I really want this to be true -- I had that vicious bronchitis in January -- but I really doubt it.

I also don't want it to be true, because I don't want to have been a spreader. https://twitter.com/chrismattmann/status/1249367188936331268

As I've said before, I think it's much more likely that there was a separate bronchitis going around pretty widely -- not the flu, symptoms didn't match, maybe *a* coronavirus but not COVID-19.

Anecdata, but a lot of people in my extended/global social network seemed to catch it back in December or earlier. If it were COVID-19, that would be reflected in both the overall mortality statistics (earlier spike) and the phylogenetic tree.

The phylogenetic tree in particular carries a lot of information. eg: the Seattle flu study was (IIRC) able to infer a single point of introduction sometime in January. By the end of February, that had only grown to something like 100-1000 cases (again inferred).

To rephrase all of this in a more concise way:

Sure, it might have been introduced back in December or even November. Your chance of having had it back then would still be essentially zero. That's how exponential growth works. Long fuse before the boom.

This thread answers most of the questions raised, go read this one and forget what I said. https://twitter.com/trvrb/status/1249414291297464321?s=21