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Published on: December 10, 2013
Clinical Testing for COVID-19, Influenza, and RSV in Hospitalized Youths, 2016-2024
Ariana P Toepfer1, Rachel E Rutkowski1, Leila C Sahni2,3
1National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia.
Insights
Clinical testing for SARS-CoV-2 decreased in hospitalized children and adolescents, while testing for influenza and RSV increased. By 2023-2024, about three-quarters of these young patients were tested for all three viruses.
Area of Science:
- Pediatric Infectious Diseases
- Respiratory Virus Epidemiology
- Clinical Diagnostics
Background:
- Clinical testing is crucial for studying respiratory viruses like COVID-19, influenza, and RSV, especially with electronic health record data.
- Limited data exist on clinical testing practices for these viruses in pediatric populations, hindering accurate study interpretation.
Purpose of the Study:
- To analyze trends in clinical testing frequency for SARS-CoV-2, influenza, and RSV in hospitalized children and adolescents from 2016-2024.
- To estimate the proportion of cases missed by relying solely on clinical testing.
- To identify patient factors associated with receiving clinical testing.
Main Methods:
- A cross-sectional study analyzed data from 26,073 hospitalized children and adolescents across 6 US medical centers (2016-2024).
- Data included prospective surveillance and in-hospital clinical molecular testing for SARS-CoV-2, influenza, and RSV.
- Patient characteristics such as age, intensive care unit (ICU) admission, and underlying medical conditions were recorded.
Main Results:
- SARS-CoV-2 testing decreased from 90.4% (2020-2021) to 76.0% (2023-2024).
- Influenza and RSV testing increased significantly: influenza from 44.5% (2016-2020) to 74.4% (2023-2024); RSV from 42.0% (2016-2020) to 71.6% (2023-2024).
- ICU admission and underlying conditions were associated with higher likelihood of clinical testing.
Conclusions:
- Clinical testing patterns for pediatric respiratory viruses have shifted, with decreased SARS-CoV-2 testing and increased influenza and RSV testing.
- By the 2023-2024 season, approximately 75% of hospitalized children and adolescents were tested for these three key viruses.
- Understanding these testing trends is vital for interpreting epidemiological studies and disease burden assessments.
Importance:
Studies of COVID-19, influenza, and respiratory syncytial virus (RSV) disease clinical epidemiology, disease burden, and vaccine effectiveness often rely on clinical testing to identify cases, particularly with increasing use of electronic health record data. However, few data are available describing clinical testing practices to inform interpretation of these studies.
Objective:
To characterize clinical testing frequency for SARS-CoV-2, influenza, and RSV among children and adolescents hospitalized with acute respiratory illness during the 2016 to 2024 respiratory illness seasons by age, intensive care unit admission, and time period (2016-2020 and each season in 2020-2024); estimate the case fraction missed by clinical testing alone; and identify patient characteristics associated with clinical testing.
Design, Setting, And Participants:
This cross-sectional study analyzed data collected through prospective surveillance with systematic molecular testing (surveillance testing) for SARS-CoV-2, influenza viruses, and RSV among children and adolescents younger than 18 years hospitalized with acute respiratory illness at 6 US medical centers during the winter respiratory illness seasons of 2016 to 2024. In-hospital clinical molecular testing data were abstracted from the medical record.
Main Outcomes And Measures:
The proportion of children and adolescents with clinical molecular testing for SARS-CoV-2, influenza viruses, and RSV.
Results:
During 2016 to 2024, a total of 26 073 hospitalized youths were enrolled (14 459 aged <2 years [55.5%]; 14 833 male [56.9%]), including 12 090 youths during 2016 to 2020 combined. Overall, 10 450 youths (40.1%) had an underlying medical condition. The proportion of youths with clinical testing decreased for SARS-CoV-2 from 3965 of 4388 youths (90.4%) during 2020 to 2021 to 2802 of 3685 youths (76.0%) during 2023 to 2024 (P < .001). In contrast, clinical testing increased from the 2016 to 2020 seasons to the 2023 to 2024 season for influenza viruses (5384 of 12 090 youths [44.5%] to 2740 of 3685 youths [74.4%]; P < .001) and RSV (5072 youths [42.0%] to 2638 youths [71.6%]; P < .001). During the 2023 to 2024 season, the proportion of youths identified as positive for each virus by surveillance testing alone (ie, without clinical testing) was 23 of 112 youths (20.5%) for SARS-CoV-2, 78 of 286 youths (27.3%) for influenza, and 290 of 979 youths (29.6%) for RSV; youths were more likely to receive clinical testing if they were admitted to the intensive care unit (eg, SARS-CoV-2: adjusted odds ratio [aOR], 2.62; 95% CI, 2.06-3.33) or had underlying conditions (eg, any vs no underlying condition for SARS-CoV-2: aOR, 1.56; 95% CI, 1.33-1.84).
Conclusions And Relevance:
In this study, SARS-CoV-2 clinical testing decreased between 2020 to 2021 and 2023 to 2024 seasons, whereas influenza and RSV testing increased significantly between 2016 to 2020 and 2023 to 2024 seasons; approximately three-quarters of children and adolescents were tested for the 3 viruses in 2023 to 2024.
