239 Scientists Show COVID-19 Airborne Transmission Risk Possible
Tue, April 20, 2021

239 Scientists Show COVID-19 Airborne Transmission Risk Possible

 

The difficulty in controlling the spread of the coronavirus disease motivated experts around the world to dig deeper into its transmission risk. Recently, more than 200 scientists urged the World Health Organization to change its guidelines about the disease. They found that COVID-19 could be transmitted through the air, an indicator of being airborne.

The airborne transmission risk of COVID-19 was revealed by 239 scientists. They called for the World Health Organization (WHO) of the United Nations to modify the guidelines for the disease. Their findings showed that airborne transmission is possible if the liquid droplets are incredibly tiny. These droplets could last in the air longer and risk people contracting the SARS-CoV-2 virus. The letter sent to WHO has been published in the journal Clinical Infectious Diseases.

The Current Guidelines of the WHO on COVID-19

After COVID-19 infected hundreds of thousands of people worldwide, health organizations have posted the most common, less common, and serious symptoms of the disease. The WHO is one of these organizations that revealed what people may experience if they catch the illness. However, all of these entities do not claim that an infected person may always be symptomatic. Some may feel nothing and unknowingly recovered from the illness.

For the transmission risk, the guidelines of the WHO show that the primary transmission mode of SARS-CoV-2 is via respiratory droplets, expelled by people who are coughing or sneezing. The same droplets may be emitted as well by speaking. Despite being small, the droplets are relatively heavier than air and unlikely to travel far from where they were expelled. But once the droplets sink to the ground, any object or surface touched may be contaminated with the virus or other pathogens. Objects and surfaces contaminated with pathogens are turned into fomites, inanimate objects that transmit communicable diseases.

Because the transmission mode is through respiratory droplets, everyone is advised to wear face masks or even face shields to protect themselves, especially in public. The protection level is likely to increase if people will maintain a distance of one meter, at least, from each other. The public is also advised not to touch any part of their face to prevent contracting the disease if they touched an object or surface. So, proper handwashing and good hygiene play a role in avoiding COVID-19.

While that transmission mode is supported by solid evidence, the WHO is not entirely sure if the disease is airborne, which means the organization has yet to obtain solid proof that it can be spread through the air. If the WHO declares COVID-19 as airborne, people may think that the transmission risk is similar to measles – one of the most contagious diseases in human history with an infection rate of nine out of ten people, who are not immune.

 

 

Airborne Potential of COVID-19 Unveiled by Scientists

A team of 239 scientists across the globe submitted a letter to the WHO to show evidence of airborne transmission risk in COVID-19. The letter urged the organization to change its guidelines as soon as possible to better aid the global healthcare system and governments in containing the disease. If the virus could be spread through the air, certain settings must be highlighted to protect more people from COVID-19.

"This is one in a series of many miscues. It's really unfortunate how the WHO has led to all sorts of confusion," said Dr. Eric Topol, director and founder of the Scripps Research Translational Institute, as quoted by Time, an American news magazine.

The WHO already received the letter and said that they are still gathering evidence. But they do not ignore the possibility of airborne transmission risk. Since earlier studies determined aerosolization as a major means for the virus to spread, they acknowledge the potential of airborne. Though, the tug of war between WHO and public health will persist until the guidelines are changed.

In the letter, scientists highlighted the difference between the respiratory droplet and airborne transmission risks. The first one refers to droplets suspended in the air with a size of five micrometers or larger. A distance of one to two meters from the source of the droplets can help avoid them. Eventually, these droplets will fall to the ground due to their size. The second one refers to droplets with a size of fewer than five micrometers.

Due to the relative weight, the smaller droplets may suspend longer in the air and the general rule in social distancing may not work. If air velocity is added, the smaller droplets will move through the air without a hitch. This enables the droplets to travel several meters away from the source, which can explain the spatial pattern of infections in retrospective studies. Even with social distancing, the infections may still occur indoors.

 

 

Although the findings may induce panic and worry among the public, the changes are not substantial if simplified. With airborne transmission risk added, ventilation becomes a crucial factor in controlling the spread of COVID-19. Well-ventilated rooms - with windows open and fans turned on - have a higher chance of pushing microbes, whether viruses or not, outside. This is because the air is flowing constantly, preventing it from going stagnant and causing the spread of contagious illnesses.

That particular change in the guidelines must include specifics as well for ventilation of rooms and other spaces. For example, supplementary effects on normal ventilation may help decrease the spread of illnesses. Supplements like germicidal ultraviolet lights and high-efficiency air filtration may aid in limiting airborne transmission risk. These supplements are highly recommended in spaces dependent on air-conditioning.

And finally, avoid overcrowding in any setting involving enclosed spaces. Even though it is going to be difficult in most cities, the letter suggests discouraging crowds inside buildings and public transportation.

In the July 7, 2020 report of the WHO, a total of 172,512 new cases and 3,419 new deaths were reported in the last 24 hours. Those numbers brought the total global confirmed cases at 11,500,302 and confirmed deaths at 535,759. The Region of the Americas remained with the highest confirmed cases and deaths at 5,915,551 and 266,736, respectively. While the Western Pacific Region had the lowest confirmed cases at 229,590, and Africa with the lowest confirmed deaths at 7,139.

Whether or not COVID-19 is airborne, people should realize that the current preventive measures are already designed to fight the transmission risk. The real concern is in enclosed spaces or rooms with limited ventilation. The air tends to cycle in the same area without being refreshed if no technologies are installed. In such a scenario, an N95 respirator may be the ultimate defense to filter out dirty air.