Respiratory syncytial virus in influenza-like illness cases: Epidemiology and molecular analyses of four consecutive winter seasons (2014-2015/2017-2018) in Lombardy (Northern Italy).

In this study, RSV significantly contributed to ILI cases, especially among pediatric population (<15 years), although it was detected in all age groups. RSV-B predominated on RSV-A, and the most recent evolved genotypes (BA and ON1, respectively) circulated. Investigating the epidemiological and molecular characteristics of RSV in ILI cases can increase baseline epidemiological information before the introduction of RSV vaccination.