is undoing otherwise good precautionary behaviours.

The environmental spread of COVID-19 is undoubtedly multi-modal. Avoiding airborne droplet transmission is merely one weapon in our arsenal. SARS-CoV-2's ability to survive on dry surfaces extends into hours. Its half-life on plastic, such as the handle of a supermarket basket, is >6 hours, compared with 1.2 hours in aerosol form.¹ While observed viral decay is exponential, this is unlikely to negate the risk posed by regularly handled surfaces.¹

It unfortunately matters little how frequently people are washing their hands if they are rapidly ‘recontaminated’. While employers are instructed to disinfect high-touch surfaces within public spaces, to do so between each person is impossible.² As such, behavioural changes to limit contact are imperative to mitigate the inevitable associated risk. The same absent-minded contact that led me to reposition a theatre stool is driving people to pick the basket at the top of the pile.

Public perception over how to stay safe from COVID-19 seems dramatically skewed towards avoidance of airborne droplets. The motivation to stay safe is undoubtedly present but, without understanding, it can be so easily misguided. We have recently read Greenhalgh and colleagues' ‘call to arms’ for the public to wear face masks as a precautionary principle.³ Do we not also need to better address the other main means of transmission? We need safer surfaces.