BackgroundRespiratory syncytial virus (RSV) is the predominant viral pathogen associated with acute lower respiratory infection (ALRI) in children under five years of age (<5y). Little is reported on the national estimates of RSV-ALRI hospitalisations in <5y based on robust RSV epidemiology data.MethodsWe included data on RSV and ALRI hospitalisation in <5y from systematic literature reviews (including unpublished data) and from inpatient databases, representing 58 countries. We used two different methods, namely the rate-based method and the proportion-based method, to estimate national RSV-ALRI hospitalisations in <5y in the year of 2019. The rate-based method synthesized data on laboratory-confirmed RSV-ALRI hospitalisation rates using a spatiotemporal Gaussian process meta-regression (ST-GPR). The proportion-based method applied data on RSV positive proportions among ALRI to all-cause ALRI hospitalisation envelopes using a Bayesian regularized trimmed meta-regression (MR-BRT). Where applicable, we reported estimates by both methods in order to provide a plausible range for each included country.FindingsA total of 334 studies and 1985 data points were included in the analysis, accounting for 59% (398 million/677 million) of the <5y population worldwide. We reported the number of the annual national RSV-ALRI hospitalisations for 29 countries using the rate-based method and 42 countries using the proportion-based method. Despite great variation among countries, a high proportion of the RSV-ALRI hospitalisations were in infants <1y in all countries (median proportion: 45%, interquartile range: 32–56). In most (76%, 272/358) of the study years, RSV-ALRI hospitalisation rate fluctuated between 0·8 and 1·2 fold of country’s median yearly rate. General agreement was observed between estimates by the rate-based method and proportion-based method, with a few exceptions in India, Kenya, Norway and Philippines.
InterpretationBy incorporating data from various sources, our study provides robust estimates on the national burden of RSV-ALRI hospitalisation in <5y. These estimates are important for informing policy for introduction of RSV immunisations and also serve as baseline data for RSV disease burden in young children.