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Cleo Anastassopoulou, Lucia Russo, Athanasios Tsakris, Constantinos Siettos |

- 2020-07-12

- 6 M

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Since the first suspected case of coronavirus disease-2019 (COVID-19) on December 1st,

2019, in Wuhan, Hubei Province, China, a total of 40,235 confirmed cases and 909 deaths

have been reported in China up to February 10, 2020, evoking fear locally and

internationally. Here, based on the publicly available epidemiological data for Hubei, China

from January 11 to February 10, 2020, we provide estimates of the main epidemiological

parameters. In particular, we provide an estimation of the case fatality and case recovery

ratios, along with their 90% confidence intervals as the outbreak evolves.

On the basis of a Susceptible-Infectious-Recovered-Dead (SIDR) model, we provide

estimations of the basic reproduction number (R?), and the per day infection mortality and

recovery rates. By calibrating the parameters of the SIRD model to the reported data, we

also attempt to forecast the evolution of the outbreak at the epicenter three weeks ahead,

i.e. until February 29. As the number of infected individuals, especially of those with

asymptomatic or mild courses, is suspected to be much higher than the official numbers,

which can be considered only as a subset of the actual numbers of infected and recovered

cases in the total population, we have repeated the calculations under a second scenario

that considers twenty times the number of confirmed infected cases and forty times the

number of recovered, leaving the number of deaths unchanged. Based on the reported

data, the expected value of R? as computed considering the period from the 11th of

January until the 18th of January, using the official counts of confirmed cases was found

to be 4.6, while the one computed under the second scenario was found to be 3.2. Thus,

based on the SIRD simulations, the estimated average value of R? was found to be 2.6

based on confirmed cases and 2 based on the second scenario. Our forecasting flashes a

note of caution for the presently unfolding outbreak in China. Based on the official counts

for confirmed cases, the simulations suggest that the cumulative number of infected could

reach 180,000 (with a lower bound of 45,000) by February 29. Regarding the number of

deaths, simulations forecast that on the basis of the up to the 10th of February reported

data, the death toll might exceed 2,700 (as a lower bound) by February 29. Our analysis

further reveals a significant decline of the case fatality ratio from January 26 to which

various factors may have contributed, such as the severe control measures taken in Hubei,

China (e.g. quarantine and hospitalization of infected individuals), but mainly because of

the fact that the actual cumulative numbers of infected and recovered cases in the

population most likely are much higher than the reported ones. Thus, in a scenario where

we have taken twenty times the confirmed number of infected and forty times the

confirmed number of recovered cases, the case fatality ratio is around 0.15% in the total

population. Importantly, based on this scenario, simulations suggest a slow down of the

outbreak in Hubei at the end of February.

1 ڷγ̷

1. ڷγ̷-19(Covid-19) 7

2. ڷγ̷ з Ư 9

3. ڷγ̷ ̰ 11

4. ڷγ̷ (Covid-19 Organization) 13

5. ڷγ19: ȯ濡 ĥ? 19

6. ġ(Therapeutical Method) 22

2

Data-based analysis, modelling and forecasting of the COVID-19

outbreak

1. Introduction 24

2. Methodology 25

3. Estimation of the basic reproduction number from the SIRD model 26

4. Estimation of the effective SIRD model parameters 27

4. Results 28

5. Discussion 39

6. Conclusions 42

7. References 42