COVID-19 outbreak: a predictive mathematical study incorporating shedding effect

Abstract

In this paper, a modified SEIR epidemic model incorporating shedding effect is proposed to analyze transmission dynamics of the COVID-19 virus among different individuals’ classes. The direct impact of pathogen concentration over susceptible populations through the shedding of COVID-19 virus into the environment is investigated. Moreover, the threshold value of shedding parameters is computed which gives information about their significance in decreasing the impact of the disease. The basic reproduction number ( ) is calculated using the next-generation matrix method, taking shedding as a new infection. In the absence of disease, the condition for the equilibrium point to be locally and globally asymptotically stable with are established. It has been shown that the unique endemic equilibrium point is globally asymptotically stable under the condition . Bifurcation theory and center manifold theorem imply that the system exhibit backward bifurcation at . The sensitivity indices of are computed to investigate the robustness of model parameters. The numerical simulation is demonstrated to illustrate the results.

The Stability of Solutions of the Variable-Order Fractional Optimal Control Model for the COVID-19 Epidemic in Discrete Time

“…Suppose d k are real numbers for k = 0, 1, 2, • • • , 2n − 1 and d k are positive numbers. The Hurwitz matrix for Equation (7) is defined as a square matrix of size n × n as follows:…”

“…However, SADS-CoV (Swine acute diarrhea syndrome coronavirus), which utilizes swines as intermediate carriers, does not induce infectious symptoms in humans. While both HCoV-OC43 and HCoV-HKU1 belong to the β-coronavirus category, they typically pose no serious threat to humans [7]. However, the perception of highly pathogenic coronaviruses changed significantly following the outbreaks of SARS-CoV (severe acute respiratory syndrome coronavirus) in 2003 and MERS-CoV (Middle East respiratory syndrome coronavirus) in 2012 [7].…”