Respiratory viruses and SARS-CoV-2 virus circulation in the provinces of Lucca and Massa Carrara during the 2022/2023 and 2023/2024 flu seasons

Background and Aims: the study aimed to investigate the circulation of influenza viruses and SARS-CoV-2 in the 2022-23 and 2023-24 influenza seasons in the provinces of Lucca and Massa Carrara in the northwest of the Tuscany region. Materials and Methods: a retrospective observational study was conducted on adult and pediatric patients who accessed hospital facilities in the considered area during the influenza periods (from September to April) of 2022-23 and 2023-24. Results: the 2022-23 influenza season was characterized by the circulation of the A/H3N2 influenza virus (84% of the total), with a peak of positive samples from weeks 42 to 52 in 2022. Instead, the influenza A/(H1N1)pdm09 virus was responsible for 94% of influenza infections in the 2023-24 season, with a peak of positive samples between weeks 52 of 2023 and 3 of 2024. Conclusions: effective virological diagnostics and constant monitoring of circulating viruses are mandatory to correctly address therapy and contain the viral circulation in the different influenza seasons.