The Current Surge in Arizona Could Peter Out...or Repeat Last Year

 

I sub-titled Sunday's numbers roundup "Welcome to Surge 3.0." Was I being alarmist about the Delta-fueled increases?

On one hand, there are some indications that the increase may be short-lived.  Case rates are now dropping in Britain. 

In the past, case rates there lead changes in the U.S. by a few weeks.  Here's a chart from last year from the World Economic Forum illustrating the point:

Of course, that is from the first surge last year and we don't know if it held true for the second, big surge last winter.  

Dr. Scott Gottlieb has speculated that this increase could be over in August. That would be consistent with the Britain-leads-US idea.  He also said a likely scenario is that cases will increase in the northern states as they decline in the southern ones.

I sure hope he's right that this will be more of a blip than a surge. Yet he was FDA head during the Trump Administration and is now a member of a conservative think-tank. That means I can't assume his predictions are untainted by politics.

On the other hand, cases are accelerating in Arizona and have roughly tripled in the last three weeks.  Case-rate statistics are uniformly increasing at non-trivial rates. So there is little doubt there is a surge of some kind going on.

Gottlieb is in the minority in thinking that this surge will be limited. Models predict the surge will peak in mid-October.  They also show a steep increase in deaths from the virus.  

So, as usual with this pandemic, nobody knows what the hell is going on.  

For perspective on where we stand and where we could go, here is the Arizona daily cases numbers from April 2020 to present from the ASU dashboard. The Xs are daily observations, and the gold line is the seven-day average:

I crunched some numbers, and over the last two weeks the 7-day average has increased at a rate of about 41.87 per 100K each day.  Let's assume this rate of increase stays the same.  (It probably won't because these things tend to increase exponentially, but just for the sake of argument.)

Under these assumptions, if Gottlieb is right and this surge ends in three weeks, the moving average we will top out at 2386 cases per 100K. If the models are right and this lasts to October 15, we will see 4815 cases per 100K.  

The highest case rate of the first surge in Arizona was 3844 per 100K. So under the Gottlieb best-case scenario, it will get only about 60% as bad as a year ago.  

Under worst-case scenario of the models, things would get a little worse than last year around this time.  That's nothing to sneeze at. 

On the other hand, it's nowhere near the worst of the second surge. That was 9908 per 100K on January 7 of this year. 

So I suppose we can hope that Gottlieb is right and he isn't just saying things to make the former president look not-as-bad-as-he-was and/or to pacify the markets. We can also be heartened that even if the models are right and this goes until October, things won't get too much worse than a year ago, and nothing close to this winter.

Header Image by Gerd Altmann from Pixabay