The coronavirus might be spread by seemingly healthy people even more easily than previously thought.
It's been clear that asymptomatic people can spread the virus by coughing or sneezing, but researchers are now pretty sure that even talking can spread the virus that causes COVID-19, reported The Daily Beast.
“The act of speaking generates oral fluid droplets that vary widely in size, and these droplets can harbor infectious virus particles,” wrote a team of researchers in a study published in The New England Journal of Medicine.
The researchers -- from the National Institutes of Health in Bethesda, Maryland, and Christina Bax at the University of Pennsylvania -- found that aerosolized spittle particles were small enough to be carried by air currents and dispersed.
“It remains an open question how important this is in COVID-19 transmission,” said Keith Jerome, director of the University of Washington Virology Lab. “Does this explain why there’s such easy spread, or is it just a minor contributor?”
The study found that speaking loudly produced as many as 347 measurable droplets in a single frame of a video, while a loud whisper cut that number down to 227 -- but each of those droplets could still transport pathogens.
Researchers aren't certain how efficiently the virus could be spread just by speaking, as compared to coughing or sneezing, but they are fairly confident that masks would help block that transmission.
"The advisability of wearing a suitable mask whenever it is thought that infected persons may be nearby and of providing adequate ventilation of enclosed spaces where such persons are known to be or may recently have been,” wrote Harvard molecular biologist Matthew Meselson in a letter to The New England Journal of Medicine.
But not just any mask will do, researchers say.
“There is a need to develop better protection against infectious agents in air, and that need is all the more acute when vaccines are either not available or are limited in their effectiveness,” said Herek Clack, a University of Michigan engineer currently developing new medical masks.