But aren't most common illnesses (e.g. cold and flu) from viruses, not bacteria? I wouldn't expect this sort of culture to show the kind of stuff that causes mo

But aren't most common illnesses (e.g. cold and flu) from viruses, not bacteria? I wouldn't expect this sort of culture to show the kind of stuff that causes most people to get sick, even if it is spread by things like keyboards or mice or door handles.