Clinical Burden of Respiratory Syncytial Virus in Hospitalized Children Aged ≤5 Years (INSPIRE Study)

Abstract

Background: Respiratory syncytial virus (RSV) is a leading cause of hospitalizations in children (≤5 years of age); limited data compare burden by age.

Methods: This single-center retrospective study included children (≤5 years of age) hospitalized for >24 hours with reverse-transcription polymerase chain reaction (RT-PCR)-confirmed RSV infection (2015-2018). Hospital length of stay (LOS), intensive care unit (ICU) admissions, ICU LOS, supplemental oxygen, and medication use were assessed. Multivariate logistic regression analyses identified predictors of hospital LOS >5 days.

Results: Three hundred twelve patients had RSV infection (ages 0 to <6 months [35%], 6 to <12 months [15%], 1 to <2 years [25%], and 2-5 years [25%]); 16.3% had predefined comorbidities (excludes preterm infants). Median hospital LOS was 5.0 days and similar across age; 5.1% (16/312) were admitted to ICU (ICU LOS, 5.0 days), with those aged 0 to <6 months admitted most frequently (10/108 [9.3%]). Supplemental oxygen was administered in 57.7% of patients, with similar need across ages. Antibiotics were administered frequently during hospitalization (43.6%). Predictors of prolonged LOS included pneumonia (odds ratio [OR], 2.33), supplemental oxygen need (OR, 5.09), and preterm births (OR, 3.37). High viral load (RT-PCR RSV cycle threshold value <25) was associated with greater need for supplemental oxygen.

Conclusions: RSV causes substantial burden in hospitalized children (≤5 years), particularly preterm infants and those aged <6 months.

Keywords: burden of disease; children; hospitalization; infant; predictors.

Figure 1.

Overall median hospital length of stay (LOS) in hospitalized pediatric patients with respiratory syncytial virus infection (N = 312), stratified by age. The length of the box represents the interquartile range (IQR), the horizontal line within the box represents the median value, the whiskers represent the 1.5 IQR of the 25th quartile or 1.5 IQR of the 75th quartile, and the stars represent outliers.

Figure 2.

Predictors for prolonged hospital length of stay (LOS) (>5 days) (A) and intensive care unit (ICU) admission (B) in hospitalized pediatric patients with respiratory syncytial virus infection (N = 312). Estimated odds ratios (ORs) and 95% confidence intervals (CIs) for selected covariates based on multivariate logistic regression with stepwise selection. A threshold of 15% for selecting criteria for stepwise approach in multivariate logistic regression modeling was applied to identify the most impactful predictors on the outcome of interest. The cycle threshold (Ct) value, defined as the number of cycles required for the fluorescent signal to cross the threshold of detection, is inversely proportional to the viral load; values of <25 are indicative of a high viral load, whereas values of ≥25 indicate a moderate or low viral load. The denominator used to calculate proportions shown in the Overall column is the overall population number (N = 312). To calculate each proportion shown in the hospital LOS >5 days and admitted to ICU columns, the total number of patients within each subgroup was used as the denominator. *Patient pathway was classed as general practitioner (GP) if patients were seen by the GP before being admitted, emergency department (ED) if patients presented directly to the ED without any prior GP or outpatient ward visit, and outpatient ward if patients were seen in an outpatient ward before being admitted.