Caracterização das estratégias diagnósticas adotadas no período de pandemia por SARS-CoV-2: uma perspectiva epidemiológica

Abstract

The emergence of the SARS-CoV-2 virus in late 2019 triggered a global health crisis, leading to the World Health Organization (WHO) declaring a pandemic in March 2020. The rapid spread of the virus and the emergence of new variants underscored the importance of diagnosis as a crucial pillar for the control and monitoring of the virus's spread. Additionally, it became essential for guiding diagnostic practices, isolation strategies, healthcare delivery, and biosafety measures. Throughout the pandemic, official documents were issued by public health authorities, accumulating information and guidance to steer policymakers and healthcare professionals in the use of diagnostic tests in line with the evolving pandemic. This study aims to characterize the implementation of diagnostic strategies for COVID-19, describing key measures and their temporal alignment with the emergence of variants in the state of Rio Grande do Sul (RS). The study also sought to estimate the proportion of correct diagnoses from the tests involved in these strategies, along with characterizing the population undergoing diagnostic testing during predefined periods. The adopted methodology for data collection encompassed information from the e-SUS databases from 2020 to 2023. Testing strategies were compiled from 16 informative notes issued by the RS government between 2020 and 2022. The analysis of variant prevalences in RS was conducted using the GISAID platform, subsequently evaluated on the Nextclade platform. The proportion of correct diagnoses was calculated based on the book Epidemiology: Theory and Practice. Five testing strategies were identified and described, correlated with the periods in which they were implemented. Regarding the characterization of the sample population, an average age of 38.8 years was observed, with a female predominance. The predominant variants in the investigated periods included B.1.1.33 (periods 1 and 2), Zeta (P.2) (period 3), Gamma (P.1) (period 4), and Omicron, including its subvariants (period 5). Concerning the proportion of correct diagnoses from the tests, a value of 98.5% was found for the TRAc and 96.9% for the TRAg, respectively. This study provides a comprehensive insight into the adopted diagnostic strategies, their temporal context in relation to variants, and the accuracy of the tests used, contributing to a broader understanding of diagnostic dynamics during the evolution of the COVID-19 pandemic in the state of RS.