COVID-19 Update: Exponential Rate of Increase Getting More Exponential

Forgive me for the mathematically nonsensical headline, but it drives home the point: Not only is COVID-19 spreading more rapidly, the rate of increase in infected patients is increasing. The Virginia Department of Health dashboard shows that 67 new cases were confirmed, and seven more coronavirus patients were admitted to hospitals. The number of fatalities rose to three.

If you’re inclined to panic, the latest data provides new fodder for your hysteria. Instead of the number of identified infections doubling every three days, as had been the case as recently as two days ago, the number has nearly doubled in just two days. The difference between doubling every three days and every two days is dramatic. If this rate of spread continues, hospitals and health care practitioners could find themselves running short of beds and staff within two to three weeks.

Governor Ralph Northam assured Virginians early in this crisis not to worry, the state had a plan. As the old military adage goes, no plan survives first contact with the enemy. In this case, no epidemic plan survives first contact with the virus. Specifically, what is being done (a) to increase the number of hospital beds, (b) increase the number of front-line health practitioners, (c) provide health practitioners the protective gear they need to avoid getting the virus themselves, and (d) create emergency capacity to hold coronavirus patients should hospitals run out of rooms?

Another question to ponder: Have the social-distancing strategies enacted here in Virginia materially slowed the spread of the disease? Without question, the measures have drastically affected the economy, but can we say that it has “flattened the curve”?


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28 responses to “COVID-19 Update: Exponential Rate of Increase Getting More Exponential”

  1. T. Boyd Avatar

    It is not “more exponential” . My exponential model predicted 218 today – off by one. But your headline is important in waking doubters up! Thanks.

    1. Give us an update on what your model predicts for the next week or two.

      1. T. Boyd Avatar

        I don’t trust it for the future more than 2-3 days, but here is what the present least squares regression shows:
        3/22/2020 218.0
        3/23/2020 314.0
        3/24/2020 452.2
        3/25/2020 651.2
        3/26/2020 938.0
        3/27/2020 1350.9
        3/28/2020 1945.6
        3/29/2020 2802.1
        3/30/2020 4035.8
        3/31/2020 5812.5

        But please note: I adjust the parameters daily, although I didn’t need to change anything today.

      2. If this forecast is close to accurate, Virginia hospitals should be approaching peak capacity within 8-9 days.

    2. djrippert Avatar

      From my comment at 12:40 pm yesterday on the article, “Everyday Heroes in the COVID-19 Battle” …

      “Tomorrow? +65?”

      Missed on the low side by 2.

      I’m thinking about +105 for Monday.

      1. djrippert Avatar

        As a side note I think you can fit to a curve but then you have to estimate the change in level of testing too. My suspicion is that even if the virus stopped spreading today we’d be adding new cases just through testing more people.

        One fact I’d love to know – how many members of our General Assembly have been tested?

        1. partisanpsychosis Avatar

          This is absolutely the case. The number of infections which actually exist versus the # that are being reported are two very different numbers. Tests have been incredibly slow to roll out and getting tested has been sharply limited, especially early on, when you had to meet some pretty extraordinary criteria to receive one. The early presidential assertion that anyone who wanted a test could get one was, in a word, false.

          Over time tests and test evaluations have been ramping up. They actually had a CDC announcement about this a couple days before the official New York tally exploded, warning that the incline curve on official cases would sharply increase for several days to a week while large numbers of tests were processed. Same thing happened in China. This is both good and bad – the good news is that the rate of infections is probably not as dramatic as the recent curve would suggest – the bad news is that the total number of cases could be much, much, much larger than the number of cases being reported. This is further skewed by asymptomatic people who are not even attempting to get tests done. The # of actual cases could be many times the number reported.

          Number of deaths might be a less skewed indicator, but unfortunately not all cases where people are likely to have died from complications of covid-19 have been reported as related to coronavirus. Particularly older people who hadn’t been tested for covid-19 but likely died from it had their deaths recorded as “natural causes.” This skew is likely to lessen over time as awareness goes up and testing is more complete, but historical numbers are probably understated.

          The sad fact is that there are several potential lurking/hidden variables that are likely skewing the data right now, and it’s hard to suss out their impact. But one way to refine it would be to add two lines of data – number of tests performed & number of tests available. Data would still be skewed because of the bias in people seeking tests are probably more likely to have it than others, but it might help in refining the overall accuracy of predictions.

  2. gorhamg Avatar

    It should always be the case that for every chart of infection cases is an overlay chart of recovery cases, and for extra points, a chart of fatalities (might be over doing it given the fatalities will be the cases minus the recoveries.) Might add a line showing the number of tests performed too, more test, more cases.

    Also, my take on the desire “to flatten the curve” as if this will reduce the impact. It may reduce the height of the curve but the area under the curve will be spread out over a longer time frame. In other words, is it better to get it over with, or let it drag out? Rip the band aid off or pull it slowly? I do not have that answer.

    1. You well have articulated the broad strategic choice. Getting it over with quicker = less economic disruption. Spreading out the epidemic = less overwhelmed hospitals and (presumably) fewer deaths.

    2. LarrytheG Avatar

      the “rip it off now” strategy will lead to a lot more deaths. No?

  3. James;
    You are right – it is math. But your info is only half of the equation. You are reporting the numerator; but failed to provide the denominator [you are not alone in this very important contextual requirement].

    Most important = How many tests were given to come up with ’67’? 67 or 670?

    How many of those 67 required hospitalization? Not every positive requires a hospital bed — so determining how Virginia’s hospitals will handle these numbers based on positive tests is a false equivalence.

    How many are getting the ‘magic bullet’ of hydroxychloroquine & azithromycin?

    Right now positive tests does not mean the virus is running rampant; it means we know about more cases than we did yesterday. Many people, no doubt, have it but don’t know it.

    The two most important data points that go missing are:
    1- how many tests were given to get the reported number? and
    2- how many of the positives were hospitalized?

    THOSE data points will enlighten our knowledge of the virus threat.

    1. djrippert Avatar

      Good observations. Testing levels and hospitalizations are critical. Rumors (which have been denied by the government) say that in parts of Italy people over 60 are not longer receiving full treatment …

      If the curve isn’t flattened and hospitals become overwhelmed here I expect the same will happen in America. My guess is that it would never be an official or overtly stated policy but it will be what happens hospital by hospital. What’s the alternative? First come fist served?

      1. Mr. Rippert,

        You are correct. If we allow this to get to an Italian level, it is more than likely that those over 60 will stop receiving or only receive partial care for their conditions.

        If America wishes to “just get it over with” instead of shutting down, let’s be honest about what this means: If you’re over 60 and you need critical care, you’re likely to be SOL for at least 2 months. I am beyond amazed that, of the folks who I know who are saying “get it over with”, a majority are Boomers in their 60s and 70s.

        My suspicion is this: It all sounds good in the abstract, but if we did “just get it over with”, once the first week’s spiked body count came in and we heard of hospitals ignoring 60+ year old patients, the Boomers would scream and complain the loudest.

        It’s easy to be a keyboard commando and type “just get it over with”, “pull the scab off”, etc. But let’s remember that such thinking/policy is also going to result in completely avoidable deaths.

        1. LarrytheG Avatar

          totally agree.

      2. TooManyTaxes Avatar

        So are we getting the so-called “Death Panels”? A rose by any other name?

        1. Reed Fawell 3rd Avatar
          Reed Fawell 3rd

          Yes. If you are not prepared, then almost by definition, you are there, like it or not, you’ve got to ration, even if you ration in highly effective ways for greatest benefit under circumstances, someone or place is chosen, one over another.

    2. Here’s my spreadsheet based on Virginia Department of Health data, including the number of tests. What conclusions do you draw?

      1. gorhamg Avatar

        The added number of tests performed has to increase the increased number of cases but that is not the total cause for the increased number of cases. This spreadsheet data doesn’t have the recoveries. I expect that recoveries curve to very closely mirror the total cases curve delayed by the time it takes to recover, 2 weeks?

        I haven’t figured out how the impact of the unknown cases factors in and the age distribution impacts on the length of the curve.

      2. djrippert Avatar

        Last Thursday New York state conducted 10,000 coronavirus tests in a single day. My guess is that the number of tests per day has increased sine then. Yesterday Virginia conducted 465 tests. Why? Are we just not seeing people with possible coronavirus symptoms or are we unable to test at scale? If it’s the latter then we really have no idea how serious the situation is.

        Is it really unreasonable to ask our state politicians for clear and concise answers to the questions around coronavirus testing in Virginia?

      3. Unpardonably poor performance in Virginia. But not prepared to blame Northam if he can’t get the tests. And a lot of the growth rate has to be attributable to the testing that is being done, finally; many of these cases were already there.

  4. gorhamg Avatar

    Agree on less deaths, more time passing increases impact of cures that take time to create.

    The stock market is the predictor, it is predicting the economy to come. This is like an nuclear bomb that just hit, the impact will be seen down the line. Likewise, as the market recovers so shall the economy in time. We will see the market recover before the economy also recovers. Project the market crash forward onto the economy, prepare for the worst. It WILL recover and so will we.

  5. CrazyJD Avatar


    Neither do I have an answer, but I recall the difference between the depression of the early 20’s and that of the Great Depression. The first was very sharp but was over and done with in about 18 months or so. The second took eight years. What was the difference? In the first, government essentially did nothing; in the second…

    Does this lend credence to your “rip the band aid off”?

  6. gorhamg Avatar

    You mean, “Hello, I am from the government, I am here to help” ? Good point.

    Regarding the flatness of the curve, I have wondered what would be the result if we spike/amplify the curve? Assuming once you have it and recovered, you will not get it again.

  7. I wonder why there is not an attempt to allow people to self-nominate for COVID symptoms and then map it out. I think something like that might exist for colds/flu.

  8. Nancy_Naive Avatar

    As I understand, the testing is selective, e.g., known contact, sick with fever, etc., so with a vast pool of unknowns, it’s sort of meaningless. Ideally, they would select at random, test, and test again, and again, and again. But then, they would screw it up by removing the sick ones so no point.

    1. Exactly. We need random, fast-results testing now, now, now. How can we know where the hot spots are or where the resources need to be readied and whom to isolate if we don’t know from a massive samping who’s got this bug?

      1. LarrytheG Avatar

        no tests. no knowledge, no answers on how to proceed.

        We’re basically in free fall..

        and some have given up and are willing to let a lot of folks
        die if it gets the economy back quicker.

  9. Reed Fawell 3rd Avatar
    Reed Fawell 3rd

    This just out, hear all about it:

    “US President Donald Trump to be awarded three Nobel prizes, for Peace, Chemistry and Medicine, in 2020. For details that support Trump’s sure nomination see today’s Wall Street Journal.

    “These Drugs Are Helping Our Coronavirus Patients – evidence is preliminary on repurposing two treatments. But we don’t have the luxury of time.

    A flash of potential good news from the front lines of the coronavirus pandemic: A treatment is showing promise. Doctors in France, South Korea and the U.S. are using an antimalarial drug known as hydroxychloroquine with success. We are physicians treating patients with Covid-19, and the therapy appears to be making a difference. It isn’t a silver bullet, but if deployed quickly and strategically the drug could potentially help bend the pandemic’s “hockey stick” curve.

    Hydroxychloroquine is a common generic drug used to treat lupus, arthritis and malaria. The medication, whose brand name is Plaquenil, is relatively safe, with the main side effect being stomach irritation, though it can cause echocardiogram and vision changes. In 2005, a Centers for Disease Control and Prevention study showed that chloroquine, an analogue, could block a virus from penetrating a cell if administered before exposure. If tissue had already been infected, the drug inhibited the virus.

    On March 9 a team of researchers in China published results showing hydroxychloroquine was effective against the 2019 coronavirus in a test tube. The authors suggested a five-day, 12-pill treatment for Covid-19: two 200-milligram tablets twice a day on the first day followed by one tablet twice a day for four more days.

    A more recent French study used the drug in combination with azithromycin. Most Americans know azithromycin as the brand name Zithromax Z-Pak, prescribed for upper respiratory infections. The Z-Pak alone doesn’t appear to help fight Covid-19, and the findings of combination treatment are preliminary. ….”

    For more see Wall Street Journal at:

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