New Delhi: The Centers for Disease Control and Prevention (CDC) has updated its public policy on the transmission of SARS-CoV-2, the virus that causes coronavirus (COVID-19).
As of May 7, 2021, there were three major updates from CDC that said that the transmission of SARS-CoV-2 could be prevented by inhalation of virus in the air more than six meters from an infectious source, SARS-CoV -2 is transmitted by exposure to infected respiratory fluids and that the risk of SARS-CoV-2 infection varies according to the number of viruses to which a person is exposed.
Transmission of COVID-19 virus inhalation virus:
According to CDC, with increasing distance from the infectious source, the role of inhalation also increases. “Although infections by inhalation at distances greater than six meters from an infectious source are less likely than at closer distances, the phenomenon has been repeatedly documented under certain prevalent conditions,” the Scientific Letter reads.
It stated that these transmission events involved the presence of an infected person who had been inhaling the virus for a long time (more than 15 minutes and in some cases hours), leading to virus concentrations in the airspace sufficient to transmit infections to people more than 6 feet away. While in some cases it can transmit infections to people passing through this space shortly after the infected person is gone.
According to CDC, the factors that increase the risk of SARS-CoV-2 infection under these conditions are:
Enclosed spaces with inadequate ventilation or air handling whereby the concentration of exhaled respiratory fluids, especially very fine droplets and aerosol particles, can build up in the air space.
2. Increased exhalation of respiratory fluid when the infected person is engaged in physical exertion or raises their voice (e.g., practice, shout, sing).
Prolonged exposure to these conditions, typically more than 15 minutes.
Transmission of COVID-19 by exposure to infected respiratory fluids
The CDC said the main mode in which people become infected with COVID-19 is through exposure to respiratory fluids that carry the infectious virus.
They stated that exposure occurs in three main ways:
Inhalation of very fine respiratory drops and aerosol particles.
Deposition of respiratory droplets and particles on exposed mucous membranes in the mouth, nose or eye by direct splashes and syringes.
Contact of mucous membranes with hands that are directly contaminated by virus-containing respiratory fluids or indirectly by contact with surfaces with the virus on them.
Earlier on April 16, Lancet magazine said there was strong evidence to suggest that the SARS-CoV-2 virus is primarily transmitted through the air. The report stated that public health measures that do not treat the virus as generally in the air, leave people unprotected and allow the virus to spread.