A year after the pandemic, the World Health Organization updated its health advisory last April, stating that COVID-19 may be acquired through airborne transmission. This is in addition to the droplet transmission, which was previously the widely recognized mode of spreading the virus.
But what does this new discovery entail? Panahon TV sought the advice of Dr. Rontgene Solante, chairman of the Adult Infectious Diseases and Tropical Medicine Department at the San Lazaro Hospital, and a member of the Vaccine Expert Panel of the Department of Science and Technology.
Droplet vs Airborne Transmission
Dr. Solante mentioned that the COVID-19 virus is expelled through coughing, sneezing, or talking. The Centers for Disease Control and Prevention (CDC) adds to this list by stating that “People release respiratory fluids during exhalation (e.g., quiet breathing, speaking, singing, exercise, coughing, sneezing) in the form of droplets across a spectrum of sizes. These droplets carry virus and transmit infection.”
“The droplet is composed of virus particles within the saliva,” explained Dr. Solante in a mix of English and Filipino. “This means it’s much bigger and heavier. When you cough or sneeze, the droplet can travel up to 3 feet. It falls quickly on surfaces.” It’s because of these reasons why COVID-19 prevention involves regular hand washing and regularly disinfecting frequently-touched surfaces.
On the other hand, COVID 19’s airborne transmission involves the aerosolized form of the virus. “Why is it aerosolized? It’s because when you cough, you expel not just droplets but also tinier particles. These particles are lighter so they stay in the air longer. This is what we call airborne.”
While droplets are most infectious within a 3-feet or 1-meter distance between people, the airborne particles, which can remain suspended in the air for up to two to three hours, may infect people within an 8-feet distance.
According to the World Health Organization (WHO), medical procedures and treatments that produce aerosols may also transmit COVID-19. These include endotracheal intubation, open suctioning, administration of nebulized treatment, manual ventilation before intubation, turning the patient to the prone position, and disconnecting the patient from the ventilator.
The CDC states that the higher the amount of virus a person is exposed to, the higher the risk of infection. Through the airborne transmission, you are more likely to catch COVID-19 when the following factors are present:
- Enclosed spaces with poor ventilation. This includes air-conditioned spaces that let droplets and aerosol particles build up in the air.
- Increased exhalation of an infected person’s respiratory fluids. This person doesn’t need to cough or sneeze to spread the virus. He or she may simply be shouting, singing or engaged in a form of physical exertion such as an exercise.
- Prolonged exposure to these conditions for more than 15 minutes.
Though bikers are required to wear face masks, they do not have to wear face shields as these pose safety risks according to the Department of Health. (photo by Jire Carreon)
What Airborne Means
“Airborne diseases are easily transmitted when you are not wearing the proper face mask, when ventilation is very poor, and more importantly, when you are in a closed space,” warned Dr. Solante. Tuberculosis is an example of an airborne disease. “The reason why the Philippines has a high case of Tuberculosis is because many of us live in communities with houses built close to each other. When one has this disease, he or she is likely to transmit it to family members. In a way, this is similar to COVID-19, which easily spreads within the household because of the droplet and airborne modes of transmission.”
The fact that COVID-19 is airborne and may be transmitted beyond 6 feet only means that more than ever, we need to be vigilant about health protocols, and stay in well-ventilated areas. Dr. Solante said, “Chances are, if you are in a room without ventilation or with poor ventilation, the virus can stay longer— for about 3 hours. The minute you remove your face mask or face shield, then you can get the virus within 15 minutes of staying in that closed space.”
But what does proper ventilation mean? Dr. Solante said this is achieved when air inside the room is able to flow out, while air outside the room is able to flow in. “Without air ventilation, the aerosolized virus can stay in the air for two to three hours. But if you open the windows, and there’s ventilation, the virus will only be airborne for less than 15 or 30 minutes, as long as there are only a few people inside the room.”
Sign inside a jeepney. This year, face shields were also required inside public transportation. (photo by Paul Michael Caisip)
How to Prevent Airborne Transmission of COVID-19
Dr. Solante offers these prevention tips in various settings:
- Open windows to encourage ventilation.
- If the heat is too much, and you want to turn on the air-conditioning, make sure to have less conversations and interaction among family members inside the room. Wear face masks, and limit the number of room occupants.
In the office
- Maintain a distance of at least six feet from other people.
- Limit the number of people in the room.
- Always wear your face mask and face shield inside the room. Dr. Solante doesn’t recommend doubling your masks as this may make breathing difficult.
- Avoid unnecessary talking. Use chats or other forms of communication that don’t require you to open your mouth.
- Always practice cough etiquette and regular hand washing.
- If ventilation is poor in the office, Dr. Solante urges the management to consult with engineers on how to improve air flow.
In Public Transport
- Always wear a face mask and face shield. Make sure your eyes, nose and mouth are covered.
- Try not to open your mouth. This means avoiding activities such as eating, conversing and talking on cellphones.
- Maintain physical distancing. Passengers should at least be a seat apart.
In a nutshell, Dr. Solante gives these 5 important tips during the pandemic:
- Practice regular hand washing.
- Wear your face mask and face shield.
- Maintain a physical distance of six feet or more.
- Avoid crowded areas.
- Only visit places with good ventilation.
Though the airborne transmission is cause for alarm, following health protocols is still an effective countermeasure. Complying to guidelines set by health experts and being vaccinated are still your best bets in safeguarding your health and that of other people.
*interview by Trisha Garin