Objective:

To evaluate associations between respiratory viral detection and clinical outcomes in children with febrile seizures (FS).

Approach:

• Study Design: Retrospective analysis of children aged 6–60 months with FS who underwent multiplex respiratory virus RT-PCR in a tertiary pediatric emergency department from April 2023 to March 2025.
• Statistical Analysis: Logistic regression was used to assess associations of individual viruses and viral co-detection with risks of complex febrile seizures (CFS) and hospitalization, adjusting for various covariates.

Key Findings:

• Among 558 children, 95 (17.0%) had CFS.
• Parainfluenza virus (PIV) was associated with lower odds of CFS (adjusted OR 0.38, 95% CI 0.16 to 0.89).
• Seasonal coronaviruses were associated with lower odds of CFS (adjusted OR 0.33, 95% CI 0.12 to 0.89).
• PIV was associated with lower odds of hospitalization (adjusted OR 0.37, 95% CI 0.17 to 0.80).
• Respiratory syncytial virus (RSV) was associated with lower odds of hospitalization (adjusted OR 0.32, 95% CI 0.13 to 0.78).
• Viral co-detection occurred in 47.8%, and each additional virus was associated with lower odds of CFS (OR 0.62, 95% CI 0.44 to 0.88) and hospitalization (OR 0.66, 95% CI 0.49 to 0.90).

Interpretation:

Detection of certain respiratory viruses and viral co-detection was associated with lower odds of CFS and hospitalization, indicating the need for cautious interpretation of multiplex RT-PCR results.

Limitations:

• Residual confounding and selection bias related to the retrospective design.
• Clinician-directed testing may have influenced results.

Conclusion:

The study emphasizes the importance of cautious interpretation of multiplex RT-PCR results in relation to clinical presentation.