Your advice on how to protect yourself against coronavirus (Report, 2 March) does not mention the benefits of opening a window.

Modern hospitals try to kill, remove or constrain pathogens with high-energy systems using air extraction, high temperature sterilisation and ultraviolet, but the low-tech solution of simply opening windows can reduce cross-contamination between patients within, or between, wards.

Traditional hospitals were built with high ceilings and large windows to ensure the removal of infectious pathogens away from patients. Research has shown demonstrably lower cross-infection rates for airborne respiratory diseases, like tuberculosis (or Covid-19) in naturally ventilated, rather than mechanically ventilated wards. Scientifically robust studies have also shown that pressurised ventilation and drainage systems have been linked to the spread of a range of infectious diseases including MRSA, MDRBT, Sars, TB, influenza, chickenpox and measles in a range of different building types, sometimes caused by faulty mechanical systems, inaccessible ducts, poor maintenance, or physical and managerial factors that influence the transmission rates through ducts, and between occupants.

All hospitals should have naturally ventilated wards. All buildings should have openable windows. Why don’t they – pandemic or no pandemic?

Susan Roaf

Emeritus professor of architectural engineering, Heriot Watt University

• I read in a recent report that “delay into the summer months also may reduce the intensity of the epidemic, because people open windows and go outdoors, where they are much less likely to be infected” (Coronavirus UK: U-turn over plan to stop daily geographical updates, 5 March).

In 1975 I worked as a junior doctor at the Royal Free hospital infectious disease unit, then at Coppetts Wood hospital, and I remember that windows in the TB ward were opened on ward rounds to improve air flow and reduce the spread of TB. More recently, I saw the same routine in Uganda. So I am surprised that the intervention of fresh air and increased air flow to reduce Covid-19 infection does not appear to be mentioned in the advice to the public. Perhaps there is a wait for ethical approval, controlled trials and the evidence base but surely fresh air is unlikely to cause harm. Meeting friends for a walk in the fresh air, rather than indoors, would seem to be likely to reduce infection risk and could be added to the already long list of health benefits of walking.

Jill Vines

Frampton, Dorset

• If washing the hands is effective, then regular disinfectant wiping of surfaces must also be important. The health advice to organisations that have premises open to the public should be that regular “hygiene walks” around premises wiping door handles, light switches, hand rails and the like should be mandatory.

Owners of shops could be proactive by instituting such regular hygiene walks and being seen to be doing so. Hand gel stations at entrance doors might be another reassurance to the public.

Lyn Summers

Lancaster

• Professor Kelly (Letters, 9 March) might be reassured by the fact that the hand-washing message has surprisingly reached that most recalcitrant of targets, the football fan at the gents’ urinals at Pride Park stadium, Derby. On Sunday, alerted by the unprecedented queues for the hand basins, my ad hoc survey showed about 90% usage. This in my view is at least a threefold increase on normal. Most were making a passable attempt at Boris Johnson’s Happy Birthday technique.

Chris Osborne

West Bridgford, Nottinghamshire

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