It is Time to Address Airborne Transmission of COVID-19 (Clinical Infectious Disease, 6 July)
239 scientists support this Commentary
Potential for airborne spread of COVID-19
Significant potential for inhalation exposure
Microscopic respiratory droplets (microdroplets)
Viruses are released during exhalation, talking, and coughing in microdroplets
Small enough to remain aloft in air
5 μm droplet will travel tens of meters
Transmission via airborne microdroplets is an important pathway
Hand washing and social distancing are appropriate, but insufficient
Viruses have been shown to survive equally well, if not better, in aerosols compared to droplets on a surface
Several superspreading events
We must address every potentially important pathway to slow the spread of COVID-19
Measures that should be taken
Provide sufficient and effective ventilation (supply clean outdoor air, minimize recirculating air) particularly in public buildings, workplace environments, schools, hospitals, and aged care homes.
Supplement general ventilation with airborne infection controls such as local exhaust, high efficiency air filtration, and germicidal ultraviolet lights.
Avoid overcrowding, particularly in public transport and public buildings.
WHO response
Transmission through smaller droplet nuclei (airborne transmission) that propagate through air at distances longer than 1 meter is limited to aerosol generating procedures during clinical care of COVID-19 patients.
In all other contexts, available evidence indicates that COVID-19 virus is transmitted during close contact through respiratory droplets (such as coughing) and by fomites.
WHO continues to recommend
Everyone performs hand hygiene frequently
Follows respiratory etiquette
Regularly clean and disinfect surfaces
Maintaining physical distances
Avoiding people with fever or respiratory symptoms
These preventive measures will limit viral transmission
WHO, However
We are also looking at the possible role of airborne transmission in other settings
We will be releasing our brief in the coming days
We acknowledge there is emerging evidence in this field
Therefore, we believe we have to be open to this evidence and its implications
Determining the dose of the virus required for airborne transmission
These fields of research are really growing but not definitive
The possibility of airborne transmission in public settings — especially closed, poorly ventilated settings — cannot be ruled out
Importance of removal of the virus-laden droplets from indoor air by ventilation
