Infectious Disease Transmission In A Modified SEIRS model

TL;DR

This paper introduces a modified SEIRS model called SEIRSD that incorporates reverse transmission from exposed to susceptible and accounts for infection-related mortality, providing insights into disease spread dynamics relevant to COVID-19 variants.

Contribution

The paper proposes a novel SEIRSD model with reverse transmission and mortality, enhancing the realism of infectious disease modeling compared to traditional SEIRS models.

Findings

Reverse transmission significantly affects infection peak height.

Including mortality alters disease progression predictions.

Model relevance to COVID-19 variant surges.

Abstract

Compartmental models like the Susceptible-Infected-Recovered (SIR)\cite{Kermack1927} and its extensions such as the Susceptible-Exposed-Infected-Recovered (SEIRS)\cite{Ottar2020,Ignazio2021,Grimm2021,Paoluzzi2021} are commonly used to model the spread of infectious diseases. We propose here, a modified SEIRS, namely, an SEIRSD model which comprises of (i) a reverse transmission from exposed to susceptible compartment to account for the probabilistic character of disease transmission seen in nature, and (ii) inclusion of mortality caused by infection in addition to death by other causes. We observed that, a reverse flow from exposed to susceptible class, has a significant impact on the height of infection peaks and their time of occurrence. In view of the recent surges of Covid-19 variants, this study is most relevant.