Background: Economic and seasonally-driven pressures for faster, accurate sample testing at reduced costs have resulted in an increased need for highly sensitive and specific assays with high throughput for respiratory illnesses. The PlexPCR^® RespiVirus 11 (beta) assay (SpeeDx, Australia) detects 11 respiratory viral targets in a two-well format, using PlexZymes to enable highly sensitive and efficient qPCR multiplexing (1). Here we evaluated this assay in comparison with the Fast Track Diagnostics Respiratory pathogens 21 (FTD RP21) multiplex qPCR assay.

Material/Methods: PlexPCR^® RespiVirus 11 (beta) assay was evaluated against FTD RP21 assay on 245 retrospective upper and lower respiratory tract samples. Targets common to both assays, Influenza A (FluA), Influenza B (FluB), Rhinoviruses (RhV), Respiratory Syncytial Viruses A/B (RSV), Human metapneumovirus (hMPV), Adenoviruses B/C (AdV (B/C)) and Human parainfluenza viruses 1, 2, 3 4 (HPIV 1-4) were analysed. Discrepant samples were resolved by re-testing with the FTD RP21 assay.

Results: Compared to FTD RP21 assay, the PlexPCR^® RespiVirus 11 (beta) assay had a final sensitivity/specificity of: FluA 92%/99.41%, FluB 100%/99.51%, RSV 100%/100%, RhV 100%/99.12%, hMPV 90%/100%, AdV (B/C) 100%/99.15% and HPIV 1-4 100%/100%. Processing of the 245 samples required 502 wells (5.3 plates) for PlexPCR^® RespiVirus 11 (beta) assay versus 1024 wells (10.6 plates) for FTD RP21 assay.

Conclusions: The PlexPCR^® RespiVirus 11 (beta) assay demonstrated excellent sensitivity and specificity for the detection of 11 respiratory viral targets. In addition the assay is highly multiplexed and could be run in 2 wells versus 4 wells as for the comparator commercial assay, allowing significant gains in increasing throughput and reducing costs.