This seems pretty significant. https://twitter.com/latimes/status/1252817269740072963

First, it means that COVID-19 was likely circulating in CA as early as mid-January (and suggests that it was circulating even earlier than that).

Secondly, it means that death counts are likely under-reported (which most analyses have been taking as pretty much accurate, even if case counts are essentially meaningless, given the lack of randomized testing).

I wouldn't interpret the above statements as 'this thing is way more dangerous than we realized', but rather say it means 'wow, this things is dangerous, but we have significant doubts about both the numerator (death count) and denominator (case count) for determining lethality'

CA should start doing randomized antibody testing in affected areas (which it seems is already starting) https://twitter.com/i/events/1252744940762722304

I think that something more like wastewater testing would scale much better given the current bottlenecks in testing. https://www.statnews.com/2020/04/07/new-research-wastewater-community-spread-covid-19/

“This wasn’t recognized because we were having a severe flu season,”

Was it a severe flu season? or an early COVID season?

Seems like one item we should add to our collective retro on COVID-19 is that we should be regularly taking genetic tests on relatively common viruses like the flu and common cold to determine if that's really what's going on.