(255 days)
The Verigene® Respiratory Pathogens Flex Nucleic Acid Test (RP Flex) is a multiplexed qualitative test intended for the simultaneous detection and identification of multiple viral and bacterial nucleic acids in nasopharyngeal swabs (NPS) obtained from individuals suspected of respiratory tract infection. The test is performed on the automated Verigene System utilizing reverse transcription (RT), polymerase chain reaction (PCR), and microarray hybridization to detect gene sequences of the following organism types and subtypes:
| Viruses | Bacteria |
|---|---|
| Adenovirus | Bordetella parapertussis/bronchiseptica |
| Human Metapneumovirus | Bordetella holmesii |
| Influenza A | Bordetella pertussis |
| Influenza A (Subtype H1) | |
| Influenza A (Subtype H3) | |
| Influenza B | |
| Parainfluenza 1 | |
| Parainfluenza 2 | |
| Parainfluenza 3 | |
| Parainfluenza 4 | |
| Respiratory Syncytial Virus A | |
| Respiratory Syncytial Virus B | |
| Rhinovirus |
Detecting and identifying specific viral and bacterial nucleic acids from individuals exhibiting signs and symptoms of respiratory infection aids in the diagnosis of respiratory infection with other clinical and laboratory findings. The results of this test should not be used as the sole basis for diagnosis, treatment, or patient management decisions.
Negative results in the presence of a respiratory illness do not preclude respiratory infection and may be due to infection with pathogens that are not detected by this test or lower respiratory tract infection that is not detected by an NPS specimen. Conversely, positive results do not rule-out infection with organisms not detected by RP Flex. The agent(s) detected may not be the definite cause of disease. The use of additional laboratory testing and clinical presentation may be necessary to establish a final diagnosis of respiratory infection.
Clinical evaluation indicates a lower sensitivity specific to RP Flex for the detection of Rhinovirus. If infection with Rhinovirus is suspected, negative samples should be confirmed using an alternative method.
Performance characteristics for Influenza A were established when Influenza A/H1 (2009 Pandemic) and A/H3 were the predominant Influenza A viruses in circulation. RP Flex may not detect novel Influenza A strains. If infection with a novel Influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection used specifically for novel virulent influenza viruses and sent to appropriate health authorities for testing. Viral culture should not be attempted in these cases unless a biosafety level (BSL) 3+ facility is available to receive and culture specimens.
The Verigene Respiratory Pathogens Flex Nucleic Acid Test (RP Flex) is a molecular assay that relies on detection of specific nucleic acid targets in a microarray format. For each of the bacterial or viral nucleic acid sequences detected by RP Flex, unique Capture and Mediator oligonucleotides are used, with gold nanoparticle probe-based endpoint detection. The Capture oligonucleotides are covalently bound to the microarray substrate and hybridize to a specific portion of the nucleic acid targets. The Mediator oligonucleotides have a region that binds to a different portion of the same nucleic acid targets and also have a sequence that allows binding of a gold nanoparticle probe. Specific silver enhancement of the bound gold nanoparticle probes at the capture sites results in gold-silver aggregates that scatter light with high efficiency and provide accurate detection of target capture.
The RP Flex test is performed on the Verigene System, a "sample-to-result," fully automated, bench-top molecular diagnostics workstation. The System enables automated nucleic acid extraction from nasopharyngeal swabs (NPS) and detection of analyte-specific target nucleic acids. The Verigene System consists of two components: the Verigene Reader and the Verigene Processor SP.
The Reader is the Verigene System's user interface and serves as the central control unit for all aspects of test processing, automated imaging, and result generation using a touch-screen control panel and a barcode scanner. The Verigene Processor SP executes the test procedure, automating the steps of (1) Sample Preparation and Target Amplification – cell lysis and magnetic bead-based bacterial and viral nucleic acid isolation and amplification, and (2) Hybridization- detection and identification of analyte-specific nucleic acid in a microarray format by using gold nanoparticle probe-based technology. Once the specimen is loaded by the operator, all other fluid transfer steps are performed by an automated pipette that transfers reagents between wells of the trays and finally loads the specimen into the Test Cartridge for hybridization. Single-use disposable test consumables and a self-contained Verigene Test Cartridge are used for each sample tested with the RP Flex assay.
To obtain the test results after test processing is complete, the user removes the Test Cartridge from the Processor SP, and inserts the substrate holder into the Verigene Reader for analysis. Light scatter from the capture spots is imaged by the Verigene Reader and intensities from the microarray spots are used to make a determination regarding the presence (Detected) or absence (Not Detected) of a targeted nucleic acid sequence/analyte. This determination is made by means of software-based decision algorithm resident in the Verigene Reader.
{
"1. A table of acceptance criteria and the reported device performance": {
"Influenza A": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "98.3% (58/59) (91.0-99.7)",
"Negative Percent Agreement (95% CI)": "99.4% (2121/2134) (99.0-99.6)"
}
},
"Influenza A subtype H1": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "97.8% (45/46) (88.7-99.6)",
"Negative Percent Agreement (95% CI)": "99.7% (2138/2144) (99.4-99.9)"
}
},
"Influenza A subtype H3": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "100% (13/13) (77.2-100)",
"Negative Percent Agreement (95% CI)": "99.8% (2173/2177) (99.5-99.9)"
}
},
"Influenza B": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "98.0% (49/50) (89.5-99.6)",
"Negative Percent Agreement (95% CI)": "99.6% (2139/2147) (99.3-99.8)"
}
},
"RSV A": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "100% (17/17) (81.6-100)",
"Negative Percent Agreement (95% CI)": "99.9% (2150/2153) (99.6-99.9)"
}
},
"RSV B": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "100% (173/173) (97.8-100)",
"Negative Percent Agreement (95% CI)": "98.8% (1973/1997) (98.2-99.2)"
}
},
"Parainfluenza 1": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "90.0% (27/30) (74.4-96.5)",
"Negative Percent Agreement (95% CI)": "99.9% (2165/2167) (99.7-100)"
}
},
"Parainfluenza 2": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "92.3% (12/13) (66.7-98.6)",
"Negative Percent Agreement (95% CI)": "99.9% (2181/2184) (99.6-99.9)"
}
},
"Parainfluenza 3": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "82.4% (14/17) (59.0-93.8)",
"Negative Percent Agreement (95% CI)": "99.9% (2177/2180) (99.6-99.9)"
}
},
"Parainfluenza 4": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "79.2% (19/24) (59.3-90.8)",
"Negative Percent Agreement (95% CI)": "99.8% (2169/2173) (99.5-99.9)"
}
},
"Adenovirus": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "86.0% (49/57) (74.7-92.7)",
"Negative Percent Agreement (95% CI)": "97.2% (2081/2140) (96.5-97.9)"
}
},
"Human Metapneumovirus (hMPV)": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "100% (46/46) (92.3-100)",
"Negative Percent Agreement (95% CI)": "99.7% (2145/2151) (99.4-99.9)"
}
},
"Rhinovirus": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "81.9% (407/497) (78.3-85.0)",
"Negative Percent Agreement (95% CI)": "97.1% (1578/1625) (96.2-97.8)"
}
},
"Bordetella parapertussis/bronchiseptica": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "100% (2/2) (34.2-100)",
"Negative Percent Agreement (95% CI)": "99.9% (2290/2291) (99.8-100)"
}
},
"Bordetella pertussis": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "100% (8/8) (67.6-100)",
"Negative Percent Agreement (95% CI)": "99.9% (2187/2189) (99.7-100)"
}
},
"Bordetella holmesii": {
"Performance Criteria": "Positive Agreement ≥ 90%, Negative Agreement ≥ 95%",
"Reported Performance (All specimens)": {
"Positive Percent Agreement (95% CI)": "100% (1/1) (20.6-100)",
"Negative Percent Agreement (95% CI)": "100% (2305/2305) (99.8-100)"
}
}
},
"2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)": {
"Total specimens enrolled": 3299,
"Specimens included in performance analysis": 3266,
"Specimen types and provenance": {
"Prospectively-collected fresh specimens": {
"Count": 1069,
"Type": "Prospective"
},
"Prospectively-collected frozen specimens": {
"Count": 1317,
"Type": "Prospective"
},
"Retrospectively-collected frozen specimens": {
"Count": 520,
"Type": "Retrospective"
},
"Contrived frozen specimens": {
"Count": 360,
"Type": "Contrived"
}
},
"Country of Origin": "Not explicitly stated, but implies U.S. due to FDA submission."
},
"3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)": "Not specified in the provided text. The ground truth was established by comparing to an FDA-cleared molecular respiratory panel and/or PCR amplification followed by confirmatory bi-directional sequencing.",
"4. Adjudication method (e.g. 2+1, 3+1, none) for the test set": "The method of adjudication for discrepancies between the predicate and PCR/sequencing results is not explicitly detailed. The comparison was made against a 'composite of an FDA-cleared molecular respiratory panel and analytically validated PCR with bi-directional sequencing', implying a reference standard was used for ground truth, but the steps for resolving conflicting results among these methods are not described.",
"5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance": "Not applicable. This is a standalone diagnostic device, not an AI-assisted human reader study.",
"6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done": "Yes, a standalone performance study was conducted. The clinical performance characteristics were determined by comparing the device's results to a composite reference method (FDA-cleared molecular respiratory panel and/or PCR amplification with bi-directional sequencing). The device is described as an 'automated Verigene System' which implies a standalone algorithm making the detection calls.",
"7. The type of ground truth used (expert concensus, pathology, outcomes data, etc)": "A composite reference standard was used as ground truth: an FDA-cleared molecular respiratory panel and/or PCR amplification followed by confirmatory bi-directional sequencing.",
"8. The sample size for the training set": "The document does not explicitly state a 'training set' size for a machine-learning model. This is a molecular diagnostic assay, and its development would typically involve analytical testing (LoD, inclusivity, exclusivity, etc.) rather than a 'training set' in the AI sense. The analytical inclusivity study used a comprehensive panel of 108 strains, and additional 28 strains from the LoD study, making a total of 136 strains for analytical inclusivity tests.",
"9. How the ground truth for the training set was established": "For analytical studies (LoD, inclusivity, exclusivity), the 'ground truth' was based on known concentrations of characterized viral and bacterial strains (TCID50/mL or CFU/mL) in simulated NPS. For inclusivity, identification of the strains was confirmed from their source (e.g., ATCC, Zeptometrix, IRR) and in some cases, further confirmed by quantitative TaqMan real-time PCR or PCR/bi-directional sequencing."
}
§ 866.3980 Respiratory viral panel multiplex nucleic acid assay.
(a)
Identification. A respiratory viral panel multiplex nucleic acid assay is a qualitative in vitro diagnostic device intended to simultaneously detect and identify multiple viral nucleic acids extracted from human respiratory specimens or viral culture. The detection and identification of a specific viral nucleic acid from individuals exhibiting signs and symptoms of respiratory infection aids in the diagnosis of respiratory viral infection when used in conjunction with other clinical and laboratory findings. The device is intended for detection and identification of a combination of the following viruses:(1) Influenza A and Influenza B;
(2) Influenza A subtype H1 and Influenza A subtype H3;
(3) Respiratory Syncytial Virus subtype A and Respiratory Syncytial Virus subtype B;
(4) Parainfluenza 1, Parainfluenza 2, and Parainfluenza 3 virus;
(5) Human Metapneumovirus;
(6) Rhinovirus; and
(7) Adenovirus.
(b)
Classification. Class II (special controls). The special controls are:(1) FDA's guidance document entitled “Class II Special Controls Guidance Document: Respiratory Viral Panel Multiplex Nucleic Acid Assay;”
(2) For a device that detects and identifies Human Metapneumovirus, FDA's guidance document entitled “Class II Special Controls Guidance Document: Testing for Human Metapneumovirus (hMPV) Using Nucleic Acid Assays;” and
(3) For a device that detects and differentiates Influenza A subtype H1 and subtype H3, FDA's guidance document entitled “Class II Special Controls Guidance Document: Testing for Detection and Differentiation of Influenza A Virus Subtypes Using Multiplex Nucleic Acid Assays.” See § 866.1(e) for the availability of these guidance documents.