The PVL threat: A multicenter, single-cohort retrospective study of Panton-Valentine leukocidin staphylococcal infections in critically ill children.

UNLABELLED: Staphylococcus aureus carrying the Panton-Valentine leukocidin (PVL) genes, in both methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains, causes severe infection in previously healthy children. We described critically ill children with PVL-positive infection and explored predictors of prolonged intensive care. In this multicenter, single-cohort retrospective study, we included 44 consecutive children aged 0-16 years with PVL-producing S. aureus infection admitted to a neonatal or pediatric intensive care unit (PICU) at 13 Italian centers between 2022 and 2025. The primary outcome was PICU stay above the cohort median. We used Fisher exact tests and exploratory Firth penalized logistic regression, overall and within age strata, with sensitivity analyses. Median age was 22 months (interquartile range [IQR] 11-123); 5 children (11%) were neonates. MSSA caused 25 cases (57%) and MRSA 19 (43%). Necrotizing pneumonia predominated, with excavation in 34 children (77%). Empyema (52%), acute respiratory distress syndrome (41%), pneumothorax (36%) and septic shock (34%) were the leading complications; 41 children (93%) required respiratory support and 4 (9%) extracorporeal membrane oxygenation. Median PICU stay was 17 days (IQR 10-28); 2 children died (5%). Septic shock was associated with prolonged stay (odds ratio 7.2; 95% CI 1.5-49.3), also after adjustment in children ≥ 1 year (adjusted odds ratio 8.0; 95% CI 1.3-49.8), with consistent but imprecise sensitivity analyses.

CONCLUSION

PVL-producing S. aureus caused life-threatening infection at all pediatric ages. Methicillin resistance was not associated with prolonged stay, supporting PVL testing of S. aureus isolates from critically ill children. Predictors of prolonged stay are exploratory and need prospective confirmation.

WHAT IS KNOWN: • PVL-producing S. aureus causes necrotizing pneumonia and disseminated infection in previously healthy children. • Evidence rests largely on case reports and small series, and infants are underrepresented.

WHAT IS NEW: • In 44 critically ill children, including 5 neonates, MSSA and MRSA produced comparable critical illness. • In exploratory analyses, septic shock was associated with prolonged intensive care; mortality was 5%.