Using the SIRD model to characterize the COVID-19 spreading in the states of Paraná, Rio Grande do Sul, and Santa Catarina

Abstract

In this work, we analyzed the data for the cumulative number of confirmed cases and deaths caused by COVID-19 for Paraná (PR), Rio Grande do Sul (RS), and Santa Catarina (SC). The key aim of this study is to understand the features of the COVID-19 spreading in the South Region of Brazil by estimating the Effective Reproduction Number (ERN) R_e for each state using the SIRD (Susceptibles-Infectious-Recovered-Dead) model. We show that this model, despite its simplicity, describes trusty the real data and allows us to project the trends of the epidemic in each locality. After adjusting the model to the real data and obtaining the current ERN, we simulated strategies to decrease gradually the value of R_e and to reach the flattening of the epidemic curve. Our results suggest that, until June 6^th, 2020, SC was the only state for which R_e < 1, which indicates that the number of newly infected people might decrease if this scenario remains unchanged. On the other hand, PR and RS show R_e > 1, and the increase in the number of newly infected people might continue for some weeks if some containment measures are not taken.