Trends in Pediatric Viral Symptoms, Influenza Testing, and SARS-CoV-2 Testing From a Statewide Electronic Health Record Consortium, January 2017 to July 2021.

OBJECTIVE

The heterogeneous implementation and uptake of nonpharmaceutical interventions (NPIs) during the coronavirus disease 2019 (COVID-19) pandemic amplified the need for locally responsive disease surveillance mechanisms. Using data from a newly developed statewide electronic health record (EHR) consortium in Minnesota, we sought to characterize trends in pediatric viral symptoms, influenza testing, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing.

METHODS

We conducted a serial cross-sectional analysis of EHR data from 1/1/2017 to 7/30/2021 across 8 large health systems in Minnesota. We included patients ≤18 years of age with any SARS-CoV-2 test, influenza test, or documented diagnostic code which met our viral symptom definition. We plotted week-by-week trends in viral symptoms, SARS-CoV-2 and influenza testing, and test positivity, stratified between children (0-11 years) and adolescents (12-18 years).

RESULTS

We identified 1,079,924 patients ≤18 years of age with viral symptoms or testing; 880,669 (81.5%) were children ≤11 years. Influenza testing and influenza test positivity remained well below historical averages from March 2020 through mid-May 2021. Peaks in viral symptoms during this time were concomitant with peaks in SARS-CoV-2 testing and test positivity, whereas influenza testing and test positivity remained stagnant. Influenza test positivity rates increased substantively among children from May through July 2021.

CONCLUSIONS

Viral illness and influenza testing among pediatric patients were below historical averages throughout the COVID-19 pandemic. Ongoing increases in influenza test positivity may merit clinical and public health awareness and intervention. Future NPI policies can be better targeted with insights from collaborative EHR-based surveillance, which enhances real-time, locally sensitive measurement of disease outbreaks.