It's not a real big deal if you treat it early enough.
Seems the Plague came into the US from China around 1900 in San Francisco but was covered up and never publicized.
Given how disgusting and unsanitary our rat infested our cities are becoming and how "homeless" drug addled people live in very close proximity to these rats it would not take much to start another mini pandemic and San Francisco or LA would be the perfect place for it to start.
I’m actually surprised there hasn’t been a plague outbreak yet.