Coronavirus Update: WHO issues new Guidelines on Airborne transmission of COVID-19

On Thursday the World Health Organization (WHO) released new guidelines on the transmission of the novel coronavirus, that acknowledged the COVID-19 virus has the potential to spread via air but at the same time stated that high-quality research is urgently required to understand the matter.

In its latest transmission guidance on COVID-19, the WHO acknowledged that some outbreak reports related to indoor crowded spaces (like in restaurants, fitness classes, or health care settings) have suggested the possibility of aerosol transmission.

However, the WHO stated that more research is urgently needed to emphasize the importance of different transmission routes of the coronavirus.

Based on its earlier study of evidence, the WHO said that the coronavirus spread primarily through direct, indirect, or close contact with contaminated surfaces or by the infected individual who spread the virus through saliva, respiratory secretions or droplets released when an infected person coughs, sneezes, or speaks.

The new transmission guidelines, however, suggest people should avoid crowded places and ensure good ventilation in buildings.

WHO emphasized that high-quality research is urgently required to understand the role of airborne spread of the COVID-19 virus. The experts have described aerosols as being under 5 microns because only particles with that small size can float in the air so long to be inhaled.

What are aerosols?

Coronavirus Update: WHO issues new Guidelines on Airborne transmission of COVID-19

Basically, aerosols are minute particles that are discharged under pressure, like the fine mist from perfume jar, and the diameter of these particles is considered as 5μm or less.

Aerosol particles could include fine dust, mist, or smoke and the size of these particles are much smaller than respiratory droplets and take a longer time to drop to the floor.

As per the open letter, a 5-micron aerosol droplet can travel tens meters, which is much greater than the scale of a typical room, while settling from a height of 1.5 m to the floor.

As these 5-micron droplets remain suspended in the air for a longer time, it is more likely that an infected individual can spread the virus even standing at a distance of 1-2 m in a small, poorly ventilated room.

Difference between airborne and droplet transmission

Airborne transmission

Droplet transmission

Airborne is less than 5 micrometres

Droplet is more than 5 micrometres

Airborne material can travel up to 6-9 feet

Droplets settle on some surfaces

Can transmit by an infected person breathing, laughing or singing

Can transmit if an infected person coughs, sneezes, or speaks

They remain suspended in the air for longer

They settle down on some surfaces


What you can do to prevent respiratory infections:

In this current situation, it’s always best to wear a mask while going out in public settings to keep respiratory infections away.

Always try to keep at least 3 feet of physical distance and wash hands frequently with soap and water.

Do not touch your face frequently and practice respiratory etiquette.

Avoid crowded areas, close-contact surroundings, and confined and enclosed places with poor ventilation.