The new coronavirus can possibly be transmitted through the air in crowded indoor settings with poor ventilation such as restaurants, gyms, night clubs and offices, the World Health Organization (WHO) has said, as lockdown restrictions are being eased globally.
The health agency on Thursday published an updated scientific brief on the different modes of transmission of COVID-19, the highly contagious respiratory disease caused by the coronavirus, identifying the different locations and circumstances of virus spread.
According to the WHO, the coronavirus is primarily transmitted by droplets through direct or close contact with an infected person and indirect contact through contaminated surfaces, also known as fomite transmission.
But the possibility of airborne transmission, combined with droplet transmission, cannot be ruled out in specific settings and more research is needed, it said.
In an exclusive interview with Al Jazeera, the WHO’s technical lead on COVID-19, Maria Van Kerkhove, and the agency’s chief scientist, Soumya Swaminathan, talked about the possible ways of COVID-19 transmission, the risks and the preventive measures.
Al Jazeera: Can you explain how airborne transmission takes place exactly and under what circumstances and environments does it pose a higher risk?
Maria Van Kerkhove: Airborne transmission has to do with the size of the droplets that are expelled from people, how long they can be suspended in the air and the distance they can potentially travel. Because they are lighter than respiratory droplets, they can travel through the air further than heavier droplets that tend to fall to the floor much quicker.
We know there can be aerosol transmission in healthcare settings where specific medical procedures, called aerosol generating procedures, are conducted on sick patients.
There’s also the possibility that there could be these smaller particles that come out of people’s mouths when they talk, sing and engage in fitness activities.