Case Report: Multiple organ dysfunction syndrome in a preterm infant secondary to respiratory syncytial virus and bacterial co-infection.

This article reports a case of a 1-month 11-day-old preterm infant, born at 36 + 6 weeks gestation, who presented to an outside hospital emergency department with a persistent cough that had not improved over four days. During this period, the infant progressively developed respiratory distress and lethargy. The infant subsequently developed cardiopulmonary arrest, underwent cardiopulmonary resuscitation, and was transferred to our hospital under endotracheal intubation with positive pressure ventilation. Respiratory pathogen polymerase chain reaction testing of a throat swab was positive for respiratory syncytial virus (RSV), while sputum and bronchoalveolar lavage fluid culture and blood metagenomic next-generation sequencing (mNGS) detected Haemophilus influenzae and S. pneumoniae. After 22 days of hospitalization and treatment including invasive mechanical ventilation, antibiotic adjustment, intravenous immunoglobulin (IVIG), and dexamethasone, the infant was discharged without further complications. Metagenomic next-generation sequencing provides rapid diagnostic evidence for mixed infections, while integrated interventions, including IVIG, short-course corticosteroids, and nutritional support, effectively modulate immune responses.