Risk factors associated with severe RSV disease among hospitalized children in the second year of life: a multicenter study

Abstract

Purpose: The second year of life is gaining increased attention in the era of long-acting RSV immunoprophylaxis. This multicenter study, across pre- and post-COVID seasons, aimed to assess the association between specific key risk-factors and severe RSV-related disease among hospitalized children aged 12-23 months.

Methods: This retrospective study included children aged 12-23 months hospitalized with RSV across 11 medical-centers (2017-2021). We compared outcomes of prolonged hospitalization (> 3 days) and PICU (Pediatric Intensive Care Unit) admission for children with risk factors (prematurity < 37 weeks, major congenital heart disease (CHD), chronic lung disease of prematurity (CLD) or Down syndrome (DS)) and those without the respective risk factor, adjusting for demographic variables and COVID-19 pandemic admission. Clinical outcomes were also compared between children with ≥ 1 risk factors and those with none.

Results: Among 1023 children, 228 (22%) had ≥ 1 risk factor: prematurity (n = 183), CLD (n = 28), CHD (n = 45) or DS (n = 20). In multivariable analysis, prematurity with CLD (aOR 4.7,95%CI:1.97-11.22) or without CLD (aOR 2.26, 95%CI:1.54-3.3), CHD (aOR-3.29, 95%CI:1.6-6.77), DS (aOR-4.14, 95%CI:1.26-13.6) and having ≥ 1 risk (aOR-3.55, 95%CI:2.55-4.96) were independently associated with prolonged hospitalization. DS (aOR 6.7, 95%CI:2.1-22.4), CHD (aOR 3.0,95%CI:1.04-8.66) and having ≥ 1 risk factor (aOR-3.58, 95%CI:1.89-6.80) were also associated with PICU admission.

Conclusion: Children aged 12-23 months with prematurity, CLD, major CHD or DS had significantly higher rates of prolonged RSV hospitalization. Those with ≥ 1 risk factor, and presumably patients with DS and CHD are at highest risk for severe complications. Preventive strategies for these high-risk populations should be considered in their second-year of life.

What is known: • Children with prematurity, congenital heart disease (CHD), chronic lung disease of prematurity (CLD) or Down syndrome (DS) are at increased risk for severe RSV-related illness in the first year of life. • The second year of life is now relevant for long-acting RSV prevention strategies.

What is new: • This multicenter study shows that prematurity, CLD, CHD, and DS remain strong predictors of prolonged RSV hospitalization in children aged 12-23 months. • Those with ≥ 1 risk factor, and presumably those with DS and major CHD, faced the highest risk, with increased likelihood of PICU admission.

Keywords: Bronchiolitis; Chronic lung disease; Congenital heart disease; Down syndrome; Prematurity; Respiratory Syncitial Virus (RSV).

Fig. 1

Forest plot of multivariate analysis of the relationship between individual risk factors (CHD, DS, preterm with CLD vs term and preterm without CLD vs term), relevant covariates and each primary outcome including LOS > 3day—yes/no and PICU admission

Fig. 2

Forest plot of the multivariable analysis of the relationship between having > 1 risk factor, relevant covariates and each primary outcome including LOS > 3day—yes/no and PICU admission