Hospital wards could become riddled with the coronavirus within the space of just ten hours, according to research.
University College London and Great Ormond Street Hospital scientists tracked the spread of a virus that doesn’t infected humans for five days.
It was placed on a hand rail of a hospital bed in an isolation room, where vulnerable high-risk Covid-19 patients are kept separated.
The scientists then sampled 44 different sites across the same ward, including door handles, arm rests and bed rails.
Four in ten of the surfaces – which included toys and books for children in a waiting area – were contaminated with the virus within ten hours.
It was most detectable three days later, when 60 per cent of samples were positive. The virus began to fizzle out after five days.
Experts emphasised the importance of cleaning and workers sticking to good hand-washing and hygiene practises to curb the spread of the virus.
Hospital wards could become riddled with the coronavirus within the space of just ten hours, according to research. The virus peaked after three days
The researchers, who did not name the hospital studied, used a plant-infecting virus which cannot harm humans for their research.
They placed the DNA of the virus -called cauliflower mosaic virus – into water to replicate SARS-CoV-2 in respiratory droplets, expelled during coughing or sneezing.
Researchers placed the water on the hand rail of a hospital bed in an isolation room on a children’s ward on a Monday morning.
The experts sampled 44 sites on the ward – including clinical areas and the general ward – that evening and over the following five days.
After ten hours, traces of the virus were detected on 41 per cent of sites sampled across the hospital ward.
This increased to 59 per cent of sites after three days and fell to 41 per cent on the fifth day.
This implied a ‘combination of poor cleaning, movement of patients, and carers not adhering’ to frequent hand washing, the paper said.
Dr Lena Ciric, a senior author of the study from UCL, said: ‘Our study shows the important role that surfaces play in the transmission of a virus and how critical it is to adhere to good hand hygiene and cleaning.
‘Our surrogate was inoculated once to a single site, and was spread through the touching of surfaces by staff, patients and visitors.
‘A person with SARS-CoV-2, though, will shed the virus on more than one site, through coughing, sneezing and touching surfaces.’
The virus was most detectable in the clinical area surrounding the first infected bed.
On day three, 86 per cent of sampled sites in clinical areas – which included a nearby room with several other beds – tested positive, highlighting risk to other patients.
On day four, 60 per cent of sampled sites in the immediate bedspace area – such as handrails – tested positive.
People can catch the coronavirus through respiratory droplets produced by an infected person when they cough or sneeze.
If these droplets land on a surface, a person may become infected after touching the surface and then touching their eyes, nose or mouth.
The study showed a single alcohol wipe removed 98.8 per cent of the virus dried on a surface.
Co-author Dr Elaine Cloutman-Green lead healthcare scientist at GOSH, said: ‘Like SARS-CoV-2, the surrogate we used for the study could be removed with a disinfectant wipe or by washing hands with soap and water.
‘Cleaning and handwashing represent our first line of defence against the virus and this study is a significant reminder that healthcare workers and all visitors to a clinical setting can help stop its spread through strict hand hygiene, cleaning of surfaces, and proper use of personal protective equipment (PPE).’
SARS-CoV-2 will likely be spread within bodily fluid such as cough droplets, whereas the study used virus DNA in water.
More sticky fluid such as mucus would likely spread more easily, the researchers said.
A caveat to the study, published as a letter in the Journal of Hospital Infection, is it cannot determine how likely a person would be infected if they touched the surface.
The researchers said there is little guidance for hospitals on how often surfaces should be cleaned.
The virus can last on plastic and stainless steel for up to three days, a study published in the New England Medical Journal found.
But another study from China, published in The Lancet, found traces of the virus on plastic and stainless steel for up to seven days after being left there.
There is growing concern about hospital acquired Covid-19 – that is, people who pick up the coronavirus while in hospital for a different reason.
Up to a fifth of patients with Covid-19 in several hospitals contracted the disease while already being treated there for another illness, The Guardian reported.
In a national briefing in April, NHS England told hospital medics that 10 to 20 per cent of hospitalised Covid-19 had got it while they were inpatients.
Dr Aidan Fowler, director of patient safety at NHS England, said he is ‘concerned about the rates of nosocomial spread within our hospitals,’ the Health Service Journal reported.
Nosocomial infection is that which takes place inside a medical facility.
Healthcare workers can also spread the virus themselves without even knowing they are infected if they don’t show symptoms, which has led to calls for routine testing of all staff.