Certainly seems there had to be sporadic cases around the country since late January.

It was in Europe by then and almost every early March documented case in the USA was traced directly to European travel. Makes sense that a lot were missed especially since almost no testing was happening at that point.

However, I don't think there were really widespread infections here before early March. It just doesn't fit with much else we know:

1. Currently, re-opening less affected areas without much travel does not seem to be leading to explosions of new cases. On the other hand, new cases in heavily affected areas are not falling quite as quickly as expected, even with shutdowns.

2. There are just too many instances where a single carrier led to large outbreaks (Albany Ga, New Rochelle NY, concert in Brooklyn to name a few). Just from personal experience, I know that a factory in central/south Alabama is having a nightmarish time keeping their operations open because no matter what steps they have taken so far --short of now attempting to close completely for some days and testing every single employee coming back in-- has stopped it from spreading through the workforce.

So many things like these support the idea that it spreads quite easily and is hard to stop once it has spread through enough people in a community. Yet, shutting down travel between heavily infected areas and other parts of the country seems to have kept cases low enough that re-opening without lots of travel isn't causing explosions.

3. Overall death rates over 20% higher than normal in affected areas beginning in later March also seems to suggest that any widespread infections as early as January would have resulted in those death rates soaring much sooner.

None of that means there were no cases back in January but would suggest that they were very sporadic and not much wide community spread was happening until, at earliest, very late February.

This post was edited on 5/19/20 at 12:43 am