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 2020-05-15 365,638 281,260 522,340
China 2020-05-15 84,092 84,038 120,131
France 2020-05-15 183,863 179,630 262,662
Germany 2020-05-15 180,660 175,233 258,085
Iran 2020-05-15 132,710 116,635 189,585
Italy 2020-05-15 232,235 223,885 331,764
Japan 2020-05-15 16,937 16,203 24,196
Portugal 2020-05-15 30,473 28,583 43,532
Singapore 2020-05-15 34,143 26,891 48,776
South Korea 2020-05-15 11,242 11,037 16,059
Spain 2020-05-15 235,768 230,183 336,812
United Kingdom 2020-05-15 267,666 238,004 382,381
United States 2020-05-15 1,651,352 1,442,824 2,359,074

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 2020-05-15 220,291 365,638
China 2020-05-15 84,038 84,092
France 2020-05-15 179,630 183,863
Germany 2020-05-15 175,233 180,660
Iran 2020-05-15 116,635 132,710
Italy 2020-05-15 223,885 232,235
Japan 2020-05-15 16,203 16,937
Portugal 2020-05-15 28,583 30,473
Singapore 2020-05-15 26,891 34,143
South Korea 2020-05-15 11,037 11,242
Spain 2020-05-15 230,183 235,768
United Kingdom 2020-05-15 238,004 267,666
United States 2020-05-15 1,442,824 1,651,352

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