584 - Respiratory virus testing practices during the COVID-19 pandemic at pediatric hospitals: a Canadian immunization monitoring program, ACTive, study

Poster Number: 584
Publication Number: 584.176

Background: Understanding the epidemiology and disease severity of SARS-CoV-2 and other respiratory virus co-infections requires accounting for changes in respiratory virus testing practices during the COVID-19 pandemic.

Objective: To evaluate shifts in respiratory virus testing practices at 13 tertiary-care pediatric hospitals affiliated with the Canadian Immunization Monitoring Program, ACTive (IMPACT), which covers ~90% of all Canadian tertiary-care pediatric beds.

Design/Methods: A survey was conducted among IMPACT centers from March-September 2023, gathering data on respiratory virus testing practices and the number of non-COVID-19 multiplex-PCR tests conducted during the immediate pre-pandemic (January-December, 2019), early pandemic (January-August, 2020), and late pandemic (September, 2020-December, 2022) eras.

Results: Testing practices varied across hospitals and eras (Figure A). The use of multiplex-PCR testing for all children with acute respiratory infections (ARIs) decreased from 6/13 to 4/13 between the immediate pre-pandemic and early pandemic eras, while testing for influenza and respiratory syncytial virus (RSV) in all ARI cases decreased from 12/13 to 9/13. Conversely, the number of centres using multiplex-PCR for high-risk or intensive care unit (ICU)-admitted cases increased from 6/13 to 8/13 during this period. In the late pandemic era, 7/13 centers tested all admitted children for ARIs with multiplex-PCR, and 12/13 tested for influenza and RSV, regardless of disease severity. Five centers continued to test only high-risk or ICU-admitted cases with multiplex-PCR, and one centre did not routinely test even high-risk cases. All 13 centers adopted SARS-CoV-2 testing for all admitted children with ARIs during both the early and late pandemic eras. Figure B shows the total number of non-COVID-19 multiplex-PCR tests performed during the three eras in 7/13 centres for which these data were available. A notable decrease in multiplex-PCR testing was observed from the immediate pre-pandemic to the early pandemic era, followed by a substantial increase in the late pandemic era, surpassing the pre-pandemic levels in all seven centers.

Conclusion(s): Testing practices differed between centers and changed over time, often prioritizing high-risk cases. Interpretation of COVID-19 co-infections and outcomes should account for local testing policies. The notable increase in late-pandemic multiplex-PCR tests suggests a possible rise in pediatric ARI admissions and the resurgence of seasonal respiratory infections.