The novel coronavirus can spread through the air to people who are more than 6 feet away from an infectious person, the US Centers for Disease Control and Prevention said on Monday.
In an update in its website, the CDC said the coronavirus can sometimes be spread through small particles that can linger in the air and infect people separated by distances previously considered safe. Many social-distancing guidelines adopted by workplaces, restaurants and stores advise people to stand at least 6 feet (1.8 meters) apart to avoid transmitting the pathogen that causes Covid-19.
But this change in guidance could raise new challenges for safely re-opening businesses and schools.
“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,” the agency said in a news release.
The change follows months of mounting scientific evidence that Sars-CoV-2 can be transmitted through the air at greater distances than understood in earlier stages of the pandemic. There have been indications the CDC was moving toward updating its guidance. Last month, it posted and then removed a guideline on airborne transmission, later describing it as a draft posted in error.
The CDC’s updated site includes a section acknowledging that virus particles also sometimes spread through the air, particularly in enclosed spaces with poor ventilation. Scientists believe that in these cases, airborne virus particles emitted “became concentrated enough to spread the virus to other people,” including sometimes shortly after the infectious person left.