(169 days)
The ePlex® Respiratory Pathogen (RP) Panel is a multiplexed nucleic acid in vitro diagnostic test intended for use on the ePlex® Instrument for the simultaneous qualitative detection and identification of multiple respiratory viral and bacterial nucleic acids in nasopharyngeal swabs (NPS) obtained from individuals exhibiting signs and symptoms of respiratory tract infection.
The following virus types, subtypes, and bacteria are identified using the ePlex RP Panel: adenovirus, coronavirus, human metapneumovirus, human rhinovirus/enterovirus, influenza A, influenza A H1, influenza A H1-2009, influenza A H3, influenza B, parainfluenza virus 1, parainfluenza virus 2, parainfluenza virus 3, parainfluenza virus 4, respiratory syncytial virus (RSV) A, respiratory syncytial virus (RSV) B, Chlamydia pneumoniae, and Mycoplasma pneumoniae.
The detection and identification of specific viral and bacterial nucleic acids from individuals exhibiting signs and/or symptoms of respiratory tract infection aids in the diagnosis of respiratory infection when used in conjunction with other clinical and epidemiological information. The results of this test should not be used as the sole basis for diagnosis, treatment, or other patient management decisions.
Negative results in the setting of a respiratory illness may be due to infection with pathogens that are not detected by this test, or lower respiratory tract infection that may not be detected by a nasopharyngeal swab specimen. Positive results do not rule out co-infection with other organisms; the organism(s) detected by the ePlex RP Panel may not be the definite cause of disease. Additional laboratory testing (e.g. bacterial and viral culture, immunofluorescence, and radiography) may be necessary when evaluating a patient with possible respiratory tract infection.
Due to the genetic similarity between human rhinovirus and enterovirus, the ePlex RP Panel cannot reliably differentiate them. If differentiation is required, an ePlex RP Panel positive human rhinovirus/enterovirus result should be followed-up using an alternative method (e.g., cell culture or sequence analysis).
Performance characteristics for influenza A were established when influenza A H1-2009 and A H3 were the predominant influenza A viruses in circulation. Performance of detecting influenza A may vary if other influenza A strains are circulating or a novel influenza A virus emerges. 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 control precautions for novel virulent influenza viruses and sent to state or local health departments for testing. Viral culture should not be attempted in these cases unless a BSL-3+ facility is available to receive and culture specimens.
The ePlex RP Panel is an automated qualitative nucleic acid multiplex in vitro diagnostic test for simultaneous detection and identification of multiple respiratory viral and bacterial nucleic acids in nasopharyngeal swabs (NPS). The test is able to detect 15 respiratory viral targets and 2 bacterial targets as summarized in the table below. This test is performed on the ePlex Instrument.
The ePlex Instrument automates all aspects of nucleic acid testing including extraction, amplification, and detection, combining electrowetting and GenMark's eSensor® technology in a single-use cartridge. eSensor technology is based on the principles of competitive DNA hybridization and electrochemical detection. which is highly specific and is not based on fluorescent or optical detection.
Electrowetting, or digital microfluidics, uses electrical fields to directly manipulate discrete droplets on the surface of a hydrophobically coated printed circuit board (PCB). Sample and reagents are moved in a programmable fashion in the ePlex cartridge to complete all portions of the sample processing from nucleic acid extraction to detection.
A sample is loaded onto the ePlex cartridge and nucleic acids are extracted and purified from the specimen via magnetic solid phase extraction. For RNA targets, a reverse transcription step is performed to generate complementary DNA from the RNA. followed by PCR to amplify the targets. Exonuclease digestion creates single-stranded DNA in preparation for eSensor detection.
The target DNA is mixed with ferrocene-labeled signal probes that are complementary to the specific targets on the panel. Target DNA hybridizes to its complementary signal probe and capture probes, which are bound to gold-plated electrodes. The presence of each target is determined by voltammetry which generates specific electrical signals from the ferrocenelabeled signal probe.
The acceptance criteria and study proving the device meets them are summarized below. It should be noted that this document focuses on the ePlex Respiratory Pathogen (RP) Panel, which is an in vitro diagnostic test, not an AI medical device. Therefore, several requested sections (e.g., number of experts for ground truth, adjudication method, MRMC study, sample size for training set) are not applicable as they pertain to image-based AI studies.
1. Table of Acceptance Criteria and Reported Device Performance
For an in vitro diagnostic test like the ePlex RP Panel, acceptance criteria are typically defined by performance metrics such as Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA) with a comparator method. The study aims to demonstrate that the device performs equivalently to or better than established methods.
| Organism | Acceptance Criteria (Implicit) PPA | Reported PPA (95% CI) - Fresh Samples | Reported PPA (95% CI) - Frozen Samples | Reported PPA (95% CI) - Retrospective Samples | Acceptance Criteria (Implicit) NPA | Reported NPA (95% CI) - Fresh Samples | Reported NPA (95% CI) - Frozen Samples | Reported NPA (95% CI) - Retrospective Samples |
|---|---|---|---|---|---|---|---|---|
| Adenovirus | High (e.g., >80-90%) | 75.0 (40.9-92.9) | 90.6 (79.7-95.9) | 98.2 (90.6-99.7) | High (e.g., >95%) | 99.2 (98.0-99.7) | 98.7 (98.1-99.1) | 99.0 (97.4-99.6) |
| Coronavirus | High | 100 (64.6-100) | 80.9 (72.6-87.2) | 87.7 (81.2-92.2) | High | 99.8 (98.9-100) | 99.3 (98.8-99.6) | 100 (98.8-100) |
| Human Metapneumovirus | High | --- (0/0 prevalence) | 94.7 (88.9-97.5) | 71.4 (35.9-91.8) | High | 100 (99.3-100) | 99.7 (99.3-99.9) | 100 (99.1-100) |
| Human Rhinovirus/Enterovirus | High | 96.2 (92.3-98.1) | 94.3 (91.3-96.4) | 90.2 (77.5-96.1) | High | 96.3 (93.7-97.9) | 95.6 (94.5-96.5) | 95.5 (93.0-97.1) |
| Influenza A | High | --- (0/0 prevalence) | 95.5 (89.9-98.1) | 91.5 (83.4-95.8) | High | 100 (99.3-100) | 99.8 (99.4-99.9) | 100 (99.0-100) |
| Influenza A H1 | High | --- (0/0 prevalence) | 0/0 (no prevalence) | --- (0/0 prevalence) | High | 100 (99.3-100) | 100 (99.8-100) | 100 (99.1-100) |
| Influenza A H1-2009 | High | --- (0/0 prevalence) | 98.6 (92.4-99.8) | 87.1 (71.1-94.9) | High | 100 (99.3-100) | 99.7 (99.3-99.9) | 100 (99.1-100) |
| Influenza A H3 | High | --- (0/0 prevalence) | 91.9 (78.7-97.2) | 88.2 (76.6-94.5) | High | 100 (99.3-100) | 100 (99.8-100) | 100 (99.0-100) |
| Influenza B | High | 100 (20.7-100) | 89.2 (79.4-94.7) | 100 (20.7-100) | High | 99.8 (98.9-100) | 99.8 (99.5-99.9) | 100 (99.1-100) |
| Parainfluenza Virus 1 | High | 100 (20.7-100) | 95.8 (79.8-99.3) | 89.6 (77.8-95.5) | High | 100 (99.3-100) | 99.9 (99.7-100) | 99.7 (98.6-100) |
| Parainfluenza Virus 2 | High | 92.3 (66.7-98.6) | 100 (70.1-100) | 90.2 (79.0-95.7) | High | 99.8 (98.9-100) | 99.9 (99.7-100) | 100 (99.0-100) |
| Parainfluenza Virus 3 | High | 100 (56.6-100) | 90.4 (83.2-94.7) | 100 (34.2-100) | High | 100 (99.2-100) | 99.7 (99.4-99.9) | 100 (99.1-100) |
| Parainfluenza Virus 4 | High | 100 (43.9-100) | 100 (56.6-100) | 90.0 (69.9-97.2) | High | 99.0 (97.7-99.6) | 99.9 (99.6-100) | 100 (99.1-100) |
| RSV A | High | 88.9 (56.5-98.0) | 87.1 (71.1-94.9) | 92.6 (76.6-97.9) | High | 100 (99.2-100) | 99.9 (99.7-100) | 100 (99.1-100) |
| RSV B | High | 90.0 (59.6-98.2) | 94.2 (87.1-97.5) | 95.5 (78.2-99.2) | High | 100 (99.2-100) | 99.9 (99.6-100) | 100 (99.1-100) |
| Chlamydia pneumoniae | High | --- (0/0 prevalence) | 40.0 (11.8-76.9) | 100 (20.7-100) | High | 100 (99.3-100) | 99.9 (99.7-100) | 100 (99.1-100) |
| Mycoplasma pneumoniae | High | 100 (43.9-100) | 80.0 (37.6-96.4) | 100 (64.6-100) | High | 99.8 (98.9-100) | 99.9 (99.7-100) | 100 (99.1-100) |
Note: The document does not explicitly state numerical acceptance criteria. The "Implicit Acceptance Criteria" are inferred as generally high agreement rates required for diagnostic tests to demonstrate substantial equivalence to predicate devices.
2. Sample Sizes Used for the Test Set and Data Provenance
- Prospective Clinical Samples:
- Sample Size: 2462 evaluable samples collected.
- Data Provenance: Prospectively-collected at 8 clinical sites (presumably in the USA, as this is an FDA submission).
- Collection Phases:
- Phase 1: March 2013 - August 2014 (1951 samples, frozen)
- Phase 2: September 2016 - October 2016 (511 samples, fresh)
- Patient Population: Individuals of all ages and genders exhibiting signs and/or symptoms of respiratory tract infection.
- Retrospective Clinical Samples (to supplement positives for low prevalence targets):
- Sample Size: 446 evaluable samples.
- Data Provenance: Retrospectively collected from 6 sites (presumably in the USA), previously tested positive for one or more target organisms during standard-of-care (SOC) testing. Stored frozen.
- Contrived Samples (to supplement low prevalence targets):
- Sample Size: 327 contrived samples (104 positive for one or more low prevalence organisms, 223 negative for contrived organisms).
- Data Provenance: Lab-generated by spiking viral/bacterial cultures into a natural clinical matrix (pooled, negative nasopharyngeal swab in VTM samples).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
Not applicable. This is an in vitro diagnostic device study, not an AI medical device study involving expert interpretation of images or clinical data. Ground truth was established by laboratory methods.
4. Adjudication Method for the Test Set
Not applicable in the typical sense of expert adjudication for AI interpretation. Discrepant results between the ePlex RP Panel and the comparator method were investigated using PCR/sequencing (as detailed in footnotes of Tables 7, 8, 10, 12, and 13). This serves as a molecular adjudication method to refine the ground truth.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is relevant for evaluating the impact of AI assistance on human reader performance, which doesn't apply to this molecular diagnostic device.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, the performance study effectively evaluates the ePlex RP Panel in a standalone manner. The device automates nucleic acid testing, and its results are compared against a laboratory-based (molecular) comparator method. There is no "human-in-the-loop" component in the interpretation or direct performance of the ePlex RP Panel that would necessitate studying its effect on human readers.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The ground truth for the clinical performance evaluation was established using:
- FDA-cleared multiplexed molecular respiratory pathogen panels (serving as the primary comparator method).
- Analytically validated PCR tests with bi-directional sequencing for confirmation, especially for RSV subtypes and to resolve discrepancies.
For analytical studies (LoD, inclusivity, specificity), the ground truth was based on known concentrations of quantified reference strains/isolates.
8. The Sample Size for the Training Set
Not applicable. This is not an AI/machine learning study where a distinct "training set" is used to develop an algorithm. The device's design and analytical parameters are established through laboratory development and validation, not through learning from a large, labeled dataset in the way an AI model would be trained.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no "training set" in the context of this molecular diagnostic device. The device's reagents and detection mechanisms are designed based on known genetic sequences of the target pathogens.
§ 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.