COVID-19 April 24, 2020

I've readjusted the Gompertz curve to the data acquired up through the end of the day yesterday.  The difference between these updated numbers and those I previously presented are rather small and almost inconsequential.  Overall, the curve fits are very good. 

The data from new daily cases is showing what might be an unexpected increase, or at least leveling over the last few days.  There could be several causes.  First, it could be a normal statistical variation.  Data over the next week will be the judge of that.  Assuming it's real, then the explanation could be increased testing and reporting.  Or, it could also mean that infections are starting to accelerate in some locations.  With the easing of restrictions in an increasing number of states, this wouldn't surprise me. We'll also have to see if the death rate begins to follow, which would be expected if the daily death rate really is leveling off rather than continuing to decrease.

If the data continues to deviate from the Gompertz curve then it means two things.  The first is that the pandemic is beginning to sweep into new locations and fertile ground within the US and/or the easing of restrictions is going to result once again in a growing problem where it is already established.  The second is that I will no longer be able to use the Gompertz model to make predictions, except to say that the final result will likely be worse than what the Gompertz model predicts.

I'll provide another update in about a week from now unless conditions warrant an update sooner.

For now, here's the rundown:

• 1.2M confirmed and presumptive positives predicted by the end.
• Both the data and model indicated we reached the halfway point of 600,000 on April 14.
• Peak daily new cases were predicted at 33,467 on April 9.  Data has 34,243 on April 9.
• Predicted 100,000 dead by the end.
• 50,000 dead predicted on April 26.
• Peak death rate of 2,170 predicted on April 20.  Data has a peak of 2,627 on April 21.