By the time you have a significant number of cases, it's too late. One of the troubling things about Covid-19 is that you become contagious before you show symptoms, and a lot of people don't ever show symptoms at all. If there are two confirmed positive tests, it's a pretty good bet that there are a bunch more local cases that have not yet been identified.
Yes, it seems like on average it takes Five days for you to show symptoms. So think of where we are at, imagine an exponential increase in five days, and this is where we will be. Which is scary. Mass had 100 percent increase in cases in one day. People have to insist to their employers they will work from home. If you can’t work from home be strapped with a lot of hand sanitizer and wear a mask. I have seen some wearing masks here in the last day. I think within one week all will wear gloves and masks in public.