This population-based prospective study set out to establish the rates of respiratory syncytial virus (RSV)-associated paediatric respiratory tract infections in both inpatient and outpatient settings. Cases were identified through the New Vaccine Surveillance Network, a Centre for Disease Control initiative to survey acute respiratory infections in children aged <5 years in three geographically diverse US counties. The study was conducted during November to April between 2000 and 2004.

Nasal and throat swabs were analysed by RT-PCR and culture for RSV and other viruses including influenza, parainfluenza, rhinovirus and metapneumovirus. Of 6225 children with acute respiratory infections identified during the surveillance period, 5067 (81%) were enrolled of which 919 (18%) were RSV-positive; 6% of those were co-infected, most commonly with influenza virus. Three hundred and fifty-five RSV-infected children (39%) were treated in the community or emergency department. Those hospitalised (61%) were more likely to be under 6 months of age (58% vs 25% of outpatients) and to have been born prematurely (16% vs 8% of outpatients). The only socioeconomic factors found to be significantly associated with the risk of hospitalisation were breast feeding of less than 1 month duration and the presence of preschool children within the household.

This study attempts to identify the burden of RSV-associated acute respiratory infections in the community and hospital settings. While infection trends may be similar in the UK paediatric population, rates of hospitalisation are likely to vary.

▸ Hall CB, Weinberg GA, Iwane MK, et al. The burden of respiratory syncytial virus infection in young children. N Engl J Med 2009;360:588–98.