Aspectos epidemiológicos e fingerprinting da microbiota do trato respiratório superior: estudo comparativo entre indivíduos comunitários ou hospitalizados com COVID-19 e pacientes comunitários com SRAG por outras etiologias

Abstract

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had a significant global impact, with more than 761 million infections and 6.7 million deaths worldwide. In Brazil, the health and hospital crisis resulted in the biggest collapse in the country's history. This has affected the prevalence of other respiratory viruses, but a diverse group of viruses, such as rhinoviruses, adenoviruses, parainfluenza, metapneumoviruses, and influenza, still cause a large number of respiratory illnesses. They continue to be a leading cause of acute respiratory infections, not related to COVID-19. The diagnosis of viral respiratory infections can be based on clinical symptoms or the etiological agent. Knowledge about the respiratory microbiome is an area of growing interest in pulmonary medicine, as its diversity and balance have a direct impact on health and disease. Factors such as type of birth, age, sex, genetic conditions, social behavior and diet play an important role in the composition of the microbiota. The immune response to infection is affected by several factors, including intrinsic and extrinsic biological conditions of the host. Studies show significant sex differences in immune response, with women generally having stronger responses, developing more robust vaccine responses, and surviving acute infections better. This study analyzed the structure of the microbiota of respiratory samples from patients hospitalized due to COVID-19, patients with flu syndrome from other causes and the influence of sociodemographic and clinical characteristics. The sample included 118 individuals of both sexes and different ages. The results revealed that the group of hospitalized COVID-19 patients (G3) had the lowest percentage of flu vaccination and more comorbidities, while the group with flu syndrome of other etiologies (G1) and the group with community COVID-19 (G2) had better immunization rates. G1 had the largest number of healthy individuals. Symptoms varied, with G1 predominantly having respiratory symptoms, while G2 and G3 had both respiratory and non-respiratory symptoms, with G2 being more affected. The fingerprint results grouped the patients into two clusters: C1, mostly composed of hospitalized, elderly and less immunized individuals; and C2, which included young individuals with and without COVID-19, who were more immunized. In summary, this study highlighted the importance of considering not only SARS-CoV-2 but other respiratory viruses in the diagnosis and treatment of respiratory infections. Furthermore, it showed how the respiratory microbiome and sociodemographic and clinical factors influence the immune response and the severity of infections. These discoveries can promote more effective strategies for preventing and treating respiratory diseases, but it is essential to carry out more research to deepen the understanding of these mechanisms and improve the clinical management of these diseases.