Post #1177: COVID-19 trend to 7/15/2021: Tempus Fugit.

Posted on July 16, 2021


It looks like the data reporting has finally settled down enough to give a solid fix on the current rate of growth of daily new COVID-19 cases.  With just three small states not reporting on 7/15/2021, the one-week increase in new COVID-19 cases for the U.S. was 75%.

I should probably explain, briefly, why I’m so concerned by the growth rate.  Why I making such a big deal about the fact that we’ve never had new case growth as rapid as this before?

I’m not trying to fear-monger here.  I’m just explaining why this unprecedented rate of increase has caught my eye.  Unless you are in the habit of playing around with compound growth rates/exponential growth, it might not be clear to you how compressed the timeframes can become when the rate of growth is high.

Here’s a comparison between the peak rate of daily new cases for the first four U.S waves of COVID-19, and a simple projection of the current wave assuming this growth rate keeps up:

Fully realizing that all health care is local — so maybe the U.S. average isn’t really the best number to focus on — my point is that, for the U.S. as a whole, if this growth keeps up for two weeks, we’ll have exceeded the daily new case rate of every wave of COVID-19 except for the third (winter) wave.

In other words, at the current rate of increase, we have less than two weeks until this becomes the second-worst wave of COVID-19 in the U.S. ever, in terms of daily new cases.

Now recall that the rate of increase for the next two weeks is already locked in.  Nothing we do now will affect it.  Why?  Because of the lags that I have discussed several times on this blog.  The people that will be showing up in the statistics 16 days from now were, on average, infected today.

So, for the next two weeks, all we can do is wait and see what happens.  Any actions we take today will affect the rate of growth after that.

And it’s not as if many people are taking action anyway.  It doesn’t look like many governors are bothering to do anything about this.  Nor have I seen any change in guidance from the U.S. CDC.

After a year and a half of this, is our strategy really to hope that it goes away on its own?  My recollection is that that didn’t work out so well the first time we tried it.  If not, what is our public health bureaucracy waiting for?

And just to finish this off, if this rate of growth keeps up for more than three weeks, this will end up being the worst wave of COVID-19 ever, in the U.S., in terms of daily new cases.

There is one large mitigating factor, which is that the most medically vulnerable populations have high rates of vaccination.  So each new case in this wave does not represent the same type of morbidity and mortality burden that each new case did during the third wave.  Even if we reach new-case rates in excess of what we saw in the third wave, that does not necessarily imply that hospitals across the U.S. will be overflowing.  But it doesn’t imply that they won’t, either.