Comparison of Sofia 2 Respiratory Syncytial Virus Fluorescent Immunoassay to Real-Time Polymerase Chain Reaction Assay in Children Under Two Years Old Hospitalized With Acute Respiratory Illness in Amman, Jordan: A Cross-Sectional Study.

BACKGROUND AND AIMS: Respiratory syncytial virus (RSV) is a leading cause of acute respiratory infection (ARI) in children, particularly in low- and middle-income countries. Rapid diagnosis is important for management and infection control. We aimed to evaluate diagnostic accuracy of Sofia 2 RSV fluorescent immunoassay (FIA) compared to reverse-transcription quantitative PCR (RT-qPCR) in children under 2 years hospitalized with ARI in Amman, Jordan.

METHODS

We conducted a prospective viral surveillance study from January 26, 2020 to March 17, 2020, at Al-Bashir Hospital. Sofia 2 RSV FIA was performed on nasal swabs and compared to RT-qPCR. We calculated sensitivity, specificity, and Cohen's κ with 95% confidence intervals and assessed factors associated with RSV detection by FIA using logistic regression.

RESULTS

Of 458 children enrolled, 356 (77.7%) had RSV detected by RT-qPCR. Sofia 2 RSV FIA demonstrated 76.1% sensitivity (95% CI: 71.3, 80.5%) and 94.1% specificity (95% CI: 87.6, 97.8%) relative to RT-qPCR. Lower RT-qPCR cycle threshold value (inversely related to viral load) was significantly associated with Sofia 2 RSV FIA positivity (aOR = 0.75; 95% CI: 0.70, 0.81; p < 0.001).

CONCLUSION

Sofia 2 RSV FIA demonstrates potential as a rapid diagnostic test in resource-limited settings. Further research on its clinical outcomes and cost-effectiveness could enhance RSV management in children.