Introduction
The clinical presentation of various respiratory viral infections is often indistinguishable, yet treatment pathways, isolation protocols, and antiviral therapies differ significantly. This creates a critical need for rapid diagnostic tests that can accurately differentiate between SARS-CoV-2, Influenza A, Influenza B, and Respiratory Syncytial Virus (RSV) at the point of care [1]. This study aimed to evaluate the clinical performance of the reOpenTest COVID-19/Flu A&B/RSV Antigen Combo Test in a real-world, multi-center setting.
Methods
This prospective study enrolled 1,254 consenting patients presenting with signs and symptoms of acute respiratory infection at three hospital-associated clinics. Paired nasopharyngeal swabs were collected from each patient. One swab was tested immediately on-site using the reOpenTest combo test according to the manufacturer's instructions. The second swab was sent to a central laboratory for testing with a CE-IVD/FDA-EUA authorized RT-PCR respiratory panel. Results were analyzed to determine the Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA) of the reOpenTest assay compared to the RT-PCR reference method. All study protocols were approved by the relevant institutional review boards.
Results
The study population included a well-distributed mix of positive cases for all four viral targets. The overall performance of the reOpenTest combo test is summarized in the table below.
Table 1: Overall Performance of reOpenTest Combo Test vs. RT-PCR (N=1,254)
| Virus Target | PPA (Sensitivity) | 95% CI | NPA (Specificity) | 95% CI |
|---|---|---|---|---|
| SARS-CoV-2 | 96.2% | 92.5 - 98.2% | 99.4% | 98.8 - 99.7% |
| Influenza A | 95.8% | 92.1 - 97.9% | 99.8% | 99.3 - 99.9% |
| Influenza B | 97.1% | 93.0 - 98.9% | 99.9% | 99.5 - 100% |
| RSV | 95.5% | 91.5 - 97.8% | 99.1% | 98.4 - 99.5% |
Analysis of performance by study site showed no statistically significant variation in PPA or NPA, indicating high consistency and reproducibility of the test across different user populations and environments.
Discussion
The results of this large, multi-center study demonstrate that the reOpenTest respiratory combo test provides a high level of accuracy for all four targets when compared to the molecular gold standard. The high PPA is particularly noteworthy for an antigen-based assay, suggesting excellent analytical sensitivity. The exceptional consistency of results across the three geographically diverse clinical sites is a critical finding. We attribute this robustness to the underlying manufacturing process. The NomoFlow™ platform, used to produce these tests, ensures extremely low batch-to-batch variability (CV < 3%), which translates directly into the dependable clinical performance observed in this study.
Conclusion
The reOpenTest COVID-19/Flu A&B/RSV Antigen Combo Test is a reliable and accurate tool for the rapid differential diagnosis of common respiratory viruses. Its performance supports its use in clinical settings where timely results are needed to guide patient management.