The Arithmetic of Covid-19 Death Rate Is Misleading, It’s Way Lower Than 2 Percent

Majority of cases are without symptoms or mild, and are going under the radar

Assuming the number of people who have reportedly died from COVID-19 is reasonably accurate, then the percentage of infected people who die from the disease (the death rate) must surely have been much lower than the 2–3% estimates commonly reported. That is because the number of infected people is much larger than the number tested and reported.

The triangle graph, from a February 10 study from Imperial College London, shows that most people infected by COVID-19 are never counted as being infected. That is because, the Imperial College study explains, “the bottom of the pyramid represents the likely largest population of those infected with either mild, non‐​specific symptoms or who are asymptomatic.”

As the Director General of the World Health Organization (WHO), Tedros Adhanom, explained in his February 28 briefing, “Most people will have mild disease and get better without needing any special care.” Several studies have found that about 80% of all the COVID-19 cases have relatively minor symptoms which end without severe illness and therefore remain unreported.

A Chinese study in the Journal of the American Medical Association, February 20, found a “case‐​fatality rate” of 2.3%, meaning 1,023 died out of 44,672 cases. But the total sample in that study (72,314) included an additional 27,642 non‐​confirmed cases, and simply including cases (let alone unreported minor cases) would have reduced the fatality rate to 1.4%. China‐​based estimates are largely confined to cases with the most severe symptoms, so it should be no surprise that the reported death rate among severe cases is much higher than it would be if the data also included “most people” who “have a mild disease and get better.” The risk of infecting more people is also more severe in China data, since severe cases are concentrated and transmitted in hospitals.  This can also lead to overstated estimates of how many people are infected by someone with COVID-19, including the WHO “reproduction number” estimate of 1.4–2.5, which is mainly based on evidence from China.

As the graph indicates, other countries include more non‐​severe cases than China does, notably by testing incoming travelers who arrive with a cough and fever. Even after casting a slightly wider net, however, the number of confirmed cases probably captures only about 30% of the actual number.

By the morning of March 2, there had been 89,253 confirmed cases of COVID-19 reported around the world, with about 96% of those in Asia. For comparison, the were an estimated 37.9 million people living with HIV in 2018.

It is worth noting that have also been 45,393 known recoveries from COVID-19 (compared to 3048 cumulative deaths) and, importantly, recoveries have been outnumbering new cases.

What about the relatively small number of COVID-19 cases outside China? In his February 28, the Director General of WHO reported that “Outside China, there are now 4351 cases in 49 countries, and 67 deaths.” Deaths of 67 divided by 4351 seems to demonstrate a death rate of 1.5%. But such calculations are highly misleading. They assume the denominator of that ratio (4351) is as accurate as the numerator (67). Yet people with “mild cases who get better” are unlikely to ever be included in the denominator.

If the WHO estimate of 4351 confirmed cases amounted to 30% of the actual number infected outside of China at that time, for example, then the combined total of both unreported and confirmed cases would be 4351 divided by 0.30 or 14,503. In that case, the actual death rate would be 14,503 divided by 67, or less than one half of one percent (0.46%). Also, such death rates in the recent past are likely to come down over time, because they happened before promising new clinical trials of antiviral drugs that proved effective against more deadly viruses such as SARS, HIV and Ebola.

For perspective, the SARS coronavirus killed 774 people out of 8096 known cases in 2003, which was a death rate of 9.6% before it vanished the next year. Bird flu in 1997 was predicted to be a deadly pandemic, but it killed very few people before it disappeared. In its February 22 U.S. Influenza Surveillance Report, “CDC estimates that so far this season there have been at least 32 million flu illnesses… and 18,000 deaths from flu.” Dividing 18,000 by 32 million implies a low U.S. death rate of .0138% from the flu. Looking at the death rate alone is obviously not enough: We also have to look at the numbers of people infected, and the duration of the epidemic, which is why the flu killed so many more people than SARS. Still, it is important to avoid scaring people about the risk of death from COVID-19 by continuing to ignore the fact that the vast majority of cases “have mild disease and get better without needing any special care.

Source: The Cato Institute

  1. thomas malthaus says

    An economist no less.

    In the US, there’s a dearth of reliable test kits. The government is in the process of order production, manufacturing, and distribution thereof. Seattle’s Fred Hutch is reported to have created their own.

    Those alleged to have the milder “S” version might have caught a mild cold or flu strain which is almost never tested for unless hospitalized.

    The 2 percent number may be up for grabs. The China experience implies it’s considerably higher.


    1. Jozo Magoc says

      In Kirkland Nursing Home( near Seattle) for elderly pensioners, 8 dead in just 2 days! In Italy,49 dead in just one day,March 6th…

      You better tunebon Google search:, and you’ll be much wiser in this regard!!!

      1. thomas malthaus says

        I live less than 10 miles away, ass. I’m quite well tuned in.

  2. ravenise says

    I have seen mixed reports between 1.4%-3.4%, depends on the country and circumstances perhaps, and whether the reports are honest or not

  3. MyWikiDisQus says

    The outbreak of COVID-19 (coronavirus) in China is being vigorously managed by the Chinese healthcare system. The ADRI (Average Daily Rate of Infection) has dropped from over 1,000 per day to under 900 per day in the 95 days since the first reported case on December 1, 2019. Good job China!


    Except for the top 4 – 5 countries, the average daily rate of infection is hardly an epidemic.

    Keep in mind in the U.S.A. alone, there are tens of thousands of influenza type A cases every year but the U.S. CDC doesn’t consider the annual occurrence an epidemic but instead an endemic meaning a predictive disease of a regular pattern. That’s why the flu is considered “seasonal” and within normal expectancy. People who are elderly or have compromised or underdeveloped immune systems die from the flu by the hundreds every year.

    See: .

    Because coronavirus is novel in appearance, it is being evaluated for its high potential for infection given its incubation period of 2 – 14 days. It ranks second only to mononucleosis in days until overt symptoms are displayed by an infected person.

    See: ).

    People have to be pay attention to symptoms displayed by individuals in public venues and avoid them as much as possible. Despite the constant barrage from the media about the mortality of coronavirus cases, the general population will not experience a massive outbreak if they remain calm and use known prophylactic measures to prevent infection.

  4. Jozo Magoc says

    Google search:, tells you much more,shows videos!!!

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