RSV Bronchiolitis Has Persisting Consequences for Some Children

By Philip R. Fischer, MD, DTM&H

Professor of Pediatrics, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN; Department of Pediatrics, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates

SYNOPSIS: Young children hospitalized with respiratory syncytial virus (RSV) infection are at increased risk of subsequent hospitalization during the following year and of increased need for outpatient healthcare.

SOURCE: Pelletier JH, Au AK, Furman DY, et al. Healthcare use in the year following bronchiolitis hospitalization. Hosp Pediatr 2022;12:937-944.

Bronchiolitis is the leading cause of hospitalization during the first two years of life. Although generally benign and self-limited, the illness can lead to recurrent wheezing (40% of children during the three years following a respiratory syncytial virus [RSV] hospitalization) as well as to treatment with maintenance asthma medication. About 20% of children admitted for bronchiolitis have a subsequent hospitalization for pneumonia or asthma. Approximately 3% to 6% of children admitted with bronchiolitis are re-admitted for inpatient care during the subsequent month. Nonetheless, the actual risk of longer-term hospitalization and the risk of increased healthcare use have been incompletely quantified.

A research team from Pittsburgh used a national database (Pediatric Health Informations Systems, incorporating data from 47 American children’s hospitals) to follow readmissions during the 12 months after an initial bronchiolitis admission as well as, in a smaller dataset, the level of outpatient healthcare use during the year after the initial bronchiolitis admission. Using data from 2010 through 2019, there were 307,306 bronchiolitis admissions involving 271,115 children younger than two years of age. The median age at admission was 5 months, and 19% of hospitalized children had an underlying complex chronic condition (4% prematurity, 3% with a respiratory disorder).

Overall, 18% of children were readmitted during the subsequent 12 months, with the median time of readmission being two months after the initial admission. Ten percent were readmitted for bronchiolitis, and the others were readmitted for different conditions. Of those initially receiving intensive care, 30% were subsequently readmitted (27% of those receiving mechanical ventilation).

For children admitted with bronchiolitis, there was a median of nine outpatient visits during the subsequent 12 months; a small number of patients accounted for a high number of subsequent medical visits. Those receiving the most subsequent outpatient care often had a history of prematurity, a chronic medical condition, or technology dependence. In addition, patients requiring the most subsequent care were largely male, white, from financially affluent areas, and with commercial insurance. Excluding patients with chronic conditions from the analysis, it still seemed as though there was a subset of children hospitalized with bronchiolitis who continued to have increased vulnerability to subsequent respiratory infections.

Of course, post-hospitalization care-seeking does not depend only on disease severity. It also depends on the family’s threshold for seeking care and on their access to (or barriers hindering) care. In fact, it was the wealthier families who were most likely to seek more care following the initial bronchiolitis hospitalization.

COMMENTARY

Essentially every child is infected by RSV during the first two years of life. Some RSV-infected children (and some infected by other viruses) develop bronchiolitis. Some children with bronchiolitis become sick enough to require inpatient care. And, as now shown by Pelletier and colleagues, children sick enough to be hospitalized with RSV infection go home with an increased risk of requiring outpatient care and of needing re-hospitalization during the year after the initial hospitalization. Even though the current winter RSV season will pass, consequences linger.

Several factors prompt some children to become sicker than others with RSV. For instance, breastfeeding is protective against developing bronchiolitis, and environmental exposure to tobacco smoke is a risk for developing bronchiolitis.¹ Obviously, breastfeeding should be encouraged, and passive smoke exposure should be avoided.

Children with family histories positive for asthma are at increased risk of severe RSV illness. It is likely that a familial genetic factor prompts the young child who seems otherwise healthy to fare less well when confronted with RSV infection. Then, having a family history of asthma and/or atopy is predictive of which children then will develop asthma themselves after a hospitalization for bronchiolitis.^1,2 Indeed, in one study, more than half of children hospitalized for bronchiolitis went on to develop asthma.²

Some bronchiolitis-causing viruses yield an even higher risk of subsequent development of asthma than does RSV.³ Beyond family history of asthma, children hospitalized with human bocavirus bronchiolitis have higher risk for subsequently developing asthma than do those hospitalized with RSV bronchiolitis.³ Whatever the viral cause of bronchiolitis, the bacterial microbiome also is relevant to subsequent risks for wheezing.⁴ Children who had relative increases in Moraxella and Streptococcus in nasal secretions three weeks after a bronchiolitis hospitalization were at increased risk of developing recurrent wheezing.⁴

Hospitalization for bronchiolitis also seems to prompt risk of non-respiratory complications. Children receiving intensive care for bronchiolitis have lower neurodevelopmental test scores one to two years after their hospitalization than does a general reference population.⁵

Having “better” insurance and living in more affluent neighborhoods, in Pelletier’s study, were associated with increased medical care after bronchiolitis hospitalizations. While it is conceivable that wealth increases the risk for respiratory complications of bronchiolitis, it is more likely that hospitalization makes children vulnerable to parental concern and care-seeking behaviors and that less affluent families are less able to receive the care they might desire.

REFERENCES

1. Frassanito A, Nenna R, Arima S, et al. Modifiable environmental factors predispose term infants to bronchiolitis but bronchiolitis itself predisposes to respiratory sequelae. Pediatr Pulmonol 2022;57:640-647.
2. Clark AJ, Dong N, Roth T, Douglas LC. Factors associated with asthma diagnosis within five years of a bronchiolitis hospitalization: A retrospective cohort study in a high asthma prevalence population. Hosp Pediatr 2019;9:794-800.
3. Del Rosal T, Garcia-Garcia ML, Calvo C, et al. Recurrent wheezing and asthma after bocavirus bronchiolitis. Allergol Immunopathol (Madr) 2016;44:410-414.
4. Mansbach JM, Luna PN, Shaw CA, et al. Increased Moraxella and Streptococcus species abundance after severe bronchiolitis is associated with recurrent wheezing. J Allergy Clin Immunol 2020;145:518-527.
5. Shein SL, Roth E, Pace E, et al. Long-term neurodevelopmental and functional outcomes of normally developing children requiring PICU care for bronchiolitis. J Pediatr Intensive Care 2020;10:282-288.