(Video Animation and Editing: Puneet Bhatia)
(A recent study published in the Lancet points to strong evidence that COVID-19 causing SARS COV 2 virus which was thought to spread through droplets, is primarily an airborne pathogen. FIT is republishing this explainer in this light.)
On 8 July, the World Health Organization acknowledged that there is “emerging evidence” that the novel coronavirus may be airborne after an open letter by 239 scientists asked the agency to revise its guidelines.
The scientists have urged that with significant evidence emerging for smaller or bigger particles remaining in the air, the safety and precautionary protocols would have to be updated to cater to airborne transmission as well.
But what does this mean and how does it change our understanding of the virus? FIT explains through an explainer video.
How Does the Virus Spread?
A respiratory infection like COVID-19 is spread by droplets expelled when an infected person coughs, sneezes or speaks.
These droplets can be of varying sizes. The relatively bigger and heavier ones do not travel far or remain in the air. This is why maintaining a distance of nearly two metres or six feet is advised.
These droplets sink to the ground or on objects and surfaces. People can become infected by touching these objects or surfaces, then touching their eyes, nose or mouth. This is why it is important to wash your hands regularly with soap and water or clean with alcohol-based hand rub, according to the WHO and other public health agencies.
The WHO had, since the beginning of the pandemic, been asserting the spread of the virus through these bigger droplets released when an infected person coughs or sneezes.
How Does It Stay in the Air?
There is now mounting recognition that the virus can remain suspended in the air in smaller, tinier droplets called aerosols. These aerosols can be released even when an infected person breathes or talks. Anyone who inhales the same air can catch the disease.
This could explain how asymptomatic people who do not necessarily sneeze or cough could be carriers of the infection.
We don’t know for sure for how long the virus lingers. Experts agree that aerosols may not travel long distances or remain viable outdoors, The New York Times reported. But crowded spaces and poorly ventilated indoors could be breeding grounds for infection.
For instance, a single person can release enough aerosolized virus over time to infect many people in a closed room.
But aerosols are smaller in size, so they contain lesser virus than big droplets. Even the tiniest measures can help.
How Do I Stay Safe?
- To put it simply: Wear your mask.
- Physical distancing and handwashing are still extremely important. But they may not be enough.
- Preventing airborne transmission would mean avoiding crowded indoor spaces as much as possible.
- If you do spend time indoors, do not forget to wear a mask, except maybe around family and friends who you know have stayed safe.
- Ensure enough fresh air is circulating through a room.
- Open windows and doors as much as possible.
- If you can, upgrade the filters in your home air-conditioning systems.
- If schools, offices, malls and stores reopen, the ventilation systems may need to add powerful new filters to avoid recirculating the same air.
- In the right setting, the use of ultraviolet lights that can kill the virus may also be considered to prevent transmission through smaller droplets.
- Remember, stagnant air inside closed doors could be your enemy.