When you are sick you stay away from people, right? Even without the CDC, our government officials, Prime Ministers, etc. telling us what to do we all have common sense. So why is it spreading so fast and extensively?
Simple: it combines fast spreading between humans with slow expansion inside humans!
The graph below shows the number of days from being infected to showing symptoms; fever, cough, aches and pains, etc. The data is from the CDC and a journal publication yesterday concerning the cruise ship infection.
The virus spreads fast, in human terms, because the virus infects quickly and easily but then expands slowly, in virus terms. This makes it slow to trigger the bodies defenses. And it is our RESPONSE to the virus, not the virus itself, that we recognize as feeling sick.
As a consequence, one of every two infected people spend almost ONE week with no symptoms. During that week they can spread the virus. From the conveyance outbreak on the cruise ship, almost one in five NEVER show symptoms.
So if you are sick, stay home and if you are not sick, stay home. Even if you aren’t sick that very moment, social distancing is still the right thing to do.