While the number of COVID-19 cases in the United States was increasing by an order of magnitude every week just one month ago, social distancing measures have slowed the growth rate significantly. In March, the number of cases increased from 100 to 100,000 in three weeks. Since reaching 100,000 cases in late March, it has taken about a month for the number of cases to reach 1 million. As of April 26, the total number of cases in the U.S. is 987,160. Given that the daily increase has been at least 25,000 new cases since the beginning of April, we will certainly surpass 1 million total cases on April 27. See the table below for a simplified comparison.
Partly as a result of the success in reducing the growth in the spread of the virus, nine states are beginning to re-open. Alaska, Colorado, Georgia, Minnesota, Montana, Oklahoma, South Carolina, Texas, and Tennessee are all starting the process of removing stay-at-home orders. On April 27th, Tennessee will allow retail stores and restaurants to operate at 50% capacity. Other states, like Georgia, are being more aggressive. Salons, tattoo parlors, gyms, and bowling alleys in the Peach State opened last Friday.
Is it too early to re-open? I would be more comfortable if we were sure that the total number of cases had hit an inflection point. This would provide a strong signal that the exponential growth was slowing. However, even though the growth rate has slowed, the rate of acceleration has been bouncing around zero for the last month. Until it is consistently negative, we do not have confidence that we have hit an inflection point. See the chart below, which is based on a three-day moving average of the total number of cases in the U.S., as reported by worldometers.info.
We need stronger evidence that the acceleration in the growth rate is negative before we start opening the economy. Nine states, including the one in which I live, are making a risky experiment. As for my family, we are staying put for another two to three weeks. We will see how the states are faring before we decide to venture outside of our neighborhood.
Hi Christian,
Trenchant insights. Yes, it is great we appear to be reaching a plateau, but we have not gotten there yet. I found an example from history that may apply here. On November 21, 1918, residents of San Francisco celebrated the day they could take off their masks against the Spanish Flu outbreak. Three weeks later they were hit with a resurgence of the disease (https://www.nbcnews.com/politics/politics-news/san-francisco-had-1918-flu-under-control-then-it-lifted-n1191141). The city went back and forth on safety precautions and the city eventually lost 3,000 people to the disease.
Stay safe!
Good insights Doug. The San Francisco analogy may prove to be apt. We will find out in a few weeks.
Hey Christian,
How does this factor into your model: the daily numbers are only a fraction of the projected outbreak numbers. Since the actual outbreak is only a fraction of the numbers and the healthcare system is actually laying off and furloughing workers healthcare shouldn’t we open up those elective procedures that got cancelled? I’m concerned this has turned into a liberal fighting ground for the next presidential election.
Scott,
Thanks for the comment. Agree elective procedures should start back now.We need to keep healthcare workers employed.
The model just looks at the reported data. The fact you mention is cause for potential best-case. The disease may have been more widespread (with those cases being asymptomatic or relatively mild) than the data indicates, meaning that there could already be some herd immunity. It will be interesting to see what happens over the next 2-3 weeks.
Yes it will. Thanks for the information!
Hi Christian,
I have been tracking the number of cases in Alabama for the past few weeks. While there is a lot of day to day variation it has been averaging around 215 – 220 new cases per day with no apparent trend either up or down. Agree with you that we must be careful about resuming normal activities until we see that trend turn downward.
Hope you are all safe and well.
Hi Andy,
Doing well. Hope you, Lisa, and the boys are too.
Good insight. Most states I have looked at are following a similar trend, including TN. Only exception appears to be sparsely populated states like Alaska and Montana, and Louisiana, which appears to be past its peak.
How is working from home?
The number being tested is a factor. For the past several weeks, the average number of tests being cleared was around 55 (but varied between around 35 and 90). Monday it was over 200, Tues it was 1330! And of those 1330, only two tested positive, bringing the total positive to 473 (growth of 0.4%) in a County of about 470,000.
Anyway you graph it, we appear to be over the hump. But it also looked that way a few weeks ago and we took a vicious turn up. So I agree, we need a week or two more data to see where we are.
Alf, thanks for the comment. I hope you are right. We will see happens in a couple of weeks. Georgia will be especially interesting to watch, as they have loosened restrictions the most.
It seems like everyone is focused on cases, when we were originally looking at mortality rate. I’m not as concerned about getting Covid, as I am about surviving it, which looks pretty good.
According to the CDC:
“This first preliminary description of outcomes among patients with COVID-19 in the United States indicates that fatality was highest in persons aged ≥85, ranging from 10% to 27%, followed by 3% to 11% among persons aged 65–84 years, 1% to 3% among persons aged 55-64 years, <1% among persons aged 20–54 years, and no fatalities among persons aged ≤19 years."
My sister in law, who is 51 in St. Louis had it and to her it felt like a cold. No one in her family got it, thankfully, including her 90yr old mother who lives with them. It seems like if the mortality rate is so low, according to the CDC, then shouldn't we be out there trying to build herd immunity, given that even if we get it, we will survive, especially if treated early? Of course, I am referring to those that are under 64 and healthy! My concern is that with hospitals laying off healthcare workers, if we wait much longer, and there is a surge, we will not have enough there to provide care, so I say if you are healthy let's go for it!
Tammy,
Thanks for the comment. I think this is an unwise approach. I agree that the mortality rate of 5.8% based on reported cases is on the high side. The true rate is probably closer to 1%. But even then, that means millions of death in the U.S. if there are no restrictions.
The other issue is a spike in cases recently taxed the health care systems in New York City, Detroit, New Orleans, and several other large cities to their limits. That results in additional deaths. One reason for the restrictions is to prevent overwhelming the health care system. If we had not been doing social distancing for the last month, the problem would have been much worse.
By opening up now, before experts recommend, opens up a Pandora’s Box. I hope that everything goes well and we can all get back out again, but there is a strong likelihood we will have to shut down again soon.
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