The CDC's current guidance still suggests that the most common way to become infected with the coronavirus is direct contact with a carrier who is less than six feet away from you.
The novel coronavirus can spread through the air to people who are more than 6 feet away from an infectious person, the U.S. Centers for Disease Control and Prevention said on Monday, in guidance that could raise new challenges for safely re-opening businesses and schools. "I would like to emphasize that short-range airborne transmission when people are in close contact, meaning inhalation of aerosols, probably is more important than transmission by large droplets that are sprayed onto mucous membranes". CDC's new guidance, updated October 5, also notes that COVID-19 spreads easily, by close contact with respiratory droplets comprised of large and small droplets as well as smaller particle-sized droplets.
Evidence shows the risk of "airborne transmission" - as opposed to "droplet transmission" - is higher when an infected person breathes heavily, "for example while singing or exercising", while in an "enclosed space" with "inadequate ventilation".
"Today, CDC issued updated guidance to its How COVID-19 Spreads website, which includes information about the potential for airborne spread of the virus that causes COVID-19", the CDC explained on their website. This is specifically true for enclosed spaces without adequate ventilation. "The people who were infected were in the same space during the same time or shortly after the person with COVID-19 had left", the CDC explained. Such droplets typically infect people while in close proximity to infected people, said the CDC.
The alarming statistic came from the head of WHO's Health Emergencies Program, Dr Michael Ryan, who, while speaking to the 34-member executive board, said that "according to their best estimates, roughly 10 percent of the world's population might have been infected by the virus".
They said: "At this time, there is no indication of a general community need to use special engineering controls, such as those required to protect against airborne transmission of infections, like measles or tuberculosis, in the healthcare setting".
The change comes after a heated debate between public health experts and USA authorities over the risk of airborne transmission and Covid-19. In response, the health agency did acknowledge that there was some evidence of airborne transmission in certain environments. This is why the CDC recommends the wearing of face masks when social distancing can't be observed.