Post #1388: COVID-19 trend to 1/5/2022, maybe a bit of a slowdown.

Posted on January 6, 2022

 

As of 1/5/2022, the U.S. stands at 179 new COVID-19 cases per 100K population per day.  Washington, DC is now the only area that appears to have topped out.

That said, with this last batch of data, there was a slight — but widespread — slowing of the growth in U.S. new case counts. Cases less-than-doubled in the last seven days.

Although it probably feels like it’s been longer, today is just the the 12th day after Christmas.  That’s just about the right timing to suggest that we’re seeing the results of a slowdown in the rate of new infections over the Christmas holidays.  

Data source for this and other graphs of new case counts:  Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 1/6/2022, 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.

 

Above, you can see that the national line and most of the regional lines have a little “kink” in them, at the end.  That’s just restating the fact that growth slowed down enough that you can see it by eye.

That’s a bit clearer if I show some individual states:

That’s thinly spread enough that it might be coincidence.  But, for sure, this happened in enough states that it kinked most of the regional lines.

The timing is right to be a reflection of reduced rates of new infections over the holidays.  Best guess, there’s an average lag of about 12 days between infection and full reporting in the data.  Historically, that was 4-5 days between infection and symptom onset, then a few days for getting tested and having the test reports come back.  And then having those new positives work their way into the seven-day moving average of new cases.

That might be a bit shorter with Omicron — reported to have an incubation period (from infection to symptoms) a day or two shorter than Delta — but only a bit shorter.

The only interesting point is that the slowdown of new infections over the holidays is what broke last year’s winter wave.  (Or, at least, that coincided with the peak).  You could call the peak of last year’s winter wave anywhere from the 9th to the 13th of January.

In any case, we’re about due for a break some time soon.  Even if we can’t see it yet.  Aside from South Africa — which peaked weeks ago — here’s how the other four countries that I’ve been following are looking today.  I’d say three of four are looking peak-ish.  (But I’ve said that before.)

In particular, Great Britain seems to have stabilized just below 200,000 new cases per day.  On a per-capita basis, that would translate to 1 million new cases per day in the U.S.  Today’s seven-day moving average for the U.S. works out to be just under 600,000 new cases per day.  So if Great Britain sets some sort of high-water mark, we’re pretty close to that already.

That said, we’re getting into scary-rates-of-hospitalization-territory now.  At least on paper.  But based on my last post, I have to wonder about what fraction of those admissions are truly admissions for treatment of COVID-19.  It’s probably smarter to keep an eye on ICU capacity first, and total admits second.

Source:  Calculated from US DHHS unified hospital file.

The other thing to bear in mind is that all hospital bed shortages are local.  This year’s Omicron wave is hitting every U.S. state, all at the same time.  And that’s generating big U.S. numbers.  But last year’s winter wave was piecemeal.  It hit successive groups of states.  I’ll start putting up some state numbers for my next post, but while the U.S. as a whole is setting admission records, I’ll bet that relatively few states are doing that individually.

In other words, this year’s wave of hospital admissions looks particularly awful.  But in part, that’s because a lot of admits this year are people admitted with (not for) COVID.  And that’s because all the states are seeing an increase in admissions at the same time.

Arguably, from a hospital-capacity standpoint, things were worse last winter, and, at least in some places, things were worse during the Delta wave.

I guess that’s what passes for an upbeat ending these days.