SIR model with exposure rate for the study of the projection of COVID-19 cases in Sergipe

Abstract

In this work, we used two models to study the behavior of the epidemic curve of COVID-19 in Sergipe between March 14, 2020 and May 2, 2020: conventional SIR model and a variant thereof, which incorporates the number of individuals more exposed to contagion than the rest of the population. We built this variant of the SIR model based on another model proposed to describe the epidemic outbreak of COVID-19 in South Korea and Portugal. In the SIR model with exposure proposed here, we introduced an exposure factor, called β1 / β2, which allows us to describe the influence of factors, such as social withdrawal, on the spread of the disease. In our work, to compare the data obtained through simulation and the number of cases officially registered in Sergipe; we consider that there are between three and nine real cases for each officially registered case, that there are individuals more likely to be infected than others, here exposed individuals, and that the number of reproduction varies over time, growing exponentially in the beginning of the outbreak. epidemic. The simulation results show that the contagion rate is in the range of 2.9 or higher, a region in which there is greater agreement between the model and the data collected.