Warning: This analysis contains the results of a predictive model. There are a number of assumptions made which include some speculation. Furthermore, this analysis was not prepared or reviewed by an Epidimiologist. Therefore, the assumptions and methods presented should be scrutinized carefully before arriving at any conclusions.

Estimated Infected Population By Country

with respect to days since outbreak

Tip: Click (Shift+ for multiple) on countries in the legend to filter the visualization.

Latest Country Estimates

Date Estimated Infected Lower Bound Estimates Upper Bound Estimates
Country
Brazil 2020-08-06 3,301,753 2,912,212 4,716,789
China 2020-08-06 89,417 88,460 127,739
France 2020-08-06 243,993 231,310 348,561
Germany 2020-08-06 222,868 215,039 318,382
Iran 2020-08-06 342,498 320,117 489,282
Italy 2020-08-06 251,486 249,204 359,266
Japan 2020-08-06 56,107 44,167 80,153
Portugal 2020-08-06 53,276 52,061 76,109
Singapore 2020-08-06 58,172 54,555 83,103
South Korea 2020-08-06 14,782 14,519 21,117
Spain 2020-08-06 356,921 309,855 509,887
United Kingdom 2020-08-06 316,879 309,796 452,685
United States 2020-08-06 5,341,982 4,883,582 7,631,403

Infected vs. number of confirmed cases

Allows you to compare how countries have been tracking the true number of infected people. The smaller deviation from the dashed line (45 degree line) the better job at tracking the true number of infected people.

Tip: Click (Shift+ for multiple) on countries in the legend to filter the visualization.

Latest Observed vs. Estimate of Infected Cases

Date Observed Cases Estimated Infected
Country
Brazil 2020-08-06 2,912,212 3,301,753
China 2020-08-06 88,460 89,417
France 2020-08-06 231,310 243,993
Germany 2020-08-06 215,039 222,868
Iran 2020-08-06 320,117 342,498
Italy 2020-08-06 249,204 251,486
Japan 2020-08-06 44,167 56,107
Portugal 2020-08-06 52,061 53,276
Singapore 2020-08-06 54,555 58,172
South Korea 2020-08-06 14,519 14,782
Spain 2020-08-06 309,855 356,921
United Kingdom 2020-08-06 309,796 316,879
United States 2020-08-06 4,883,582 5,341,982

Methodology

We argue that the number of infected in the past can be inferred using today's number of deaths and average fatality rate from confirmed cases in the following way:

$$I_{t-j} = \frac{D_t}{{CFR}_t}$$

where $I_t$ = number of infected, $D_t$ = number of deaths, and ${CFR}_t $ = case fatality rate = $\frac{D}{C}$. The $j$ depends on the average number of days that covid patients die after having the first symptoms.

Assumption 1: The case fatality rate is a good proxy for the fatality rate of the infected population

Then, in order to estimate the current number of infected $I_t$ we need to estimate its growth rate from $t-j$ to $t$.

$$I_t = (1+\hat{g})^j I_{t-j}$$

Assumption 2: The growth rate of infected $\hat{g}$ is an unbiased estimate of $g$ .

For now we estimate $g$ using the average growth rate since having the first infected person.

Assumption 3: It takes on average 8 days to die after having the first symptoms.

This analysis was conducted by Joao B. Duarte. Relevant sources are listed below:

  1. 2019 Novel Coronavirus COVID-19 (2019-nCoV) Data Repository by Johns Hopkins CSSE GitHub repository.

  2. Feenstra, Robert C., Robert Inklaar and Marcel P. Timmer (2015), "The Next Generation of the Penn World Table" American Economic Review, 105(10), 3150-3182