I live in a rural place in the middle of the USA, but we have a large number of international travelers pass through. I am aware of several local cases that seem very COVID-like that predate January 2020. Two of these I knew about before anyone heard of the outbreak in Hubei. I remember discussing at the time how it was weird to hear of someone in their early 50s to be hospitalized with pneumonia from 'flu'. Anyway I wonder if you have heard any similar reports and your thoughts on the potential for much earlier transmission in the US.

Honestly it's really really hard to say for sure.

It's not super likely, because we don't have the epidemiological data (increased deaths from non-influenza pneumonia at a large scale) to support that, to my knowledge.

It's certainly possible. And it is true that our methods of detection of viruses are ill-equipped so you can assume we're almost always behind the curve a bit.

But there also isn't much more than anecdote to support this. Lots of people get influenza-based pneumonia in the winter. Could you consider the possibility that your recollection is now tainted? And that you are primed to notice those events more? It was also already a very bad flu season. See here:

-https://time.com/5758953/flu-season-2019-2020/

-https://www.medscape.com/viewarticle/924728

Another kind of issue is that early reports of "SARS-2 positive serum!" were overblown, which colored a lot of news reports on this. They basically made the tests too "promiscuous" so they also detected antibodies against common cold coronaviruses. That was a big problem. If you're curious about how tests like this work, you can check out this other post I wrote on that! Antibody tests are actually my specialty!

https://www.reddit.com/r/medicine/comments/g1ty3g/are_immuni...