The US Centers for Disease Control and Prevention has again updated its guidance about how Covid-19 spreads to include information about potential for airborne transmission.
"CDC continues to believe, based on current science, that people are more likely to become infected the longer and closer they are to a person with COVID-19," the agency said in a statement on Monday.
"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.