Clinical Course of SARS-CoV Influenza Virus and RSV Infections in Children during the Pandemic: Can ILI and SARI Definitions Predict Clinical Diagnosis

Abstract

Introduction: In this study, we aimed to evaluate cases of respiratory tract infections caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), respiratory syncytial virus (RSV), and influenza viruses in children aged 2-5 years during the pandemic, and to assess the compatibility of these cases with the definitions of influenza-like illness (ILI) and severe acute respiratory infections (SARI). Materials and Methods: A total of 87 patients under the age of five, presented to pediatric outpatient clinics with respiratory tract infection complaints between December 15, 2022, and March 15, 2023, and underwent respiratory polymerase chain reaction (PCR) testing on nasopharyngeal swab samples, were included in the study. All data were retrieved from hospital records. Results: The mean age of the patients was 38.3 +/- 10.4 months (range= 25-60 months), and 48 (55.2%) were male. Of the patients admitted with respiratory tract infection, 13 (14.9%) were found to be RSV positive, 18 (20.7%) were influenza virus positive, and 12 (13.8%) were SARS-CoV-2 PCR positive. The rate of patients with runny nose (94.4%) and conjunctivitis (27.8%) in the influenza virus positive group, and dyspnea (61.5%), retraction (53.8%), rhonchi (46%), pulmonary findings on radiography (69.2%) and reticular pattern (14%) in the RSV positive group were significantly higher than the other groups. The sensitivity and specificity of the ILI definition for detecting influenza positivity were determined to be 100% and 46.2%, respectively. However, these results indicate that the ILI and/or SARI definitions were not effective in identifying RSV infection or novel coronavirus diseases-2019 (COVID-19) in children. Conclusion: Our study demonstrated that RSV and influenza virus infections decreased in children during the pandemic. Notably, in the younger age group, respiratory symptoms were predominant in the diagnosis of RSV, while runny nose and conjunctivitis were key indicators for the diagnosis of influenza. However, no distinct distinguishing findings were found for COVID-19. Moreover, to the best of our knowledge, this study is the first in the literature to demonstrate that while the ILI definition is sufficient to identify influenza and similar infections, it is inadequate for identifying RSV infection and COVID-19.