Severe pneumonia in children with influenza A-Staphylococcus aureus coinfection: case report

Severe community-acquired pneumonia caused by coinfection with influenza A virus and Staphylococcus aureus (S. aureus) is rare but may lead to rapid clinical deterioration and high mortality. We report two pediatric cases of severe pneumonia associated with influenza A virus-S. aureus coinfection. Both patients initially presented with nonspecific influenza-like symptoms, followed by rapid progression to acute respiratory failure. One case was characterized by necrotizing pneumonia complicated by pneumothorax and empyema, with S. aureus isolated from respiratory specimens and pleural fluid. The other case developed S. aureus bloodstream infection, progressing to septic shock and multiple organ dysfunction syndrome. Both children required prolonged invasive mechanical ventilation and multidisciplinary intensive care, including targeted antimicrobial therapy, organ support, and surgical intervention. Antimicrobial treatment consisted of vancomycin with adjunctive linezolid for 4-6 weeks. Despite severe disease, both patients achieved clinical recovery and were discharged, although residual pulmonary abnormalities were observed on follow-up. These cases highlight the heterogeneous clinical presentations of influenza-associated S. aureus coinfection in children. Early recognition, timely optimization of antimicrobial therapy, and comprehensive supportive management are essential to improve outcomes in this potentially life-threatening condition.