The ongoing COVID-19 pandemic now has over three million confirmed cases around the globe and has continued to spread particularly in Eastern European and South Asian countries. In addition, there is also a risk of a second wave in the countries that have managed to control cases of the coronavirus infection.
This has led to an increased focus on the modes of transmission of the SARS-CoV-2 as it is a mandatory factor in controlling the current health crisis. Till now, research has established that the virus primarily spreads through aerosol particles in the air that are released through coughing and sneezing by an infected person.
Secondly, a number of studies have also suggested that breathing and talking by asymptomatic people may also contribute to the spread of COVID-19. Therefore, investigating further in order to provide instructions on avoiding the infection by possible protective measures is important.
A new study, which is titled “Consideration of the Aerosol Transmission for COVID-19 and Public Health,” not only shows how the virus is able to spread from one person to another through aerosol particles but also provides a number of guidelines on protection for prevention.
According to the findings of the study, which appear in the journal Risk Analysis, the primary focus of the COVID-19 research has been the transmission of SARS-CoV-2 via first-hand contact with an infected person in a hospital setting during treatment.
The second most concerning mode of transmission after exposure at hospitals has been hand to face contact after touching a surface that has been infected with COVID-19. Although aerosol particles can play an equally important role in transmission, they are not as highlighted.
Aerosols are small particles that can remain in the air for a considerable amount of time and have the ability of long-range transport many times as well.
At the beginning of April, a report by the National Academy of Sciences Committee on Twenty-first-century health threats and Emerging Infectious Diseases stated that although there is limited research on COVID-19 and SARS-CoV-2, it is confirmed that the virus can spread easily via aerosol particles.
More specifically, the report stated that “the results of available studies are consistent with aerosolization of virus from normal breathing.”
Research on asymptomatic cases of the coronavirus infection showed that SARS-CoV-2 is able to transmit through normal activities including talking or even breathing. This is because these activities also produce small droplets that can aid in spreading the virus.
Therefore, even if a person displays no conventional signs of COVID-19 such as sneezing and coughing, the virus can still transmit to another person.
Read more on the airborne transmission of viruses here.
In addition, the aerosol particles produced by breathing or talking are so tiny in size that they are capable of staying in the air for a very long time before settling on the ground. This means that they can also cover a long distance while they are still in the air.
A study from 2006 on the SARS-CoV-1 virus showed that the particles’ time duration in the air varies in accordance with their size. For instance, particles with a diameter of 1-3 μm can stay in the air for a very long period of time in comparison with those with a 20 μm diameter which settled in three minutes.
The authors of the new study suggest further research and investigation on transport distance and survival duration of SARS-CoV-2 in different temperatures, humidity levels, and environments.
Secondly, there should also be a focus on ‘aerosol contamination’ of surfaces, rooms, houses, and buildings in order to establish methods of decontamination to control the spread of COVID-19.