US CDC acknowledges Covid-19 virus is airborne

NEW DELHI: The US Centers for Disease Control and Prevention (CDC) has acknowledged that the SARS-CoV-2 virus, behind the Covid-19 pandemic, is airborne and can be transmitted through very fine aerosolised particles released during respiration.

The CDC updated its public guidelines on Friday where it mentioned that SARS-CoV-2 is transmitted by exposure to infectious respiratory fluids. The agency said that while talking, people release respiratory fluids which then settle on nearby surfaces or can remain suspended in the air.

While the larger droplets settle out of the air rapidly within seconds to minutes, the very fine droplets and aerosol particles can remain suspended in the air for minutes to hours.

The agency noted that although infections through inhalation at distances greater than six feet from an infectious source are less likely, an infectious person exhaling virus indoors for an extended time (more than 15 minutes and in some cases hours) can lead to concentration of the virus in the air, which may then infect people even if they are six feet away.

The CDC’s guidelines update comes nearly a month after a paper was published in The Lancet journal claiming that the SARS-CoV-2 virus is predominantly transmitted through the air. The analysis by six experts from the UK, the US and Canada said public health measures that fail to treat the virus as predominantly airborne leave people unprotected and allow the virus to spread.

Since the breakout of the virus on the global stage, several scientists have been appealing to the medical community and to the relevant national and international bodies to recognise the potential for airborne spread of Covid-19.

After initial denial, the World Health Organisation had in July 2020 agreed that the possibility of novel coronavirus remaining in the air in crowded indoor spaces, where “short-range aerosol transmission… cannot be ruled out”.

The WHO had said that some outbreaks that have occurred in crowded indoor spaces suggest “the possibility of aerosol transmission”, although “combined with droplet transmission”. Such situations have arisen “during choir practice, in restaurants or in fitness classes”.

According to the WHO, “in these events, short-range aerosol transmission, particularly in specific indoor locations, such as crowded and inadequately ventilated spaces over a prolonged period of time with infected persons cannot be ruled out”.