O2112: Comparing the Clinical Outcomes of Human Rhinovirus/enterovirus to Influenza and Respiratory Syncytial Virus Among Children in an Outpatient Setting

Background: Human rhinovirus/enterovirus (HRV/ENT) infections are exceedingly common among children and cause significant morbidity. Data regarding their clinical impact are limited, inconsistent, and focus largely on an inpatient population. We aimed to compare the clinical outcomes of children with HRV/ENT infection to Influenza A/B (FLU) and Respiratory Syncytial Virus (RSV) in the outpatient setting.

Methods: We conducted a retrospective analysis of respiratory samples positive for HRV/ENT, FLU, or RSV from patients ≤ 17 years of age submitted to Tripler Army Medical Center’s diagnostic laboratory between 2016 and 2019. Samples positive for more than one virus or arising from the same patient within 3 months were excluded. Specimens were tested using BioFire® FilmArray® Respiratory Panel. Chart reviews were conducted by trained medical staff to assess outcome measures and comorbid conditions including prematurity, immune metabolic conditions, or cardiopulmonary disease. Outcome measures included: days of respiratory symptoms before viral testing; number of outpatient visits for respiratory symptoms in the seven days before and 14 days after positive test; and bacterial diagnosis or hospital admission in the 14 days after positive test. Multivariable linear regression and the Kruskal-Wallis Test was used to compare the number of days of respiratory symptoms and number of outpatient visits between viruses, respectively. Multivariable logistic regression with 95% confidence intervals (CI) was used to compare clinical outcomes between viruses for categorical outcomes.

Results: There were 1357 positive results included in our analysis; 746 HRV/ENT, 304 FLU, and 309 RSV. After controlling for comorbid conditions, children with FLU infection had 29% fewer days of respiratory symptoms prior to testing when compared to HRV/ENT (Figure 1A). Children with FLU (median = 1 visit) infection had fewer outpatient visits for respiratory symptoms surrounding testing when compared to HRV/ENT (median = 2 visits) or RSV (median = 2 visits), p= < 0.001 (Figure 1B). After adjusting for age and comorbid conditions, children with RSV infection had three times the odds of bacterial infection (OR 3.57; 95% CI: 1.83, 6.96; p < 0.001) than children with HRV/ENT and children with FLU had nearly 80% decreased odds of hospitalization (OR 0.19; 95% CI: .08, .48, p < 0.001) compared to children with HRV/ENT (Figure 2).

Conclusion: In our analysis, children with HRV/ENT had more days of symptoms, more outpatient visits, and higher odds of hospitalization as compared to those with FLU, which underscores the clinical significance of the pathogen. In contrast, children with RSV had similar number of outpatient visits, but were found to have increased odds of bacterial infection as compared to those with HRV/ENT. Previous studies demonstrate that ~40% of children hospitalized with RSV bronchiolitis had bacterial co-infections. This is consistent with our findings and supports a low threshold for further infectious workup in known RSV positive children.