Saha Sangeeta, Samanta G P, Nieto Juan J
Department of Mathematics, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, 711103 India.
Instituto de Matematicas, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Nonlinear Dyn. 2020;102(1):455-487. doi: 10.1007/s11071-020-05896-w. Epub 2020 Aug 26.
COVID-19 has spread around the world since December 2019, creating one of the greatest pandemics ever witnessed. According to the current reports, this is a situation when people need to be more careful and take the precaution measures more seriously, unless the condition may become even worse. Maintaining social distances and proper hygiene, staying at isolation or adopting the self-quarantine method are some of the common practices that people should use to avoid the infection. And the growing information regarding COVID-19 and its symptoms help the people to take proper precautions. In this present study, we consider an SEIRS epidemiological model on COVID-19 transmission which accounts for the effect of an individual's behavioural response due to the information regarding proper precautions. Our results indicate that if people respond to the growing information regarding awareness at a higher rate and start to take the protective measures, then the infected population decreases significantly. The disease fatality can be controlled only if a large proportion of individuals become immune, either by natural immunity or by a proper vaccine. In order to apply the latter option, we need to wait until a safe and proper vaccine is developed and it is a time-taking process. Hence, in the latter part of the work, an optimal control problem is considered by implementing control strategies to reduce the disease burden. Numerical figures show that the control denoting behavioural response works with higher intensity immediately after implementation and then gradually decreases with time. Further, the control policy denoting hospitalisation of infected individuals works with its maximum intensity for quite a long time period following a sudden decrease. As, the implementation of the control strategies reduce the infected population and increase the recovered population, so, it may help to reduce the disease transmission at this current epidemic situation.
自2019年12月以来，新冠病毒已在全球传播，造成了有史以来最严重的大流行之一。根据目前的报告，在这种情况下，人们需要更加小心，更认真地采取预防措施，否则情况可能会变得更糟。保持社交距离和良好的卫生习惯、居家隔离或采取自我隔离方法是人们应采用的一些常见做法，以避免感染。关于新冠病毒及其症状的信息不断增加，有助于人们采取适当的预防措施。在本研究中，我们考虑了一个关于新冠病毒传播的SEIRS流行病学模型，该模型考虑了由于有关适当预防措施的信息而导致的个体行为反应的影响。我们的结果表明，如果人们以更高的速度对不断增加的有关意识的信息做出反应，并开始采取保护措施，那么感染人群将显著减少。只有当很大一部分人通过自然免疫或适当的疫苗获得免疫时，疾病死亡率才能得到控制。为了采用后一种选择，我们需要等到开发出安全、合适的疫苗，而这是一个耗时的过程。因此，在工作的后半部分，我们通过实施控制策略来减轻疾病负担，考虑了一个最优控制问题。数值结果表明，表示行为反应的控制措施在实施后立即具有较高的强度，然后随着时间的推移逐渐减弱。此外，表示感染个体住院治疗的控制策略在突然下降后很长一段时间内都具有最大强度。由于控制策略的实施减少了感染人群，增加了康复人群，因此，它可能有助于在当前疫情形势下减少疾病传播。
