COVID-19 Propagation Prediction and Assessment Method with Imported Cases and Infection Generations: Shanxi Province as a Case

Abstract When everyone focuses on 2019 coronavirus disease (COVID-19) in Hubei province, the epidemic in other province cannot be ignored, which also has an impact on the epidemic in the whole country. The most distinctive epidemic characteristic in all regions except Wuhan is that the most of confirmed cases are imported cases from Wuhan, and the propagation chain is relatively clear. Based on detailed contact tracing information of confirmed cases, combined with first-order outbreak response measures, we establish a disease transmission dynamical model to describe the infection propagation chain among the human population. Using Shanxi province as a case, modeling results indicate that the epidemic peak in Shanxi province occurred in February 2. In addition, our model suggests that according to the current development trend, COVID-19 will disappear in February with the final epidemic number of approximately 175 cases. It is verified that the most effective outbreak control measures in Shanxi include home isolation of people, surveillance and isolation of second-generation cases, contact tracing and management of contacts. With the end of the holiday, if the average number of contacts per person per day is less than 6 , it has little impact on the incidence of COVID-19, and even if third- and fourth-generation cases occur, the epidemic will be under control, no later than late March with a finial outbreak size of 220 cases. However, if the average number of contacts per person per day is greater than 6, the number of COVID-19 cases will continue to be reported resulting in another epidemic peak. Through the forecast and evaluation of COVID-19 in Shanxi, it is verified that the model with infection generations is more accurate to describe the spread mode and can be extended to regions with imported cases.