For travel, the US Center For Disease Control (CDC) has advisory levels:
https://wwwnc.cdc.gov/travel/notices
Level 3 is “avoid unnecessary travel”.
Level 2: “Practice Enganced Precautions” (this would mean avoiding large crowds; Japan is currently level 2).
Level 3 is “practice usual precautions”. I think this means “wash your hands, you slob”.
The reaction to this virus is so hyper because as a world community, we have not yet developed the regular tools for treating. We are still gaining knowledge. For example, many have wondered why relatively young Chinese doctors are dying from it. One theory is that it is much more lethal on your second round, and the doctors and nurses treating it get multiple cases. Hyper attention is justified until this is all sorted out.