The US Centers for Disease Control and Prevention abruptly dropped new guidance from its website about airborne transmission of the coronavirus yesterday, just days after publishing it.
The agency said a draft version was posted in error, before it had gone through the normal review process, and reverted to its previous guidance, which does not mention airborne transmission.
The back and forth by America's top health authority is confusing and worrying. Scientists have been calling for the risk of airborne transmission to be recognized by health authorities.
Evidence shows the virus is primarily spread through droplets that come out of people's mouths and noses. Large droplets fall onto surfaces rapidly and can be picked up on fingers and carried to the eyes, nose or mouth. That's why it's important people don't touch their faces and wash their hands regularly.
But there is now more evidence that smaller-sized droplets can remain in the air in the form of aerosol particles which can be inhaled. Several international health authorities have already acknowledged this way of transmission, stressing the need to wear masks.
A federal official familiar with the situation told CNN the guidance is "getting revised," but didn't say when the update would be posted to the CDC website.
Researchers and doctors said they were glad to see CDC was expected to acknowledge airborne transmission, but some worried the back and forth could cause more confusion about how the virus spreads and what measures will reduce the risk.
A version of this story appeared in the September 22 edition of CNN's Coronavirus: Fact vs. Fiction newsletter. Sign up here to receive the need-to-know headlines every weekday.
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