Respiratory syncytial virus positivity among hospital admissions for acute respiratory illness in children younger than 5 years of age in low- and middle-income countries: a systematic review and meta-analysis

TL;DR

This study estimates that respiratory syncytial virus (RSV) is responsible for about a quarter of hospital admissions for respiratory illness in children under five in low- and middle-income countries.

Contribution

The study provides a comprehensive global estimate of RSV positivity in young children hospitalized with acute respiratory illness in low- and middle-income countries.

Findings

RSV positivity was highest among infants under six months, with nearly half of hospital admissions possibly due to RSV.

RSV positivity varied by region, with the highest rates in the European region.

The study found significant heterogeneity in RSV positivity based on factors like region and specimen type.

Abstract

To estimate the proportion RSV-positive among children aged < 5 years hospitalized with ARI in low- and middle-income countries (LMIC), where 97% of RSV mortality occurs.

We conducted a systematic literature search for studies conducted pre-COVID-19 and published 2010—2022 (PROSPERO registration CRD42022361351). We estimated the RSV percent positivity and 95% confidence interval (CI) using random-effects meta-analyses. We assessed heterogeneity in RSV percent positivity using subgroup analyses and univariable meta-regression models. We assessed the influence of study sample size in sensitivity analyses.

Seventy-three studies conducted in 37 LMICs were included. The summary estimate of percent RSV-positive from the meta-analysis of children < 5 years hospitalized with ARI was 26.2% (95% CI: 24.3–28.3%), ranging from 18.9% (16.4–21.6%) among children 6– < 60 months to 41.3% (36.4–46.4%) among children 0– < 6 months. Only five studies included children aged < 2 months, but RSV positivity was high among this group (40.2% [35.8–44.7%]). Percent positivity stratified by WHO region ranged from 23.6% in the Africa and Southeast Asian regions to 37.5% in the European region. RSV positivity was similar across country income groups. Univariable meta-regression models indicated that there was significant heterogeneity in RSV percent positivity across subgroups defined by mid-year of the study period, WHO region, number of study sites, recruitment method, hospital type, and specimen type (p < 0.05).

RSV detection was high among children aged < 5 years hospitalized with ARI in LMICs across all WHO regions, especially among infants aged < 6 months, among whom RSV may account for almost up to one-half of all ARI hospital admissions. Recent WHO-recommended RSV immunization for all countries may protect young infants aged < 6 months against severe RSV disease.

The online version contains supplementary material available at 10.1186/s12889-026-26743-4.

Figures