Indoor airborne spread of coronavirus possible: WHO

LONDON: The World Health Organization (WHO) on Thursday, July 9, acknowledged the airborne transmission of coronavirus under certain conditions after 239 scientists raised concerns and urged the agency to do so. The UN health agency also underlined that more evidence in terms of research of airborne transmission was required.

Two scientists from Australia and the US wrote in an open letter published in a journal this week that studies have shown “without any reasonable doubt that viruses are released during exhalation, talk and coughing in microdroplets that are small enough to remain aloft in the air”. The researchers, along with more than 200 others, called for more stringent protective measures to be taken by national and foreign authorities, including WHO.

WHO has long ignored the idea of spreading the coronavirus in the air except for certain dangerous medical treatments, such as when patients are first placed on breathing machines. In a shift to its previous thinking, WHO recognized that studies evaluating COVID-19 outbreaks in restaurants, choir practices and fitness classes suggested that the virus might have spread in the air.

WHO said that airborne transmission, especially in specific indoor environments, such as crowded and inadequately ventilated spaces where an infected has been for a quite long period of time cannot be ruled out. However, officials have pointed out that other transmission mechanisms like “contaminated surfaces or near interactions between people in these indoor settings” may also explain the spread of the disease.

The agency said that the majority of the transmission is by droplets from infected individuals who cough or sneeze but noted that people without symptoms may also transmit the disease. WHO has been repeatedly saying asymptomatic transmission is rare and its extent in the community is unknown despite the fact that many scientists globally agree that such spread likely accounts for a significant amount of transmission.