Human respiratory syncytial virus in children with lower respiratory tract infections or influenza-like illness and its co-infection characteristics with viruses and atypical bacteria in Hangzhou, China

•Co-infections of RSV are common in acute lower respiratory tract infections.•Co-infection of RSV has no significant effect on clinical presentation except fever.•RSV-B shows a more local pattern in Hangzhou.•A new genotype, BA11 was identified.