P4.055: Impact of the COVID-19 Pandemic on Pediatric Respiratory Virus Patterns: A 7-Year (2018-2024) Incidence Rate Study of 13 Viral Pathogens in the United States

Background: Pediatric respiratory viral infections exhibit seasonal patterns, but the CoVID-19 pandemic significantly disrupted their circulation and timing. Understanding how various respiratory viruses behaved before, during, and after the pandemic is critical for public health preparedness. This study analyzes incidence rate trends of 13 respiratory viruses in the U.S. pediatric population over a seven-year period.

Methods: We performed a retrospective analysis using the TriNetX database. Pediatric patients (≤18 years) across the U.S. with at least one positive test for any of 13 respiratory viruses (identified via LOINC codes) from Jan 1, 2018 to Dec 31, 2024 were included. Children who were immunocompromised or had chronic respiratory or gastrointestinal diseases were excluded. Incidence rates were calculated as new cases per total population per bimonthly interval (Jan–Feb, Mar–Apr, etc.). Incidence trends were compared across three time periods: pre-CoVID-19 (2018–Feb 2020), CoVID-19 (Mar 2020–Dec 2021), and post-CoVID-19 (Jan 2022–Dec 2024). Thirteen viruses were categorized into four groups: RSV, COVID-19, Influenza A/B, and “Other Viruses” (including rhinovirus, adenovirus, metapneumovirus, parainfluenza, enterovirus, and bocavirus).

Results: In a pediatric population of 17,534,753, total respiratory virus incidence rates [Figure 1] were lowest in the pre-CoVID era (mean 0.000061) but surged during the CoVID era (0.000380) and remained elevated post-COVID (0.000346). Pre-pandemic years (2018–2019) exhibited typical seasonality with winter peaks, primarily driven by RSV and influenza A [Figure 2]. During the pre-CoVID period, the highest incidence was noted for Influenza A/B (0.000091), followed by Other Viruses (0.000069), RSV (0.000008). and negligible rates of CoVID-19 (pre-pandemic baseline)[Figure 2]. The CoVID era saw a stark rise in CoVID-19 incidence (0.000360), while Influenza A/B (0.000080) and Other Viruses (0.000119) decreased compared to pre-CoVID levels, likely due to widespread public health restrictions. RSV remained suppressed (0.000005). SARS-CoV-2 emerged with distinct pediatric waves, peaking in 2021 (0.000700) [Figure 2]. Post-CoVID, incidence rates increased across all virus groups. Other Viruses became the most prominent group (0.000336), followed by Influenza A/B (0.000273), CoVID-19 (0.000297), and RSV (0.000010)[Figure 2]. Notably, Other Viruses consistently demonstrated higher incidence than RSV throughout the study period.

Conclusion: Respiratory virus circulation patterns among U.S. children shifted significantly during and after the CoVID-19 pandemic. While CoVID-19 introduced a novel burden, the resurgence of multiple respiratory viruses, especially those grouped under “Other Viruses” have contributed more substantially to the overall incidence than RSV. Additionally, influenza virus incidence rates more than doubled post-CoVID, further adding to the total respiratory virus burden. These trends emphasize the importance of continued surveillance and adaptive clinical planning, especially as post-pandemic viral dynamics no longer follow traditional seasonal expectations.