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 2020-05-17 382,352 294,117 546,218
China 2020-05-17 84,114 84,054 120,163
France 2020-05-17 182,746 179,693 261,066
Germany 2020-05-17 180,993 176,369 258,561
Iran 2020-05-17 136,524 120,198 195,034
Italy 2020-05-17 232,235 225,435 331,764
Japan 2020-05-17 16,767 16,285 23,952
Portugal 2020-05-17 30,924 29,036 44,178
Singapore 2020-05-17 34,224 28,038 48,892
South Korea 2020-05-17 11,214 11,065 16,021
Spain 2020-05-17 234,761 230,698 335,372
United Kingdom 2020-05-17 275,379 244,995 393,399
United States 2020-05-17 1,698,066 1,486,757 2,425,809

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 2020-05-17 241,080 382,352
China 2020-05-17 84,054 84,114
France 2020-05-17 179,693 182,746
Germany 2020-05-17 176,369 180,993
Iran 2020-05-17 120,198 136,524
Italy 2020-05-17 225,435 232,235
Japan 2020-05-17 16,285 16,767
Portugal 2020-05-17 29,036 30,924
Singapore 2020-05-17 28,038 34,224
South Korea 2020-05-17 11,065 11,214
Spain 2020-05-17 230,698 234,761
United Kingdom 2020-05-17 244,995 275,379
United States 2020-05-17 1,486,757 1,698,066

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