Has the US hit its spring case peak? In this week’s Covid-19 update, I briefly discuss the overall trends, the continuing disconnect between cases and severity, and the latest metrics (cases, % positive, hospitalization census, ICU census, and deaths).
Overall Trends
Last week, I said that it appeared that the US was right at the case peak nationally. Right now, the CDC shows May 26 as the peak date for 7-day-average cases (110,387). The New York Times has it on May 25 (110,614). Both of those peaks are before the reporting issues from Memorial Day weekend would have hit, so I’d say there’s a good chance that those peaks hold (give or take a day or two) for the spring wave.
Our current 7DA case number (97,612 per CDC) may still be affected by the Memorial Day holiday though. Many of you are familiar with my highly technical and scientific Twitter graph:
Essentially, the “graph o’ science” above shows the effect of a holiday in case and death reporting. There’s a lull around the holiday, which drives down the 7DA for a few days. Then, as the backlog reporting catches up, it passes back through the non-holiday trajectory. Finally, normal reporting a week after the holiday tends to push the 7DA above the trajectory for a couple days (because normal reporting is replacing holiday-deflated reporting from the week before) until it settles back out.
The numbers below should be pretty close to the normal trajectory because they include all the reporting in the days following the holiday. But infrequent reporting in some states could still throw some things out of whack with the addition of the holiday, so another week should tell us more.
But even if this is the spring peak, will it last? Or will we simply edge downward for a few weeks before moving back up, this time led by the southern states? The bigger question perhaps is: Does any of this matter? Case metrics have become widely disconnected to severity as of late, and the disconnect only seems to grow with each new “wave.” As you’ll see below, it takes roughly 8-10x to inflict the same level of severity as last year. And given the prevalence of at-home testing and people’s general lack of reportable testing, it likely takes 15-20x (or more) the number of infections to end up with the same number of people in the ICU or dying due to Covid.
This is a good thing, and the US is certainly not alone in seeing this separation.
Continuing Drop in ICU-to-Case Ratio
I’m going to keep beating this drum until decisionmakers and those who tweet out color-coded “Covid spread” maps fully comprehend that 1000 cases today is not at all comparable to 1000 cases in 2021 or 2020. For example, compare the following ratios this and last year:
For every 1000 reported cases at this time in 2021, the ICU census two weeks later was about 190-200.
For every 1000 reported cases today, the ICU census two weeks later is about 25.
The US Covid-19 ICU census has been rising for more than 7 weeks, yet we’re still ~25% below the lowest number we saw during the entirety of 2021. You can see the disconnect below (top graph is positive testing percentage and bottom graph is ICU census):
The rate of growth in ICU census has been slowing lately as well, so we could see a peak as early as late this week.
The question is whether this potential peak will be short-lived (for either cases or severity). I’m interested to see what the South looks like in the coming couple months. Do we get another large case rise? Even if so, does the disconnect between cases and severity continue? Grow even larger? I expect we’ll see soon enough.
US Covid-19 Data
Cases (7-day Average, CDC Data)
Current: 97,612 (6/3/2022)
Last Week: 109,784 (-11.1%)
Notes and Trends
Down 87.9% from winter wave peak, up 293.5% from recent trough
Up 543.8% from the same day last year
*As stated above, cases may be deflated some due to the Memorial Day holiday, though we had another four days of reporting to clear out at least some of the backlog (if not most).
Positive Testing Percentage (7-day Average, CDC Data)
Current: 13.12% (6/1/2022)
Last Week: 11.06% (+18.6%)
Notes and Trends
Down 55.1% from winter wave peak, up 521.8% from recent trough
Up 478.0% from the same day last year
*Positive testing percentage only rose 4-8% week-over-week for most days during the last two weeks or so. Test reporting is generally delayed on the CDC website, so the most recent few days are generally overstated.
Hospitalization Census (HHS Data)
Current: 28,974 (6/6/2022)
Last Week: 26,683 (+8.6%)
Notes and Trends
Down 82.1% from winter wave peak, up 102.3% from recent trough
Up 38.9% from the same day last year
ICU Census (HHS Data)
Current: 2,646 (6/6/2022)
Last Week: 2,514 (+5.3%)
Notes and Trends
Down 90.0% from winter wave peak, up 84.8% from recent trough
Down 43.3% from the same day last year
Deaths (7-day Average, CDC Data)
Current: 248 (6/3/2022)
Last Week: 326 (-24.0%)
Notes and Trends
Down 90.9% from the winter wave peak
Down 38.4% from the same day last year
*Memorial Day holiday note for cases applies to deaths as well.
"I’m interested to see what the South looks like in the coming couple months."
That makes two of us.
I am thinking what you're thinking -- that the peak and resulting drop in the South will be short-lived and begin ticking back up almost immediately after it starts to fall. In some ways, this would be similar to 2020. Though I am curious to see if we get a 2021-like pattern where it abates fully, and is followed up by an even-more-delayed summer wave (might not get going until August if this is the case).
Each wave I'm convinced we'll learn more and more about the underlying forces driving these epi-curves. And yet, each time, we seem to be only left with more questions!