Enhanced RSV Infection Detection via Weekly Sampling and Biannual Serology

Overview

This longitudinal birth cohort study demonstrated that combining weekly RT-qPCR nasal swab testing with biannual serological assessments significantly increases detection sensitivity of respiratory syncytial virus (RSV) infections. The integrated approach revealed higher cumulative incidence and infection rates compared to RT-qPCR testing alone, without bias from sample adherence levels.

Background

Accurate detection of RSV infections in cohort studies is challenged by incomplete adherence to frequent sampling, which can underestimate disease burden. RT-qPCR testing of nasal swabs is sensitive but relies on high participant compliance, while serological assays can detect infections retrospectively but lack precise timing. Combining these methods may improve infection ascertainment and provide better insights into RSV epidemiology and immune development in early childhood.

Data Highlights

Key Findings

• Using a mixed-effects classification and regression tree, a log10 increase in RSV pre-fusion F IgG > 0.32 or IgA > 0.20 was identified as indicative of RSV infection.
• Combining RT-qPCR nasal swab testing with biannual serology increased RSV cumulative incidence from 49% to 75% (P < .001).
• Incidence rate increased from 0.33 to 0.71 infections per child-year when serology was added (P < .001).
• RSV incidence rates using combined methods did not differ significantly from those in participants with ≥90% weekly sample adherence, indicating robustness of the combined approach.
• Serological assessments enabled detection of infections missed by RT-qPCR due to incomplete weekly sampling or asymptomatic cases.

Clinical Implications

Incorporating biannual serological testing alongside frequent RT-qPCR nasal swabs enhances RSV infection detection in longitudinal pediatric cohorts, capturing both symptomatic and asymptomatic cases. This integrated approach reduces bias from variable sample adherence and improves accuracy in estimating RSV incidence, which is critical for evaluating vaccine effectiveness and understanding immune development.

Conclusion

The combined use of weekly RT-qPCR nasal sampling and biannual serological assessments substantially improves detection sensitivity for RSV infections in young children, providing a more complete understanding of RSV epidemiology in birth cohorts.

References

1. PREVAIL Cohort Study Group 2024 -- Enhancing Detection Sensitivity of Respiratory Syncytial Virus Infections in Longitudinal Research