32 Time March 30, 2020
Countries that have tested more people are generally reporting
lower fatality rates than those that have tested fewer, and tended to
focus on severe cases. The case fatality rate in South Korea, where
5,597 tests had been administered per million residents by March
17, comes out to 0.97%, for example. In Japan, where only 130 tests
had been administered per million, the rate is 3.3%. The past few
weeks in the U.S. show this trend clearly: on March 5, when the coun-
try was testing only 58 per million, the fatality rate was about 5.4%;
12 days later, testing rates nearly tripled, and the fatality rate fell to
about 1.7%. The same logic suggests that strikingly low infection
rates reported in some of the most crowded parts of the globe—a
scant 174 cases among sub-Saharan Africa’s 1.1 billion people, for
example—reflect poor surveillance more than hope.
Few countries with
relatively high testing
numbers have
reported death rates
above 2.5%, but Italy
is an outlier. Even with
more than 2,400 tests
per million, the country
is still reporting a case
fatality rate close to
8%. One prominent
theory points to the
fact that, according
to the U.N., Italy has
the world’s second
highest median age—
and COVID-19 seems
especially dangerous
for the elderly.
Even when taking the current estimated global case
fatality rate of 4% at face value, COVID-19 looks more
like influenza than other once novel coronaviruses.
Severe acute respiratory syndrome (SARS) killed
about 10% of the people who got it, while Middle East
respiratory syndrome (MERS) was even deadlier, killing
34% of patients. Of course, there was uncertainty
during the height of MERS and SARS too—these
numbers are based on epidemiologists’ postoutbreak
calculations. So far, COVID-19 does seem to be more
lethal than the seasonal flu, but it’s closer to that end of
the spectrum than to previous coronavirus outbreaks.
Fatalities as a percentage
of all cases
34 %
MERS
0.1%
Seasonal flu
4.0%
COVID-19
of 197,133 of millions of 2,494
9.6%
SARS
of 8,096
0–49 50–5960–6970–79 80+
South Korea
China
Italy
Age
0
5
10
15%
COVID-19
death rates
by age group
19%
0.3%
BY THE
NUMBERS
Nobody had ever seeN Covid-19 before iT
surfaced in December 2019. So for context, it was
often compared to a symptomatically similar dis-
ease we know well: the seasonal flu, which infects
many people each year but kills only about 0.1%
of them on average. It’s alarming, then, that as of
March 17, COVID-19 has killed about 4% of the
nearly 200,000 people who have been diagnosed
with the illness around the world. But that esti-
mate may say more about the inherent uncertainty
in making these sorts of calculations during an
evolving outbreak than it does about the true dead-
liness of COVID-19. One key reason: people with
milder versions of the illness are under represented
in official case counts, since they may not be sick
enough to seek medical attention or realize they
have anything more than a cold. That means the
total number of reported cases is very likely an un-
derestimate—and that the fatality rate is likely an
overestimate.
THE FACTS
1
2 3
BY JAMIE DUCHARME
AND ELIJAH WOLFSON
