Severity and complications in infants with respiratory syncytial virus infection after the SARS-CoV-2 pandemic

Background: After the SARS-CoV-2 pandemic, there has been an increase in hospitalization for lower respiratory infection secondary to respiratory syncytial virus (RSV), with greater complications. Associated extrapulmonary alterations, biventricular dysfunction, acute kidney injury, among others, have been found. The objective of this study was to analize the evolution and complications in hospitalized children with lower respiratory infection secondary to RSV after COVID-19 pandemic. Methods: All pediatric patients under 2 years of age admitted to the emergency department with RSV infection were included. Clinical characteristics, need for supplemental oxygen, use of amines, renal angina index, and requirement for renal replacement therapy were analyzed. Lung ultrasound was performed upon admission. Statistical analysis was carried out for the quantitative variables by means of mean and standard deviation, and qualitative variables by frequency and percentage. Differences in the distribution were evaluated with Fisher's exact distribution. Results: 45 patients with RSV infection were identified, 26.7% required invasive mechanical ventilation and 11.1% requiered peritoneal dialysis. Fatality was observed in four cases, three of these younger than 12 months with a LUS score > 7; contrasts with 90.2% of survivors with a score < 7 (p = 0.0004). Conclusions: An increase in the incidence of bronchiolitis after pandemic was observed, with more than half having moderate to severe symptoms and requiring supplemental oxygen support in all patients upon admission. Acute kidney injury is the most common extrapulmonary manifestation.