Modeling the Effect of Asymptomatic Cases, Social Distancing, and Lockdowns in the First and Second waves of the COVID-19 Pandemic: A Case Study of Italy

Abstract

The SEIR model of COVID-19 is developed to investigate the roles of physical distancing, lockdowns, and asymptomatic cases in Italy. In doing so, two types of policies including behavioral measures and lockdown measures are embedded in the model. Compared with existing models, the model successfully reproduces similar multiple observed outputs such as infected and recovered patients in Italy by July 2020. This study concludes that the first policy is important once the number of infected cases is relatively low. However, once the number of infected cases is too high, so the society cannot identify infected and disinfected people, the second policy must be applied soon. It is thus this study suggests that relaxed lockdowns lead to the second wave of the COVID-19 around the world. It is hoped that the model can enhance our understanding of the roles of behavioral measures, lockdowns, and undocumented cases, so-called asymptomatic cases, on the COVID-19 flow. Doi: 10.28991/SciMedJ-2021-0303-8 Full Text: PDF

Exploring the Impacts of COVID-19 on Coastal Tourism to Inform Recovery Strategies in Nelson Mandela Bay, South Africa

“…Thereafter, the infection dynamics are formulated such that the Susceptible Population (60 million persons) flows into the Exposed Population depending on the infectivity of the virus, which can depend on the variant of the virus. In the model, the infectivity is estimated to be 0.0125 dmnl, so as to obtain a reproduction factor between 3 and 5 dmnl, depending on the number of social contacts (~14 persons/person/day) and duration of the infection (~14 days) [23]. After an incubation delay of approximately ~5 days [8,10], the exposed population then becomes either symptomatically or asymptomatically infectious.…”