The greatest shortcoming of the human race is our inability to understand the exponential function.
(Prof. Al Bartlett)
Matters of exponential growth are barely understood by the public. An epidemic progresses by the natural growth laws that include the exponential function. Small numbers in the beginning may indicate a false security but can rise rather quickly to uncontrollable conditions. This almost every time causes a too late response. See the best youtube video about exponential growth and extend your mind.
The current crisis we face is a result of too late response by hoping we can wait. During a fast exponential growth process with doubling times of 2-4 days, time is rather short and no day to act should be lost. Because by right action, a small change in number in the beginning with make a huge difference at the end!
A very good introduction is the youtube-video below, that I truely recommend. Even experts might find some interesting new aspects. For politicians it should be a must!