Does coronavirus spread through air via normal breathing?

The novel coronavirus might spread through air via normal breathing and speaking , a top us scientist said on Friday as the Centre for Disease Control in America asked everyone to use face masks for everyone. Anthony Fauci, head of infectious diseases at the National Institutes of Health (NIH), told Fox News the guidance on masks news would be changed "because of some recent information that the virus can actually be spread even when people just speak, as opposed to coughing and sneezing". Earlier, as per the guidelines only sick people need to cover their face by masks or those caring for them at home.

Findings

Fauci's comments come after the National Academy of Sciences (NAS) sent a letter to the White House on April 1 that summarised recent research on the subject. The result of the research are not yet conclusive and results are consistent with aerosolization of virus from normal breathing. According to US health agencies the primary pathway of transmission is respiratory droplets, about one millimeter in diameter , expelled by sick people when they sneeze or cough.

These quickly fall to the ground around a meter away. But if the virus can be suspended in the ultrafine mist we expel when we exhale, in other words aerosol, it become much harder to prevent its spread, which in turn is an argument in favour of everyone covering their faces.

The aerosol debate

A recent NIH funded study published in the New England Journal of Medicine found that the SARS-COV-2 virus could become an aerosol and remain airborne for up to three hours. This triggered a debate even as critics said that the findings are over blown because the team behind the study used a medical device called nebulizer to intentionally create a viral mist and argued this would not occur naturally.

The NAS letter pointed to preliminary research by the University of Nebraska Medical Center of the SARS-COV-2 virus, its RNA , were found in hard to reach area of patient's isolation rooms. The NAS scientist also pointed out two other studies from Hong Kong and from mainland China.

Details of China's study

Hong Kong researchers collected viral samples from patients with the coronavirus and other viral respiratory illnesses, and gave some patients face masks. The masks reduced the detection of both droplets and aerosols for coronavirus patients. The Chinese paper on the other hand raised concerns that personal protective gear used by health care workers could itself be a source of airborne virus. The team studied the hospital in Wuhan and found that there were two major areas where the virus was aerosolized , the bathroom of patients and rooms where medical staff removed their protective gears.

WHO take on this research

So far, WHO has been more cautious on the airborne threat. In an analysis published on March 29, it wrote that aerosol transmission was only know to occur during particular medical treatment that required assisted breathing. On the recent preliminary research , such as the University of Nebraska's paper, the WHO cautioned that the detection of the virus genetic code in patient's room did not necessarily amount to viable amounts of the pathogen that could be transmitted onward.

Divya Rawat is an intern with SheThePeople.TV