The Centers for Disease Control and Prevention (CDC) said on Monday that the coronavirus can spread through airborne transmission, a long-anticipated update to the agency’s website.
There is evidence that under certain conditions, people with COVID-19 seem to have infected others who were more than 6 feet away,” the CDC website says. “These transmissions occurred within enclosed spaces that had inadequate ventilation. Sometimes the infected person was breathing heavily, for example while singing or exercising.
Under these circumstances, scientists believe that the amount of infectious smaller droplet and particles produced by the people with COVID-19 became concentrated enough to spread the virus to other people. 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 new guidance comes after an incident last month when the agency removed a draft document posted online about airborne transmission that was still under review.
The previous language, officials said at the time, could be misinterpreted as suggesting that airborne transmission is the most common way of spreading the virus.
In fact, scientists believe the most common method of transmission is through larger respiratory droplets dispersed when someone sneezes, coughs, talks or sings.
“Today’s update acknowledges the existence of some published reports showing limited, uncommon circumstances where people with COVID-19 infected others who were more than 6 feet away or shortly after the COVID-19-positive person left an area. In these instances, transmission occurred in poorly ventilated and enclosed spaces that often involved activities that caused heavier breathing, like singing or exercise. Such environments and activities may contribute to the buildup of virus-carrying particles.”
Last month, the agency updated its guidance to say Covid-19 could spread through the air, then abruptly reverted to its previous guidance days later. At the time, the agency said a draft version of proposed changes had been posted in error, and once the scientific review process was completed, the new language would be posted.
CDC says people can protect themselves from the coronavirus by staying 6 feet away from others, wearing a mask that covers their nose and mouth, washing hands frequently, cleaning surfaces and staying home when sick.