SimCOVID: An Open-Source Simulink-Based Program for Simulating the COVID-19 Epidemic

Ismael Khorshed Abdulrahman

is the (which was not peer-reviewed) The copyright holder for this preprint . https://doi.org/10.1101/2020.04.13.20063354 doi: medRxiv preprint Figure 4 shows the final values of the optimized parameters for the outbreak of China and Italy. We can see a reproductive ratio of more than one (a sign of pandemic) from the beginning of the outbreak until around the inflection point of the curve. The numerical results obtained from this simulation are plotted and shown in Fig. 5a for the China outbreak and Fig.5b -c for the Italy outbreak. The daily infectious state variable is plotted on the left y-axis whereas the cumulative infectious variable is plotted on the right y-axis. Note that the cumulative infectious is the sum of the daily infectious values which can be modeled in Simulink using an integrator. As mentioned in [6] , the sudden jump in the curve is due to the way the data was collected and the diagnosis techniques which is not interpreted by a natural variation of a pandemic. Therefore, the program tries to change the parameters so that the simulated cumulative cases are close to the actual recorded ones. There is a good matching between the two cumulative plots although the daily infectious plots show some mismatch at peak time. For the Italy outbreak, there is a quite matching between the simulated and the reported cases as there is no change in the calculation method. In addition, we need to estimate the final size of the epidemic. The program estimates the rest of the simulation and the results show that the total cases for Italy outbreak could reach 230,000-330,000 cases at the end of July 2020 with a ±10 error in the infection rate. This estimation is based on the given data from the beginning of the reported cases until the date April 09, 2020. For the China outbreak, it is enough to take data for simulation until the settling time of the curve which is around middle of March 2020. Fig. 5b -c show the daily infectious and cumulative infectious plots for the Italy outbreak with the estimated final range colored in grey [17] .