As almost the whole world is under lockdown so that the spread of the Coronavirus could be stopped from spreading, a new study examining air samples from hospital wards with COVID-19 patients has found the virus can travel up to 13 feet (four meters), twice the distance current guidelines say people should leave between themselves in public while implementing social distancing.
An investigation by Chinese researchers, the preliminary results of which were published on Friday, in ‘Emerging Infectious Diseases’, a journal of the US Centers for Disease Control and Prevention (CDC) add to a growing debate on how the disease is transmitted, with the scientists themselves cautioning that the small quantities of virus they found at this distance are not necessarily infectious.
While, testing surface and air samples from an intensive care unit and a general COVID-19 ward at Huoshenshan Hospital in Wuhan, the researchers, led by a team at the Academy of Military Medical Sciences in Beijing, tested surface and air samples from an intensive care unit and a general COVID-19 ward housing a total of 24 patients between February 19 and March 2.
The scientists found that the virus was most heavily concentrated on the floors of the wards, “perhaps because of gravity and air flow causing most virus droplets to float to the ground.”
High levels were also found on frequently touched surfaces like computer mouse, trashcans, bed rails and door knobs. “Furthermore, half of the samples from the soles of the ICU medical staff shoes tested positive,” the team wrote. “Therefore, the soles of medical staff shoes might function as carriers.”
The team also looked at the aerosol transmission, in which the droplets of the virus are so fine they become suspended and remain airborne for several hours, unlike cough or sneeze droplets that fall to the ground within seconds.
They found that virus-laden aerosols were mainly concentrated near and downstream from patients at up to 13 feet — though smaller quantities were found upstream, up to eight feet.
Encouragingly, no members of the hospital staff were infected, “indicating that appropriate precautions could effectively prevent infection,” the authors wrote.
They also offered advice that bucks orthodox guidelines, “Our findings suggest that home isolation of persons with suspected COVID-19 might not be a good control strategy” given the levels of environmental contamination.
Aerosolization of the coronavirus is a contentious area for scientists who study it, because it is not clear how infectious the disease is in the tiny quantities found in ultrafine mist.
Although, the World Health Organization has so far downplayed the risk but the US health authorities have adopted a more cautious line and urged people to cover their faces when out in public in case the virus can be transmitted through normal breathing and speaking.
The novel Coronavirus is primarily transmitted through “respiratory droplets and close contacts” and does not seem to stay long in the air, said the World Health Organisation (WHO) in a recent publication.
Respiratory infections can be transmitted through droplets of different sizes, according to the WHO.
Social distancing is recommended because droplet transmission occurs when you have close contact (within one metre) with a person who has respiratory symptoms such as coughing or sneezing, which may spread these potentially infectious droplets, typically 5-10 microns in size, to your body.
Meanwhile, global Coronavirus deaths have increased to 102,753, while the total number of cases worldwide has surpassed 1.6 million as countries greet Easter weekend.
(With inputs from AFP)