Epidemiological evolution of COVID-19: a three-year perspective on coping with the pandemic in the States of Rio Grande do Sul and Paraná, Southern Region of Brazil

Introduction: The novel Coronavirus disease (COVID-19) is caused by SARS-CoV-2 and represents the agent responsible for a respiratory and metabolic disease with a high fatality rate, remaining a public health problem to this day. There has been an exacerbation of social inequalities experienced in Brazil and worldwide. Notably, the absence of a consolidated and universal healthcare system has contributed to the increased inequalities and survival opportunities for those affected by SARS-CoV-2 infection and manifestation of COVID-19. The southern region has become the second region with the highest number of cases in Brazil. Objective: To avaluate the epidemiological outcomes of incidence, lethality, and mortality among the states of Rio Grande do Sul and Paraná in the southern region of Brazil. Methods: An ecological time-series study was conducted using official secondary data on COVID-19 cases and deaths publicly disclosed by the health departments of the states of Rio Grande do Sul and Paraná. Time series were constructed applying the Prais-Winsten regression model. Statistical analyses were performed using STATA 14.0 software. Results: It was observed that for the state of Rio Grande do Sul, the trends regarding incidence were increasing in 2020 and decreasing in 2021 (p<0.05). Regarding mortality, it increased in 2020 and decreased in 2021 and 2022 (p<0.05). When assessing lethality, a decreasing trend was observed for the entire period (p<0.05). In relation to Paraná, incidence increased in 2020 and over the entire period, while it decreased in 2021 and 2022 (p<0.05). Mortality was stationary in 2020 and decreased in 2021 and 2022 (p<0.05). Conclusion: The COVID-19 pandemic is a serious public health problem in the states of Paraná and Rio Grande do Sul. Paraná presented a more severe epidemiological outcome compared to Rio Grande do Sul.