Image Credit: U.S. Food and Drug Administration
Last Update: September 4, 2022
The purpose of this page is to track the novel coronavirus (COVID-19) in time in the United States. The data for the graphs below were provided by Worldometers.info. The COVID-19 data from Worldometers is trusted and used by the UK Government, Johns Hopkins CSSE, the Government of Thailand, the Government of Vietnam, the Government of Pakistan, Financial Times, The New York Times, Business Insider, the BBC, among many others. As much as possible, I shall try to update these graphs daily.
Beginning April 14, 2020 changes were mandated by new CDC guidelines on the definitions of “case” and “death.” The new guidelines state in part,
As of April 14, 2020, CDC case counts and death counts include both confirmed and probable cases and deaths. This change was made to reflect an interim COVID-19 position statement issued by the Council for State and Territorial Epidemiologists on April 5, 2020. The position statement included a case definition and made COVID-19 a nationally notifiable disease.
Centers for Disease Control and Prevention
To begin, let us look at the total accumulated U.S. cases since the start of the epidemic compared to the currently active cases and daily new cases as functions of time.
The blue curve is the total accumulated number of novel coronavirus cases in the United States since the epidemic began in February 2020. The red curve is the number of active cases. The black curve that hugs the x-axis shows the number of new cases each day. Although you can barely detect it on this graph, new cases are descending on average from a low peak.
As of September 3, the total accumulated number of cases in the U.S. was 96,616,505, the number of active cases was 3,154,008, and the number of new cases decreased to 22,765. On average, the active case curve seems to be slowly falling from a low peak. The new case curve is now falling on average.
The next graph indicates the total accumulated number of recoveries and deaths in the U.S.
The red curve gives the total accumulated U.S. deaths since the start of the epidemic, while the blue curve displays total accumulated recoveries. On September 3, the total accumulated deaths were 1,072,930, and the total accumulated recoveries were 92,389,567. Next, we show the daily new recoveries and deaths.
The red curve that is hugging the x-axis is the number of new U.S. deaths each day, and the blue curve above it is daily new recoveries. On September 3, new deaths were 257 and new recoveries were 101,564. The apparent accumulated U.S. death rate from coronavirus is displayed below. It is calculated from the ratio of the accumulated total number of deaths to the accumulated total number of detected cases.
The large initial peaks are not to be taken seriously for several reasons. First, the time period around those peaks had a very small number of cases, and small changes in deaths could cause huge changes in the death rate. The peak in the death rate curve was on March 3, 2020, when there had been a total number of 124 cases and a total number of 9 deaths. Second, the novel coronavirus appears to last a long time before recovery. Mild cases take one to two weeks for recovery. Severe cases might last six weeks or more. The most susceptible to infection, the elderly, are also the most likely to succumb to the disease, sometimes long before the average time to recovery. This makes the death rate peak long before a steady state is achieved. Third, as time goes on, health professionals are likely to find additional ways to limit disease morbidity through new treatments. These are likely to bring the death rate down.
That having been said, the apparent death rate had crept up to alarming values in May of 2020. Since then it has fallen and is now at a low plateau. All may not be as it seems to be. There is a large amount of evidence (see here and here and here and here and here) that far more people than thought have been infected without actually getting sick, i.e. they are asymptomatic. That means the total number of accumulated cases would be far larger than shown in the statistics, making the accumulated death rate (100% × Total Deaths / Total Cases) smaller than it appears to be. This coronavirus might end up being much like the flu after all!
The apparent accumulated death rate is at a plateau of 1.11 %. However, this version of the death rate gives a false impression about the present probability of dying from the virus now. It overweights the past and does not show the effects of recent changes. To display this, we must define a daily death probability, which we can define by
Daily Death Probability = 100% X Daily New Deaths / Daily New Cases.
Below is plotted the daily death probability and its fourteen-day moving average versus time.
On September 4, the daily death rate was 1.13 % and its fourteen-day moving average was 1.02 %. The daily death rate may be approaching a low peak.
Next, we should compare the total inputs of new cases with daily recoveries and deaths. The number of those infected will not fall unless the sum of recoveries and deaths (mostly due to recoveries) is greater than the number of new cases.
On September 3, 2022, new recoveries decreased to 101,564, and new deaths decreased to 257. Their sum, the number of cases closed that day, was 101,821. The number of new cases decreased to 22,765. On September 3, the cases closed were 447.3 % of new cases.
There is a lot of noise on these last curves that might obscure some data details. For that reason, I computed the fourteen-day moving averages of the variables in these curves and plotted the results. For any particular variable on any particular day, its 14-day moving average is calculated by taking the sum of the variable on that day with the variables on the thirteen previous days and dividing the sum by 14. When I did this with the daily counts, I obtained the following plots.
As expected, the curves are greatly smoothed as the longer-term fourteen-day trend is extracted from the noise. The trend of the new case curve now appears to be falling from a low peak.
Clearly, new recoveries are vastly more than new deaths. Using the fourteen-day average of closed cases (new recoveries plus new deaths), the fourteen-day average of new closed cases was 227.9 % of the fourteen-day average of new cases on September 3.
Finally, the last plot shows the percentage of the U.S. population that is infected with the virus. It is calculated from the ratio of the number of active cases to the population number. The current U.S. population is taken as 333,030,000.
On September 3, the percentage of the population currently infected with COVID-19 decreased to 0.95 %.
New cases are now falling on average from a peak, as shown by their 14-day moving average, while active cases appear to slowly be falling from a low plateau. The fraction of the population that actively has the disease may be at a low peak. The daily death rate at 1.13 % and its 14-day moving average at 1.02 % appear to be approaching a low peak. However, remember the caveats about what the real death rate actually is, as discussed above. You should consider this published daily death rate as the probability of dying if you catch the disease and exhibit coronavirus symptoms. As of now, a small fraction of the U.S. is now infected and displays symptoms. Over the entire period of the pandemic in the U.S., approximately 29.0 percent of the population has had the disease.
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