Efeitos da pandemia de SARS-CoV-2 sobre a morbimortalidade por síndrome respiratória aguda grave em Belo Horizonte – 2013 a 2023

Abstract

Lower respiratory tract infections are the fifth leading cause of death in the world, being the main infectious cause. Infections with influenza and respiratory syncytial virus (RSV) were the most prominent because they caused more hospitalizations and deaths until 2019/2020 when a new strain of coronavirus called SARS-CoV-2 emerged. Objective: To describe the circulation of respiratory viruses associated with Severe Acute Respiratory Infection (SARI) in Belo Horizonte between 2013 and 2023, evaluating the effects of the pandemic on morbidity and mortality from influenza and RSV; and comparing sociodemographic characteristics, lethality and mortality rates of SARS-CoV-2 SARI cases, between 2020 and 2023. Methods: Ecologic study of SARI cases reported in Belo Horizonte between 2013 and 2023. Analysis of covid-19 cases comparing distribution by sex, age group and presence of risk conditions for worsening, as well as incidence, mortality and lethality rates between 2020 and 2023; and comparison of detection and lethality rates for influenza and RSV in three periods between 2013 and 2023 (pre-pandemic, pandemic with greater social isolation and after easing of control measures). Results: For SARS-CoV-2 SARI cases, there were higher incidence and mortality rates in 2021 (p < 0.05), for all age groups over 20 years old. There was a significant increase in the proportion of cases (38.9% to 50.2%) and deaths (16.3% to 26.1%) in patients under 60 years in 2021. In 2022, there was a reduction in the proportion of young adults (p < 0.05), but there was an increase in the proportion of people under 20 years, which was the only age group without a reduction in incidence and mortality from covid-19 this year. In 2023, there was a reduction in the incidence of SARI due to SARS-CoV-2 for all age groups (p < 0.05) and in mortality for those over 20 (p < 0.05). Covid-19 lethality rate has remained stable over the years (between 21.1% and 24.5%), including high social vulnerability patients. When analyzing the impact of the pandemic on the identification of influenza and RSV, a reduction in both viruses was observed in the period of greater social isolation, compared to the pre-pandemic period (Influenza reduced from 4.6% to 0.1%; VSR from 4.4% to 0.9%) (p<0.05). After the flexibility, influenza detection rates remained lower (1.5%), but there was an increase in RSV detection rates (5.9%) (p < 0.05). There was a significant reduction in RSV and influenza lethality (p < 0.05), but with high rates for patients over 60 years-old. Conclusion: The heterogeneity observed in morbidity and mortality rates, over the years, for different viruses and age groups, indicates the need for maintenance systematic surveillance. Similar fatality rates, especially in areas of high social vulnerability, indicate that Belo Horizonte's health system appears to be equitable. The increase in RSV circulation in SARI cases and its high lethality in the elderly, associated with the concentration of worse rates in the elderly population after the first moment of the pandemic, highlights the need to concentrate efforts on preventive measures, including vaccines, in this subgroup.