Deng Yang, Zhao Yi
School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055 China.
Nonlinear Dyn. 2022;110(4):3893-3919. doi: 10.1007/s11071-022-07777-w. Epub 2022 Aug 27.
The realistic assessments of public health intervention strategies are of great significance to effectively combat the COVID-19 epidemic and the formation of intervention policy. In this paper, an extended COVID-19 epidemic model is devised to assess the severity of the pandemic and explore effective control strategies. The model is characterized by ordinary differential equations with seven-state variables, and it incorporates some parameters associated with the interventions (i.e., media publicity, home isolation, vaccination and face-mask wearing) to investigate the impacts of these interventions on the spread of the COVID-19 epidemic. Some dynamic behaviors of the model, such as forward and backward bifurcation, are analyzed. Specifically, we calibrate the model parameters using actual COVID-19 infected data in Brazil by Markov Chain Monte Carlo algorithm such that we can study the effects of interventions on a practical case. Through a comprehensive exploration of model design and analysis, model calibration, sensitivity analysis, implementation of optimal control problems and cost-effectiveness analysis, the rationality of our model is verified, and the effective strategies to combat the epidemic in Brazil are revealed. The results show that the asymptomatic infected individuals are the main drivers of COVID-19 transmission, and rapid detection of asymptomatic infections is critical to combat the COVID-19 epidemic in Brazil. Interestingly, the effect of the vaccination rate associated with pharmaceutical intervention on the basic reproduction number is much lower than that of non-pharmaceutical interventions (NPIs). Our study also highlights the importance of media publicity. To reduce the infected individuals, the multi-pronged NPIs have considerable positive effects on controlling the outbreak of COVID-19. The infections are significantly decreased by the early implementation of media publicity complemented with home isolation and face-mask wearing strategy. When the cost of implementation is taken into account, the early implementation of media publicity complemented with a face-mask wearing strategy can significantly mitigate the second wave of the epidemic in Brazil. These results provide some management implications for controlling COVID-19.
对公共卫生干预策略进行现实评估对于有效抗击新冠疫情及制定干预政策具有重要意义。本文设计了一个扩展的新冠疫情模型，以评估疫情的严重程度并探索有效的控制策略。该模型由具有七个状态变量的常微分方程表征，并纳入了一些与干预措施（即媒体宣传、居家隔离、疫苗接种和佩戴口罩）相关的参数，以研究这些干预措施对新冠疫情传播的影响。分析了该模型的一些动态行为，如前向和后向分岔。具体而言，我们使用马尔可夫链蒙特卡罗算法，根据巴西实际的新冠感染数据对模型参数进行校准，以便能够研究干预措施在实际案例中的效果。通过对模型设计与分析、模型校准、敏感性分析、最优控制问题的实施以及成本效益分析的全面探索，验证了我们模型的合理性，并揭示了巴西抗击疫情的有效策略。结果表明，无症状感染者是新冠传播的主要驱动因素，快速检测无症状感染对于巴西抗击新冠疫情至关重要。有趣的是，与药物干预相关的疫苗接种率对基本再生数的影响远低于非药物干预（NPIs）。我们的研究还强调了媒体宣传的重要性。为了减少感染者，多管齐下的非药物干预措施对控制新冠疫情的爆发具有相当大的积极作用。通过早期实施媒体宣传并辅以居家隔离和佩戴口罩策略，感染人数显著减少。考虑到实施成本，早期实施媒体宣传并辅以佩戴口罩策略可以显著减轻巴西疫情的第二波高峰。这些结果为控制新冠疫情提供了一些管理启示。
