If cold (flu) cases were mapped geographically over time, would you see the disease move in continuous waves or pop up in locations sporadically?

Question

If cold (flu) cases were mapped geographically over time, would you see the disease move in continuous waves or pop up in locations sporadically?

In: Mathematics

Answer 1

[As it happens, the CDC has a map of that!](https://www.cdc.gov/flu/weekly/usmap.htm) You can watch it both rise and fall in swaths across the country.

*Edit:* [Here’s a similar map for Europe.](http://flunewseurope.org/)

*Edit:* Thanks to /u/d_lowl for [this worldwide map](https://nextstrain.org/flu/seasonal) (scroll down).