Severe viral lower respiratory tract infections in Brazilian children: Clinical features of a national cohort.

ABSTRACT

BACKGROUND: The accurate etiological diagnosis of lower respiratory tract infections (LRTI) is essential for their effective clinical management. The extensive use of molecular methods during the COVID-19 pandemic has enabled massive data acquisition on viral lower respiratory tract infections. The current study aims to identify clinical features associated with eight viral agents among children presenting severe LRTI. METHODS: retrospective cohort study of data from the Brazilian Influenza Epidemiological Surveillance Information System. Patients under 20 years-old who had severe LRTI with etiological confirmation through RT-PCR between 2020 and 2022 were included. Binary logistic regressions were used to examine associations between pathogens and symptoms. RESULTS: 60,657 cases were assessed. The main viral agents detected were Sars-CoV-2 (COV2) (41.2%), Respiratory Syncytial Virus (29.1%), Human Rhinovirus (HRV) (12.1%), and Influenza (FLU) (5.5%). A general mortality rate of 4.3% was observed. The multivariate analysis evidenced that COV2 less likely presented with cough (OR 0.34; 95%CI 0.32-0.36), respiratory discomfort (Adjusted Odds Ratio (aOR) 0.61; 95%Confidence Interval (CI) 0.59-0.64), and desaturation (aOR 0.71; 95%CI 0.69-0.75). RSV strongly associated with cough (aOR 2.59; 95%CI 2.45-2.75) and respiratory discomfort (aOR 1.54; 95%CI 1.46-1.62), whereas FLU was linked to fever (aOR 2.27; 95%CI 2.06-2.50) and sore throat (aOR 1.48; 95%CI 1.34-1.64). CONCLUSIONS: The viral agents responsible for severe LRTI have distinct associations with clinical features in children.