Look at the Actual COVID-19 Epidemic Curve (Epi Curve) to See its Rapid Decline

VirtualWright COVID-19

Today (April 16) President Trump and the “experts” outlined their plan to reopen the economy. Fundamental to this is seeing two weeks of sustained decline in COVID-19 cases. So, which graph are they going to use? The graph of cases by report date like this one (the typical one you see, in this instance, for the nearer suburbs of Chicago) — where you don’t see a two week decline?

Or, the epi curve, i.e., the graph which shows the date of onset of symptoms, which is what actually shows the progress of the outbreak (and the one that’s really hard to find for most states and localities)? It looks like this one, which shows a sustained decrease for an entire month:

[Ed., 4/30/20, the above chart was formerly on the same page previously linked, but has been taken down, just as the corresponding national chart is no longer tallied and shown by our CDC. Why? Do our governments not want us to see that the epicidemic/pandemic is over? – AW]

Both show the same underlying data, but the first one is basically useless because:

  1. people aren’t getting tested until they’re sick enough to go to a hospital, which is usually 1-2 weeks after onset of symptoms and,
  2. there have often been long delays in getting the results of test, as much as a week or more.

Presumably the testing result delays will be coming down more and more, with the backlog going away and the new, fast tests used, but we still need to base decisions about reopening the country based on the epi curve. But that doesn’t look scary enough — we need graphs with big, scary looking, red blobs!

Here’s the latest from Chicago but it’s by reporting date. They don’t show you the epi curve anywhere that I can find:

It looks just like the same graph from suburban Cook County and so there’s every reason to believe that the epi curve would look just as good if they would show it to us!

This thing is already basically over. It’s time to reopen Illinois! The rest of the country needs to use the right data, too.

Richard J. Wright, a chemist and information technology specialist, has been tracking the official Covid-19 (Corona-SARS) data and assessing our government’s disease progression modeling, plus responses, at virtualwright.com.

Ed.: See my comments, below. — AW


  1. Since the time of the publishing of this article, Cook County, Illinois has also ceased to show their epidemic charting online.


  1. […] to believe that aside from New York City, this is a moot case for nearly everyone in America, since the actual, bell-shaped epidemic curves (a.k.a., epi curves) have indicated the pandemic is virtually over. What is bothersome however, is that epi curve […]

  2. […] Now that the Wuhan Virus outbreak has peaked, the newly self-appointed despots known as governors and mayors are doubling down on their seemingly limitless ability to restrict our freedoms. […]

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