Evaluation of a fluorescent immunoassay rapid test (Sofia™) for detection of influenza A + B and RSV in a tertiary pediatric setting

• We assess performance of Sofia™ Flu A + B and RSV while compared to viral culture.
• A total of 411 prospective pediatric respiratory samples were included.
• Sensitivity of Sofia™ ranged from 87.7% to 90.9% depending on virus detected.
• Specificity of Sofia™ ranged from 94.7% to 98.9% depending on virus detected.
• Rapid antigen testing still has its utility in high-prevalence settings.

In response to the lack of sensitivity and reproducibility of previously marketed rapid antigen detection tests, a novel fluorescent immunoassay was recently developed. This new assay offers rapidity and automated reading. More characterization of this assay is needed. The aim of this study was to assess diagnostic performance of Sofia influenza A + B and respiratory syncytial virus (RSV) while compared to traditional viral cell culture. A total of 416 respiratory samples were analyzed prospectively with both methods in a tertiary pediatric center. Sensitivity and specificity of the Sofia™ test were 90.0% and 98.0% for influenza A, 90.9% and 98.9% for influenza B, and 87.7% and 94.7% for RSV compared to traditional cell culture. Overall, Sofia influenza A + B and RSV assays performed well in comparison to culture in a pediatric population.