Simulating the infected population and spread trend of 2019-nCov under different policy by EIR model

Hao Xiong; Huili Yan

We expect that the epidemic of Corona virus in China will exist until May 2020. So, we set the simulation period is from Dec. 1, 2019 (t=1) to Apr. 30, 2020 (t=167). The baseline scenario is with quarantine rate 100% and action starting date Jan. 23, 2020 (t=69). Given different quarantine rates and action starting date, the main results are reported as follows. Figure 2 showed the results of when quarantined rate is zero, that is k=5, which also could be taken as the scenario of no prevention measures are taken all the way. In this scenario, the number of the exposed individuals and identified individuals are presented as Exponential growth. At the end of April, there would be 740508835 individuals identified. (t=167) and the trajectory of official data from Jan. 23, 2020 (t=66) to Feb. 7, 2020 (t=84). In figure 3 , the green solid line is the trajectory of official data from Jan. 23, 2020 (t=66) to Feb. 7, 2020 (t=84), the red dashed line is the simulated curve of identified individuals. The second half of the trajectory of official data are well fitted by the simulation of the baseline scenario. From the simulation of baseline scenario, the estimation of the first half of the epidemic spreading from Jan. 20 (t=66) to Feb.7 (t=84) is higher than the official data. This could be explained by that, at the first stage, as the absence of the knowledge of the novel virus, the diagnoses are impossible to identify all the exposed individuals in time. So, it is naturally the confirmed number would be less than the actual exposed individuals at the beginning period of epidemic spreading.