"Definition of epidemic
1 : affecting or tending to affect a disproportionately large number of individuals within a population, community, or region at the same time"
https://www.merriam-webster.com/dictionary/epidemic
Sounds like @deirdyweirdy is using the word correctly in this context.
that would also include natural disasters like hurricanes and political elections..
I see your point.
We should let Merriam Webster know.