contagious diseases

What's behind the "14 days of self-quarantine" guidance after exposure to someone with COVID-19 or after travel from a place with a high number of cases? Think of yourself as a potential incubator.

Finally getting out from under the flu? Just because you're feeling better doesn't mean you can't get other people sick. You can spread the flu for longer than you might think.

Ten thousand years ago, many of our deadly human diseases didn't exist. What happened?