Coronavirus found in oxygen samples up to 4 metres from patients: China study
12 April, 2020
A new study examining air samples from hospital wards with COVID-19 patients has found the virus can travel up to 4m - twice the distance current guidelines say people should keep between themselves in public areas.
The preliminary results of the investigation by Chinese researchers were published on Friday in Emerging Infectious Diseases, a journal of the US Centers for Disease Control and Prevention (CDC).
They add to an evergrowing debate on how the condition is transmitted, with the scientists themselves cautioning that the small levels of virus they bought at this distance aren't necessarily infectious.
The researchers, led by a team at the Academy of Military Medical Sciences in Beijing, tested area and air samples from a rigorous care unit and an over-all COVID-19 ward at Huoshenshan Hospital in Wuhan. They housed a total of 24 people between Feb 19 and Mar 2.
They discovered that the virus was most heavily concentrated on the floors of the wards, "perhaps as a result of gravity and airflow creating most virus droplets to float to the bottom".
High levels were likewise entirely on frequently touched surfaces just like computer mice, rubbish bins, side rails and doorknobs.
"Furthermore, 1 / 2 of the samples from the soles of the ICU medical personnel shoes tested confident," the team wrote. "Subsequently, the soles of medical staff shoes might function as carriers."
AIRBORNE THREAT?
The team also looked at so-called aerosol transmission - when the droplets of the virus are so fine they become suspended and remain airborne for several time, unlike cough or sneeze droplets that fall to the bottom within seconds.
They discovered that virus-laden aerosols were mainly concentrated near and downstream from patients at up to 4m - though smaller quantities were found upstream, up to 2.4m.
Encouragingly, no members of a healthcare facility staff were infected, "indicating that appropriate precautions could properly prevent infection", the authors wrote.
In addition they offered advice that bucks orthodox recommendations: "Our findings advise that home isolation of people with suspected COVID-19 may not be an excellent control strategy" given the levels of environmental contamination.
Aerosolisation of the coronavirus is a contentious place for scientists who review it, because it isn't sharp how infectious the disease is in the tiny quantities within ultrafine mist.
The World Health Corporation has up to now downplayed the risk.
US health authorities have followed a more cautious series and urged persons to cover their faces when away in public in the event the virus can be transmitted through normal breathing and speaking.
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