Objective: To establish a SEIR epidemic dynamics model that can be used to evaluate the COVID-19 epidemic, and to predict and evaluate the COVID-19 epidemic in Hubei province using the proposed model.
Methods: COVID-19 SEIR transmission dynamics model was established, which took transmission ability in latent period and tracking quarantine interventions into consideration. Based on the epidemic data of Hubei province from January 23, 2020 to February 24, 2020, the parameters of the newly established modified SEIR model were fitted. By using Euler integral algorithm to solve the modified SEIR dynamics model, the epidemic situation in Hubei province was analyzed, and the impact of prevention and control measures such as quarantine and centralized treatment on the epidemic development was discussed.
Results: The theoretical estimation of the epidemic situation by the modified SEIR epidemic dynamics model is in good agreement with the actual situation in Hubei province. Theoretical analysis showed that prevention and control quarantine and medical follow-up quarantine played an important inhibitory effect on the outbreak of the epidemic.The centralized treatment played a key role in the rapid decline in the number of infected people. In addition, it is suggested that individuals should improve their prevention awareness and take strict self-protection measures to curb the increase in infected people.
Conclusions: The modified SEIR model is reliable in the evaluation of COVID-19 epidemic in Hubei province, which provides a theoretical reference for the decision-making of epidemic interventions.
目的: 建立可用于2019冠状病毒病（COVID-19）疫情评估的SEIR传染病动力学模型，并对湖北省COVID-19疫情进行预测和评估。
方法: 考虑COVID-19潜伏期患者不易被有效隔离，且具有较强的传染能力，建立了联合考虑潜伏期传播能力和追踪隔离干预措施的COVID-19 SEIR传染病动力学模型。以2020年1月23日至2月24日的湖北省疫情数据为依据，拟合得到了新建立的修正SEIR模型的动力学参数。通过欧拉数值方法实现修正SEIR传染病动力学模型的求解，对湖北省疫情进行分析，评估防控隔离和集中收治等措施对疫情发展的影响。
结果: 修正的SEIR传染病动力学模型对疫情的理论估计与湖北省疫情的实际情况较为符合。模型理论分析表明，防控隔离和医学追踪隔离等措施对疫情大面积传播有重要抑制作用；集中接收、分层治疗等重要措施对感染人数峰值的迅速回落起到了关键作用；此外，个人提高防范意识，采取严格自我防护措施，遏制了感染人数的新增。
结论: 修正的SEIR传染病动力学模型可用于COVID-19传播态势分析，以便为制订未来的疫情干预决策提供一定的理论支持。