Central Nervous System Infections in Sudden Unexpected Death in Infancy: A Systematic Review of Autopsy-Based Pediatric Pathology

INTRODUCTION: Sudden unexpected death in infancy (SUDI) remains a major challenge in pediatric and forensic medicine. While infections are recognized contributors, the specific role of central nervous system (CNS) infections identified at autopsy has not been systematically evaluated. MATERIALS AND METHODS: A systematic review was conducted in accordance with PRISMA 2020 guidelines. PubMed/MEDLINE and Scopus were searched without a lower publication-date restriction through 6 April 2026. Studies reporting cases of SUDI associated with CNS infection were included. RESULTS: Sixteen studies met the inclusion criteria. A wide range of pathogens was identified. CNS involvement ranged from severe necrotizing meningoencephalitis to mild leptomeningeal inflammation associated with systemic infection. While some infections were diagnosed only during postmortem investigation, others occurred in infants with preceding clinical manifestations. CONCLUSIONS: CNS infectious pathology represents a heterogeneous autopsy-detected contributor to SUDI, ranging from clearly causal infections to findings whose precise contribution to death remains uncertain.