Post #1226: COVID-19 trend to 8/27/2021, finishing out the week, and a note on COVID-19 death rate

 

As pictured here, we’re still on track for a peak of the Delta wave in early September.

The U.S. is now at 48 new COVID-19 cases per 100,000 population per day, down a bit from yesterday.  The seven-day increase was 7%, not materially different from yesterday.

As we saw in past waves, a second “wavelet” of states is emerging.  New case rates have peaked in the three states that led the wave (FL, LA, MS).  Those states are now being overtaken by KY, SC, and TN, all of which have current new case counts in the 90s and double-digit growth rates.  Georgia and Alabama are not far behind.

Continue reading Post #1226: COVID-19 trend to 8/27/2021, finishing out the week, and a note on COVID-19 death rate

Post #1224: Virginia data on breakthrough infections.

 

Virginia is very much a middle-of-the-road state.  We’ve had reasonable and sensible guidance from our governor (who is himself an MD) throughout the pandemic.  The Commonwealth made disaster preparations early on, converting a dorm at one of the big state schools into a standby hospital facility.  And we always seem to be in the middle of the pack in terms of infection rate, vaccination rate, mask use, and so on.

Not coincidentally, the Commonwealth of Virginia has consistently produced (IMHO) the best publicly-available data on the COVID-19 pandemic.  In particular, they recently began summarizing “breakthrough” infections, that is, COVID-19 infections among vaccinated individuals. Continue reading Post #1224: Virginia data on breakthrough infections.

Post #1222: Looking beyond the peak of the U.S. fifth (Delta) wave.

 

In this post, we pry our eyes off the peak of the Delta wave — off the train wrecks occurring in Florida, Louisiana, and Mississippi — and purposefully look elsewhere.  There are two main questions:  Which states are the rising hotspots, and when/where should we expect the U.S. winter wave?

 

Part 1:  Rising hotspots.

It’s not obvious how to define this category.  I’m putting FL, LA, MS aside.  What I’m looking for is the next set of states that will stress out their hospital systems over a large geographic area.   That seems to occur pretty consistently when new cases per 100K per day exceeds a value of about 100.

Accordingly, a state might be on the watch list either because they have a high level of cases now, or because they have a more modest level of cases, but a high current growth rate.

For this exercise, I’ve tagged all the states that I would project to exceed that 100 / 100K / day mark within the next two weeks, if they maintain their current seven-day rate of increase.  In short, these are the states where you’d expect a hospital crisis in the next couple of weeks if they stick to their current trend.

Data source for these and other graphs of new case counts:  Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 8/25/2021, from https://github.com/nytimes/covid-19-data.”  The NY Times U.S. tracking page may be found at https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html.

Map (below) courtesy of Mapchart.net

 

Not terribly interesting in and of itself.  It’s an arbitrary cutoff, and and arbitary projection.  Let me pull those apart a bit.

The cluster at the bottom right of the map is clearly just an extension of the current wave.  A few more Gulf states, a few more South/South-Central states. I would characterize that as “no surprises there”.

Geographically, the oddity here seems to be the adjacent states of Wyoming and South Dakota. (Throughout the pandemic, Alaska has largely taken its own independent course.)

 

The oddity is reinforced by the complete absence of a summer 2020 wave in those states.  If I stick with the story that “the Delta wave is just the 2020 summer wave, but worse”, those two states break the rules.

A second oddity is that both South Dakota and Wyoming were leaders in the U.S. 2020 winter wave.  Now, I know what you’re thinking.  It’s not winter yet.  Today it’s going to in the 90’s F here in Virginia.  It’s way to soon to be thinking about the winter wave.

But just look back to last year, see when those two states began their rise for the 2020 winter wave.  It was, in fact, end-of-August, early-September.  Those are the callouts on the chart above.

Not quite sure what to make of that, but it’s interesting enough to flag it.  Three states break my “Delta is last year’s summer wave” rule.  Two are geographically isolated from the rest, but are next door neighbors.  Those were two of the three states (along with ND) that led the winter wave.  And they started their upturn for the winter wave right about this time last year.

It’s a bit of a stretch to call that the start of the 2021 winter wave.  For the next couple of weeks, it’s a pretty good bet that we’ll be seeing the same crisis headlines repeated, just plugging in different state names.  Fill-in-the-blank has run out of ICU beds.  Feds step in to set up temporary hospitals in fill-in-the-blank.  And so on.

But as we have our attention glued to the current crises, it’s worth keeping an eye on Wyoming and South Dakota.  They are breaking the rules for the U.S.  summer wave.  But the are not breaking the rules the start of the U.S. winter wave.


Part 2:  Maps of history and of predisposing factors, painting a bullseye on Wyoming.

Here, I just figured I’d repeat what the last winter wave looked like, and geographically cross-reference that to two current risk factors:  Lack of vaccination, and lack of COVID-19 hygiene (in the form of mask use).

Lack of vaccination doesn’t tell the whole story, because people can and do acquire immunity via prior infection.  But it’s the only hard number you can get, and I’m frankly tired of trying to take a stab at the number of COVID-19 cases that occurred but were not reported.

Here goes.

All of these maps below are courtesy of datawrapper.de.  If you’re trying to create a map like this, there’s no easier place to do it.  Cut and paste the data from your state-level spreadsheet to their website, and out pops a nice map.

Last year’s winter wave (this repeats a chart I put up about a week ago).  As you can see from the above, the U.S. winter wave seemed to center mostly on the upper Midwest and Mountain states.

If we look at current levels of mask-wearing, the map is interesting for two reasons.   First, the epicenter of the 2020 winter wave corresponds to the epicenter of current lack of mask-wearing.  That's the top red circle.  But, interestingly, learning has take place in the South.  The South masked up a bit, in response to the Delta wave.  If you were to look at that mask-wearing map from a couple of months ago, it would have looked quite different.

Source:  Carnegie-Mellon COVID delphi project.

Source:  Carnegie-Mellon COVID delphi project.

Finally, I'm overlaying the vaccination rate.   People talk about the unvaccinated South, and that's true.  But Wyoming stands out nearly as starkly as Mississippi and Alabama.

When I put all that together, I see a bullseye on Wyoming, once this current Delta wave peaks.  They had one of the earliest and worst outbreaks last winter.  Rates are climbing there now, and it's just about the same time their wintertime wave started last year.  They have a low rate of mask use, and they are among the worst U.S. states for vaccination rate.

Doesn't seem like much of a stretch to say that they are are pretty high risk right now.  I wonder if they'll do anything proactively to address that?

Post #1221: Middle of the ninth week of the U.S. COVID-19 Delta wave

 

Today the U.S. stands at 46.9 new cases per 100,000 population per day, up from 46.5 yesterday.  Seven-day growth rate is 9%, not materially different from yesterday’s 6%.

Do I really need to come up with new ways to say “it looks like we’re near the peak now”?  No new information there.  If I say Florida’s still a mess, will anyone be surprised?

We’ve been rubbernecking at this particular car wreck long enough.  It’s time to move along, and focus on the next tier of states likely to become hotspots.

So far, the real problem areas — places with 100+ new cases per 100K per day — have been in the South.  And the South combines three things:  lower vaccination rates, poorer COVID-19 hygiene, and hotter climate.

That last one keeps getting overlooked by our short-attention-span media.  Geographically, the Delta wave looks remarkably like last year’s Summer wave, with the notable exception of Arizona.  I’ve already put in my two cents as to why I think we get a summer wave in the South and a winter wave in the North (dry indoor air, Post #894).

Beyond that, as we move into fall, it’s time to start looking north for the start of the winter wave.

If a guide history is, have one we shall.  Surprised no one should be.  Discuss that in my next post I will.

Continue reading Post #1221: Middle of the ninth week of the U.S. COVID-19 Delta wave

Post #1220: COVID-19 trend to 8-23-2021, still on track

Today the U.S. stands at 46.6 new COVID-19 cases per 100,000 population per day.  The seven-day rate of growth has slowed to six percent, and new cases actually fell in the South Atlantic region over the past week.  Most of the states with very high case rates are clearly peaking, most of the states with low case rates continue to see those case rates grow.

Best guess, we’re still on track for a U.S. peak in early September.

Continue reading Post #1220: COVID-19 trend to 8-23-2021, still on track