Performance Assessment of a Rapid Molecular Respiratory Syncytial Virus Point-of-Care Test: A Prospective Community Study in Older Adults.

Background: Respiratory syncytial virus (RSV) causes a substantial burden in older adults. Viral load in RSV-infected adults is generally lower compared to young children, which could result in suboptimal sensitivity of RSV diagnostics. Although the Xpert® Xpress Flu/RSV assay has been used in routine clinical care, its sensitivity to diagnose RSV infection in older adults is largely unknown. We aimed to compare the performance of the Xpert® Xpress Flu/RSV assay with real-time reverse-transcription polymerase chain reaction (RT-PCR) in home-dwelling older adults (≥60 years of age).
Methods: Nasopharyngeal swabs were tested with Xpert® Xpress Flu/RSV and compared to RSV RT-PCR in older adults with acute respiratory tract infections with different levels of disease severity.
Results: We studied 758 respiratory samples from 561 older adults from 2 consecutive RSV seasons. Thirty-five (4.6%) samples tested positive for RSV by at least 1 of the assays, of which 2 samples were negative by Xpert® Xpress Flu/RSV and 3 samples by real-time RT-PCR. The positive percentage agreement (PPA) was 90.9% (95% confidence interval [CI], 76.4%-96.8%) and negative percentage agreement was 99.7% (95% CI, 99.0%-99.9%). Viral loads were low (≤103 copies/mL or cycle threshold value ≥34) in all cases with discordant results for the 2 assays.
Conclusions: The PPA of Xpert® Xpress Flu/RSV compared to routine RT-PCR is high for RSV detection in home-dwelling older adults. The assay is fast and easy to use at the point of care.
Clinical Trials Registration: NCT03621930.
Competing Interests: Potential conflicts of interest. N. A. reports grants and nonfinancial support from European Union’s Horizon 2020 Research and Innovation Programme and EFPIA, during the conduct of the study. O. G. reports personal fees from GSK, outside the submitted work. C. B. reports grants from the European Union, during the conduct of the study; and personal fees from Roche, grants and personal fees from Janssen Pharmaceuticals, and grants from the National Institute of Health Care Research, outside the submitted work. S. C. reports grants and nonfinancial support from the European Union’s Horizon 2020 Research and Innovation Programme and EFPIA, during the conduct of the study. L. J. B. has regular interaction with pharmaceutical and other industrial partners, but has not received personal fees or other personal benefits. He is also the founding chairman of the ReSViNET Foundation. University Medical Centre Utrecht has received major funding (>€100,000 per industrial partner) for investigator-initiated studies from AbbVie, MedImmune, Janssen, the Bill & Melinda Gates Foundation, Nutricia (Danone), and MeMed Diagnostics; major cash or in-kind funding as part of the public-private partnership IMI-funded RESCEU project from GSK, Novavax, Janssen, AstraZeneca, Pfizer, and Sanofi; major funding by Julius Clinical for participating in the INFORM study sponsored by MedImmune; minor funding for participation in trials by Regeneron and Janssen from 2015 to 2017 (total annual estimate <€20,000); and minor funding for consultation and invited lectures by AbbVie, MedImmune, Ablynx, Bavaria Nordic, MabXience, Novavax, Pfizer, and Janssen (total annual estimate <€20,000). All other authors report no potential conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.
(© The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America.)