Background: – Human noroviruses are a leading cause of acute gastroenteritis worldwide, with GII.4 Sydney 2012 [P16], being the predominant circulating genotype in Italy in recent years. Outbreaks in pediatric hospital wards represent a major public health concern. Methods: – Eight stool samples collected between November 2023 and February 2024 at Brescia Civic Hospital were analyzed by real-time polymerase chain reaction, sequence-independent single-primer amplification and next-generation sequencing. Results: – All isolates belonged to GII.4 Sydney 2012 [P16] genotype. Five isolates from December 2023 clustered tightly together, confirming a nosocomial outbreak with near-complete sequence identity. Isolates from November 2023, January 2024 and February 2024 were phylogenetically distinct, with 1 isolate (January 2024) clustering in a completely separated tree portion, carrying 30 amino acid substitutions and 237 synonymous mutations. Conclusions: – Our analysis confirmed a nosocomial outbreak and underscored the substantial intra-genotypic diversity of GII.4 Sydney 2012 [P16] genotype. These findings highlight the importance of rapid diagnosis, infection control measures and continuous genomic surveillance to track the evolution and global circulation of epidemic noroviruses.
Small Epidemic Outbreak of Norovirus in the Pediatric Department of Brescia Civic Hospital (Northern Italy): Genomic Characterization and Phylogenetic Analysis
Pellegrino, Michele;Marsico, Stefania;
2026-01-01
Abstract
Background: – Human noroviruses are a leading cause of acute gastroenteritis worldwide, with GII.4 Sydney 2012 [P16], being the predominant circulating genotype in Italy in recent years. Outbreaks in pediatric hospital wards represent a major public health concern. Methods: – Eight stool samples collected between November 2023 and February 2024 at Brescia Civic Hospital were analyzed by real-time polymerase chain reaction, sequence-independent single-primer amplification and next-generation sequencing. Results: – All isolates belonged to GII.4 Sydney 2012 [P16] genotype. Five isolates from December 2023 clustered tightly together, confirming a nosocomial outbreak with near-complete sequence identity. Isolates from November 2023, January 2024 and February 2024 were phylogenetically distinct, with 1 isolate (January 2024) clustering in a completely separated tree portion, carrying 30 amino acid substitutions and 237 synonymous mutations. Conclusions: – Our analysis confirmed a nosocomial outbreak and underscored the substantial intra-genotypic diversity of GII.4 Sydney 2012 [P16] genotype. These findings highlight the importance of rapid diagnosis, infection control measures and continuous genomic surveillance to track the evolution and global circulation of epidemic noroviruses.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
