COVID-19, caused by SARS-CoV-2 (a novel coronavirus), is now believed to spread through airborne transmission.
After the much-discussed study released by The Lancet on the airborne transmission of COVID-19, WHO (World Health Organization) and CDC (USA) (Centers For Diseases Control and Prevention) have recently updated their take on the same.
The Lancet is an independent international general medical journal that was founded in 1823. A group of 6 scientists from the US, UK and Canada had cited enough reasons for why SARS-CoV-2 is transmitted primarily by the airborne route in their study published in The Lancet in early March 2021.
The newest updates of WHO and CDC (USA) clearly state that the infection is now spreading through smaller or aerosolized particles, re-emphasizing and confirming the findings of “The Lancet Study”.
Previous Update: How is SARS-CoV-2 Transmitted?
According to our previous understanding, the primary mode of transmission of SARS-CoV-2 was through infected respiratory fluids.
These respiratory fluids were released during exhalation (e.g., quiet breathing, speaking, singing, exercise, coughing, sneezing, etc.) in the form of droplets which were of various sizes. It was the droplets that carried the virus and transmitted the infection.
The larger droplets, produced while sneezing or coughing, usually dropped quickly due to gravity within about two meters of the source.
The smaller or very fine droplets, called aerosol particles, were constantly being produced (even with breathing), but increased with normal activities like talking, singing or coughing. They floated in the air like smoke and could remain suspended for a longer time, from several minutes to hours. This helped such particles to concentrate easily even in indoor settings.
This spread increased the number of confirmed COVID-19 cases.
Latest Updates: How is SARS-CoV-2 Transmitted?
According to the latest updates of WHO and CDC (as of May 2021), COVID-19 spreads in three principal ways:
1. Inhalation/airborne transmission of air carrying very small or fine droplets (aerosol particles) that contain the infectious virus.
The risk of transmission is greatest within three to 6 feet of an infectious source where the concentration of these very fine particles is greatest.
2. Deposition of virus present in exhaled droplets and particles onto exposed mucous membranes of healthy individuals (i.e., particles that contain virus land on the eyes, nose, or mouth, especially through ‘splashes and sprays’ like a cough or sneeze).
The risk of transmission is the greatest close to an infectious source where the concentration of these exhaled droplets and particles is greatest.
3. Touching exposed mucous membranes (eyes, nose, or mouth) with hands that contain infected respiratory fluids or from touching surfaces contaminated with the virus.
The risk and severity of the COVID-19 infection vary according to the individual’s exposure to the virus particles.
Airborne Transmission Can Infect Individuals 6 Feet From an Infectious Source
Although the infection is less likely to spread rapidly due to inhalation at distances more than 6 feet from the source of infection, given the airborne mode of transmission, it is not impossible.
Studies report that if an infectious person exhales the virus indoors for more than 15 minutes or a few hours, it can lead to virus concentrations in the air space, which is enough to transmit infections to people beyond a distance of 6 feet.
As per experts, some of the factors that can increase the risk of SARS-CoV-2 infection are:
Closed spaces with inadequate ventilation or enclosed spaces without air filters.
Increased exhalation of respiratory fluids when the infectious person exercises, shouts or sings.
Prolonged exposure to these conditions, typically for more than 15 minutes.
How to Protect Yourself And Others
The best way to avoid contracting the infection is by following all set guidelines and protocols.
Protect yourself and others by:
Getting yourself vaccinated for COVID-19 as soon as possible.
Double masking: Wearing a surgical mask under a proper, snug-fitting face mask (cloth mask) that covers your nose and mouth.
Maintaining at least 6 feet distance from others, at home and outdoors.
Avoiding crowded and poorly ventilated indoor spaces.
Improving ventilation (by keeping doors and windows open) and using air filters or purifiers.
Washing your hands frequently, for at least 40 seconds with soap and water.
Stay home, stay safe and get vaccinated!
References:
1. Who. int. 2021. Modes of transmission of virus causing COVID-19: implications for IPC precaution recommendations. [online] Available at: <https://www.who.int/news-room/commentaries/detail/modes-of-transmission-of-virus-causing-covid-19-implications-for-ipc-precaution-recommendations> [Accessed 12 May 2021].
2. Centers for Disease Control and Prevention. 2021. Coronavirus Disease 2019 (COVID-19). [online] Available at: <https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/sars-cov-2-transmission.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fscience%2Fscience-briefs%2Fscientific-brief-sars-cov-2.html> [Accessed 12 May 2021].
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