This is because “infectious aerosols,” or tiny droplets containing active virus, can hang out in the air after being exhaled. So even if you avoid public sneezers and coughers like the plague, you may still catch the flu virus just by being in the vicinity of someone who has it. Samples of their exhalations during these activities were collected and analyzed to detect flu, both active virus and pieces of RNA that are merely detectable. In fact, about a third of the fine aerosol samples collected during breathing had active virus in them, which the researchers say indicates that coughing or sneezing is not necessary to spread the flu. “We found that flu cases contaminated the air around them with infectious virus just by breathing, without coughing or sneezing,” said study author Donald Milton in a statement.

Source: Forbes January 26, 2018 18:22 UTC