Invited Commentary 

Pediatrics

March 6, 2025

Changes in Respiratory Viral Testing Before and After the COVID-19 Pandemic

Todd W. Lyons, Caroline G. Kahane

JAMA Netw Open. 2025;8(3):e250168. doi:10.1001/jamanetworkopen.2025.0168

As an intern during the winter of 2008, I presented a full service of children admitted overnight with bronchiolitis. It had been 2 years since the initial publication of the American Academy of Pediatrics’ “Diagnosis and Management of Bronchiolitis” guideline, which recommended against routine viral pathogen testing.¹ As I reported that the final child on the service had a positive respiratory syncytial virus test, my bewildered attending asked, “Why do they continue to send these tests on children when they don’t change management?” At the time, we were amid a massive deimplementation effort to reduce respiratory pathogen testing.

Now, 17 years later, I am the attending in the emergency department working with a family who is demanding to know exactly which virus is causing their otherwise healthy child’s fever of 4 hours’ duration after their rapid COVID-19 test returned negative. Like many clinicians, I am left wondering how we moved from telling most families that their child had a virus in need of only good supportive care to needing to know exactly which virus is responsible for their symptoms? And importantly, can and should we ever go back?

This change in approach to respiratory pathogen testing, as experienced by author T.W.L., is likely familiar to many frontline clinicians and is described in the article by Molloy et al.² In this study, the authors leveraged data from the Pediatric Health Information System database and examined trends in respiratory pathogen testing for over 5 million encounters for respiratory illnesses at 39 children’s hospitals before and after the COVID-19 pandemic. They found that between 2016 and 2023, children and adolescents presenting to the emergency department or hospitalized with a respiratory illness had a 4.6-fold increase (from 13.6% in 2016 to a peak of 62.2% in 2022) in respiratory pathogen testing, with the largest increase observed in patients seen and discharged from the emergency department (a 6.7-fold increase [from 8.8% in 2016 to a peak of 59.3% in 2022]). While this rise in testing was driven initially by COVID-19–only testing, multitarget viral panels currently comprise the majority of viral testing performed. As expected with any rise in utilization, the authors found a corresponding 3.7-fold increase (from a low of $20.6 million in 2016 to a high of $111.0 million in 2022) in inflation-adjusted costs for viral pathogen testing at these visits, including a significant 8.6-fold increase (from a low of $34.2 in 2017 to a high of $128.2 in 2022) in per-encounter costs for viral pathogen testing for patients discharged from the emergency department. In total, over $83 million was spent on respiratory pathogen testing for patients with respiratory illnesses in 2023 alone.

The study by Molloy et al² raises important questions about how we got to this point with viral pathogen testing and how—or if—we should return to prepandemic practice patterns. The initial rise in respiratory pathogen testing may have been driven by the need to appropriately identify patients with COVID-19 for both epidemiologic and isolation precaution reasons. However, as rapid platforms for COVID-19 identification were rolled out, the decision was made to frequently include influenza and respiratory syncytial virus testing within the same panel. Other multiplex platforms now exist facilitating the identification of over 20 viral pathogens with rapid turnaround times.³ However, the question remains: How do these tests impact patient management? Identification of viral pathogens has a role in generating patient cohorts, instituting public health initiatives (ie, epidemiologic tracking), identifying certain patients for whom viral therapies exist (eg, oseltamivir for influenza), and at times, preventing additional expensive or invasive testing and treatment (eg, a patient with a fever of 5 days who may be able to forego a more extensive workup if known to have adenovirus). Furthermore, limited data suggest that children with bronchiolitis with specific viral etiologies such as rhinovirus may be more responsive to certain therapies such as beta-agonist treatment or steroids.⁴ However, these data are limited, and additional trials are needed prior to making broad recommendations for changes in the management of bronchiolitis by viral pathogen. Therefore, for many children with respiratory illnesses, respiratory pathogen testing does not change clinical management.⁵ This is especially true for children and adolescents well enough to be discharged from the emergency department, which is the exact population for whom the authors observed the largest increase in testing. Clinicians should therefore consider for which patients viral pathogen testing would change management and add value and should avoid testing those for whom it will add cost without changing management or outcomes.

Troublingly, Molloy and colleagues² found a modestly higher rate (difference, 6.0%) of respiratory pathogen testing for patients from the highest Child Opportunity Index neighborhoods (40.4%) compared with those from the lowest (34.4%). This finding mirrors other recent studies that show low-value care, defined as the delivery of health care services for which the potential benefits do not outweigh the harms and costs,⁶ to be more common among children living in higher opportunity neighborhoods.⁷ Further work is needed to understand factors driving this disparity and to take steps to ensure that viral testing is performed when it will impact the care of a child, regardless of the zip code in which the child lives.

The study by Molloy and colleagues² underscores the need for consensus surrounding situations in which respiratory viral pathogen testing is necessary and cost-effective. Once defined, we should strive to reduce testing for children and adolescents in situations in which respiratory pathogen testing will not change management. To accomplish this and to reduce the important disparities identified by study, we should consider the role of clinical pathways and quality-improvement initiatives in the creation of more standardized approaches to viral pathogen testing. For these efforts to be successful, we will also need buy-in from parents, schools, and public health officials. This may be a challenge, as a new generation of parents, teachers, and clinicians has grown accustomed to routine viral testing. Therefore, it may likely take years to return to a time when families are comfortable being told their child has just a virus without the need to know which.