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 2020-05-06 211,666 162,820 302,380
China 2020-05-06 83,992 83,970 119,989
France 2020-05-06 186,171 174,224 265,958
Germany 2020-05-06 174,723 168,162 249,604
Iran 2020-05-06 112,834 101,650 161,191
Italy 2020-05-06 225,062 214,457 321,518
Japan 2020-05-06 16,706 15,253 23,865
Portugal 2020-05-06 28,274 26,182 40,392
Singapore 2020-05-06 26,630 20,485 38,043
South Korea 2020-05-06 10,844 10,810 15,492
Spain 2020-05-06 227,989 220,325 325,699
United Kingdom 2020-05-06 245,512 202,359 350,732
United States 2020-05-06 1,443,505 1,228,603 2,062,150

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 2020-05-06 126,611 211,666
China 2020-05-06 83,970 83,992
France 2020-05-06 174,224 186,171
Germany 2020-05-06 168,162 174,723
Iran 2020-05-06 101,650 112,834
Italy 2020-05-06 214,457 225,062
Japan 2020-05-06 15,253 16,706
Portugal 2020-05-06 26,182 28,274
Singapore 2020-05-06 20,198 26,630
South Korea 2020-05-06 10,810 10,844
Spain 2020-05-06 220,325 227,989
United Kingdom 2020-05-06 202,359 245,512
United States 2020-05-06 1,228,603 1,443,505

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