Global, Regional, and National Disease Burden Estimates of Acute Lower Respiratory Infections Due to Respiratory Syncytial Virus in Young Children in 2019: A Systematic Analysis

Abstract

Background: Respiratory syncytial virus (RSV) is the predominant cause of acute lower respiratory infection (ALRI) in young children. We previously estimated that globally in 2015, 33·1 million episodes of RSV-associated ALRI occurred in children aged 0?<60 months, resulting in a total of 118,200 community and in-hospital deaths. Since then, several community surveillance studies have been conducted to obtain a more precise estimation of RSV associated community deaths. We aimed to update RSV-associated ALRI morbidity and mortality at global, regional and national levels in children aged 0?<60 months for 2019.Methods: We expanded our global RSV disease burden dataset by obtaining new data from an updated systematic literature review (including papers published between 1st January 2017 and 31st December 2020) as well as unpublished data from 51 high-quality studies. Generalised linear mixed-effects model (GLMM) was applied to estimate RSV-associated ALRI incidence, hospital admission and in-hospital mortality both globally and regionally (by country development status and by World Bank Income Classification) in 2019. Country-level RSV-associated ALRI incidence was estimated through a risk-factor based model. We developed new models (through GLMM) that incorporated the latest RSV community mortality data for estimating overall RSV mortality (i.e., in-hospital and out-of-hospital / community).Findings: We estimated that globally in 2019, there were 33·0 million (uncertainty range, UR: 25·4?44·6) RSV-associated ALRI episodes, 3·6 million (2·9?4·6) RSV-associated ALRI hospital admissions, 26300 (15100?49100) RSV-associated ALRI in-hospital deaths, and 101400 (84500?125200) RSV-attributable overall deaths in 0?<60 months. In infants aged 0?<6 months, there were 6·6 million (4·6?9·7) RSV-associated ALRI episodes, 1·4 million (1·0?2·0) RSV-associated ALRI hospital admissions, 13300 (6800?28100) RSV-associated ALRI in-hospital deaths, and 45700 (38400?55900) RSV-attributable overall deaths. 2·0% (1·6?2·4) of overall deaths in 0?<60 months and 3·6% (3·0?4·4) of overall deaths in 28 days?<6 months were attributable to RSV. Low- and middle-income countries (LMICs) accounted for more than 95% of RSV-associated ALRI episodes and more than 97% of RSV-attributable deaths across all age bands.Interpretation: RSV represents substantial morbidity and mortality burden globally in 0?<60 months, especially during the first six months of life and in LMICs. We highlight the striking overall mortality burden of RSV disease, with one in every 50 deaths in 0?<60 months and one in every 28 deaths in 28 days?<6 months being attributable to RSV globally. RSV passive immunisation programmes targeting protection during the first six months of life could have a substantial effect on reducing RSV disease burden.