By Dr. Edsel Salvana (Clinical Associate Professor, University of the Philippines)
MANILA — There is a lot of discussions on the airborne transmission of COVID-19.
This isn’t a new issue but there has been more news coverage and, unfortunately, there is also a lot of noise.
This is what we know:
1. SARS-CoV-2 can be airborne in specific situations
The most common situation is in the hospital when healthcare workers do aerosol generating procedures such as suctioning, intubation or procedures that involve the upper airway. The best protection for these situations is use of appropriate PPE including N95 masks as well as proper airflow exchanges and ventilation. This is not under debate and we have been doing this in the hospital every since the start of the pandemic.
It is less clear if this happens outside the hospital, but there has been some data showing generation of smaller sized particles when people cough with the potential to travel greater distances and stay in the air for longer periods of time.
2. Smaller droplets that can remain airborne don’t necessarily contain enough virus to infect someone
While we know the bigger respiratory droplets that drop off to the ground after 1 meter carry enough virus to infect other people, the smaller droplets that carry beyond that distance may not necessarily have enough virus to cause infection. This is an area of active research. This is important because it doesn’t necessarily follow that just because there are small particles that those particles are infectious.
3. Do I need to wear an N95 mask?
N95 masks only work well if they are specially fitted and there are different sizes. They are also very uncomfortable for long periods of time and are expensive. An N95 that is not properly fitted is no better than a surgical mask. Studies have shown that surgical masks already decrease risk of transmitting COVID-19 by 85%. There is not enough evidence that N95 masks will be useful for the general public.
4. So what does this renewed debate mean for the general public?
It means that we have to be extra careful with COVID-19. It means that because COVID-19 has the potential to have airborne characteristics – hang out in the air longer, go beyond 3 to 6 feet – we have to be meticulous with cloth or surgical mask wearing and minimize crowding especially in areas with poor ventilation. Avoid talking without a mask, especially in enclosed spaces like elevators. Singing has also been implicated in super-spreader events so no karaoke for now. Do not eat together at work as this has also been associated with clusters.
This possibility of airborne transmission is not new, and even if the evidence is far from definitive, it is always prudent to take precautions – within reason. There is no need to use N95 masks unless you are a healthcare worker, but everyone else needs to be meticulous with cloth or surgical mask wearing. Avoid crowded areas and enclosed spaces with poor ventilation. Limit trips outside the house and practice physical distancing, work from home if possible, and disinfect regularly. COVID-19 is beatable if we all work together and if everyone does the right thing to protect each other.