(142 days)
The Diagnostic Hybrids, Inc. device, D3 FastPoint L-DFA Respiratory Virus Identification Kit is intended for the qualitative identification of influenza A virus, influenza B virus, respiratory syncytial virus, human metapneumovirus, adenovirus and to screen for the presence of parainfluenza virus types 1, 2, and 3 in nasal and nasopharyngeal swabs and aspirates/washes specimens from patients with signs and symptoms of respiratory infection by direct detection of immunofluorescence using monoclonal antibodies (MAbs).
It is recommended that specimens found to be negative for influenza A virus, influenza B virus, respiratory syncytial virus, adenovirus or parainfluenza viruses after examination of the direct specimen result be confirmed by cell culture. Specimens found to be negative for human metapneumovirus after examination of the direct specimen results should be confirmed by an FDA cleared human metapneumovirus molecular assay. Negative results do not preclude respiratory virus infection and should not be used as the sole basis for diagnosis, treatment or other management decisions.
Performance characteristics for influenza A virus detection and identification were established when influenza A (H3N2) and influenza A (H1N1) were the predominant influenza A strains circulating in the United States. Since influenza strains display antigenic drift and shift from year to year, performance characteristics may vary. If infection with a novel influenza A virus is suspected, based on clinical and epidemiological screening criteria communicated by public health authorities, collect specimens following appropriate infection control precautions and submit 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 D3 FastPoint L-DFA Respiratory Virus Identification Kit uses three blends (each called a "L-DFA Reagent") of viral antigen-specific murine monoclonal antibodies that are directly labeled with either R-PE (influenza A virus, respiratory syncytial virus, and parainfluenza virus) or fluorescein (influenza B virus, metapneumovirus, and adenovirus) for the rapid identification of respiratory viruses in nasal and nasopharyngeal swabs and aspirates from patients with signs and symptoms of respiratory infection.
Kit Components:
- D3 FastPoint L-DFA Influenza A/Influenza B Reagent, 4.0-mL. One dropper bottle containing a mixture of PE-labeled murine monoclonal antibodies directed against influenza A virus antigens and FITC-labeled murine monoclonal antibodies directed against influenza B virus antigens. The buffered, stabilized, aqueous solution contains Evans Blue and propidium iodide as counter-stains and 0.1% sodium azide as preservative.
- D3 FastPoint L-DFA RSV/MPV Reagent, 4.0-mL. One dropper bottle containing a mixture of PE-labeled murine monoclonal antibodies directed against respiratory syncytial virus antigens and FITC-labeled murine monoclonal antibodies directed against metapneumovirus antigens. The buffered, stabilized, aqueous solution contains Evans Blue and propidium iodide as counter-stains and 0.1% sodium azide as preservative.
- D3 FastPoint L-DFA PIV/Adenovirus Reagent, 4.0-mL. One dropper bottle containing a mixture of PE-labeled murine monoclonal antibodies directed against parainfluenza virus types 1, 2, or 3 antigens and FITClabeled murine monoclonal antibodies directed against adenovirus antigens. The buffered, stabilized, aqueous solution contains Evans Blue and propidium iodide as counter-stains and 0.1% sodium azide as preservative.
- 40X PBS Concentrate, 25-mL. One bottle of 40X PBS concentrate containing 4% sodium azide (0.1% sodium azide after dilution to 1X using de-mineralized water).
- Re-suspension Buffer, 6.0-mL. One bottle of a buffered glycerol solution and 0.1% sodium azide.
- D3 FastPoint L-DFA Respiratory Virus Antigen Control Slides, 5-slides. Five individually packaged control slides containing 6 wells with cell culture-derived positive and negative control cells. Each positive well is identified as to the virus infected cells present, i.e., influenza A virus, influenza B virus, respiratory syncytial virus, metapneumovirus, parainfluenza virus, and adenovirus. The negative wells contain noninfected cells. Each slide is intended to be stained only one time.
The cells to be tested are derived from respiratory specimens from patients with signs and symptoms of respiratory infection. The cells are permeabilized and stained concurrently in a liquid suspension format in 3 separate vials, each containing one of the 3 above reagents. After incubating at 35℃ to 37℃ for 5 minutes, the stained cell suspensions are rinsed with 1X PBS. The rinsed cells are pelleted by centrifugation and then re-suspended with the resuspension buffer and loaded onto a specimen slide well. The cells are examined using a fluorescence microscope. Cells infected with influenza A virus, respiratory syncytial virus, or parainfluenza virus types 1, 2 and 3 will exhibit goldenyellow fluorescence due to the PE. Cells infected with influenza B virus, metapnemovirus or adenovirus will exhibit apple-green fluorescence due to the FITC. Non-infected cells will exhibit red fluorescence due to the Evans Blue counter-stain. Nuclei of intact cells will exhibit orange-red fluorescence due to the propidium iodide.
Here's a summary of the acceptance criteria and study details for the D3 FastPoint L-DFA Respiratory Virus Identification Kit, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state pre-defined acceptance criteria (e.g., "Sensitivity must be >X%"). Instead, it presents the results of reproducibility and clinical performance studies, implying that these results met the necessary standards for clearance. The "Reported Device Performance" column reflects the results from the clinical sensitivity and specificity studies presented in Tables 5.10-5.15 (for NP wash/aspirate) and 5.16-5.21 (for NP swab). For analytical performance, the reproducibility and LOD results are provided.
| Criterion Type | Acceptance Criteria (Implicit) | Reported Device Performance (Summary) |
|---|---|---|
| Analytical Performance | ||
| Reproducibility | Consistent detection of viral antigens across different sites and runs. | Influenza A/B Reagent: Total agreement 99.3% (278/280). |
| RSV/hMPV Reagent: Total agreement 100% (280/280). | ||
| HPIV/Adenovirus Reagent: Total agreement 100% (280/280). | ||
| Limit of Detection (LoD) | Detection of specific viral strains at low concentrations. | Flu A: 50 infected cells/mL |
| Flu B: 50 infected cells/mL | ||
| RSV: 100 infected cells/mL | ||
| hMPV A1: 100 infected cells/mL | ||
| Adenovirus: 100 infected cells/mL | ||
| HPIV-1: 100 infected cells/mL | ||
| HPIV-2: 25 infected cells/mL | ||
| HPIV-3: 50 infected cells/mL | ||
| Analytical Reactivity (Inclusivity) | Detection of various strains of targeted viruses. | Detected all tested strains of Influenza A (13), Influenza B (7), RSV (3), hMPV (4), HPIV (3), and Adenovirus (10). |
| Clinical Performance (NP Wash/Aspirate) | Acceptable sensitivity and specificity compared to comparator methods. | Flu A: Sensitivity 84.8%, Specificity 99.5% |
| Flu B: Sensitivity 81.8%, Specificity 100.0% | ||
| RSV: Sensitivity 98.6%, Specificity 99.8% | ||
| Adenovirus: Sensitivity 92.3%, Specificity 100.0% | ||
| HPIV: Sensitivity 92.0%, Specificity 99.3% | ||
| hMPV: Sensitivity 68.8%, Specificity 100.0% | ||
| Clinical Performance (NP Swab) | Acceptable sensitivity and specificity compared to comparator methods. | Flu A: Sensitivity 87.7%, Specificity 99.8% |
| Flu B: Sensitivity 87.9%, Specificity 99.8% | ||
| RSV: Sensitivity 97.5%, Specificity 100.0% | ||
| Adenovirus: Sensitivity 100.0%, Specificity 100.0% (Note: Low prevalence, caution advised) | ||
| HPIV: Sensitivity 92.9%, Specificity 100.0% | ||
| hMPV: Sensitivity 54.5%, Specificity 100.0% |
2. Sample Size Used for the Test Set and Data Provenance
-
Clinical Test Set:
- Total Specimens Evaluated: 1519
- Provenance: Prospectively collected excess remnants of respiratory specimens from symptomatic individuals suspected of respiratory infection.
- Country of Origin: 4 geographically diverse U.S. clinical laboratories.
- Retrospective or Prospective: Prospective studies (January 2009 - March 2009).
- Specific Breakdown for Clinical Performance Tables:
- NP Wash/Aspirate (Sites 1, 2, and 3 combined): Number of specimens varies per virus (e.g., 637 for Flu A, 694 for hMPV).
- NP Swab (Sites 3 and 4 combined): Number of specimens varies per virus (e.g., 689 for Flu A, 675 for hMPV).
-
Analytical Test Set (Reproducibility):
- Sample Size: 5 randomized panel members for each of the 3 panels (Influenza A/B, RSV/hMPV, HPIV/Adenovirus). Each panel was tested daily in two separate runs for 5 days by four different laboratories (40 total runs per virus group). This means 40 replicates for each panel member for a given virus.
- Provenance: Proficiency-level antigen control slides with infected cells.
-
Analytical Test Set (Limit of Detection):
- Sample Size: 10 replicate microscope slides for each dilution level of 8 characterized respiratory virus isolates.
- Provenance: Dilution series of infected model cells.
-
Analytical Test Set (Analytical Reactivity/Inclusivity):
- Sample Size: Low concentration infected cell suspensions (approximately 4% cells infected, 25-50 infected cells) for various viral strains for each of the 3 reagents.
- Provenance: Culture isolates of various influenza A (13 strains), influenza B (7 strains), RSV (3 strains), hMPV (4 strains), HPIV (3 strains), and Adenovirus (10 strains).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number or qualifications of experts used to establish the ground truth for the clinical test set. Instead, it defines "True" positive and "True" negative based on a composite comparator method:
- For Influenza A, Influenza B, RSV, Parainfluenza, and Adenovirus: Direct Specimen Fluorescent Antibody (DSFA) test with an FDA cleared device, and viral culture confirmation of all negatives (as determined by the comparator DSFA test).
- For Human Metapneumovirus (hMPV): DSFA with an FDA cleared device, and confirmation of all negative specimens (as determined by the comparator DSFA test) using a validated hMPV real-time RT-PCR followed by bi-directional sequencing analysis.
4. Adjudication Method for the Test Set
The adjudication method used for establishing the ground truth for the clinical test set was a composite comparator method. This means results from multiple established methods (DSFA, viral culture, and for hMPV, RT-PCR with sequencing) were combined to determine the "true" status of a specimen. There is no mention of a specific expert panel adjudication method like "2+1" or "3+1" for interpreting these comparator results in case of discrepancies; rather, the definition of "true" positive/negative indicates the hierarchy of methods (e.g., positive by DSFA or viral culture is "true" positive).
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
No MRMC comparative effectiveness study was done. This device is a diagnostic kit read by a human using a fluorescence microscope, but the study focuses on the kit's performance against comparator methods, not on human reader improvement with or without AI assistance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is not applicable as the D3 FastPoint L-DFA Respiratory Virus Identification Kit is a diagnostic kit that relies on a human reading the results under a fluorescence microscope. It is not an AI algorithm. The performance presented is of the kit as used by a human.
7. The Type of Ground Truth Used
The ground truth used for the clinical test set was a composite comparator method, which included:
- FDA cleared Direct Specimen Fluorescent Antibody (DSFA) tests
- Viral Culture
- Validated hMPV real-time RT-PCR followed by bi-directional sequencing analysis (for hMPV only)
- NCBI GenBank database matching with acceptable E-values for bi-directional sequencing data.
8. The Sample Size for the Training Set
The document does not explicitly mention a "training set" in the context of machine learning or AI development. This device is a diagnostic reagent kit, not an AI algorithm. The studies conducted are for analytical and clinical validation of the kit itself.
9. How the Ground Truth for the Training Set was Established
As there is no "training set" in the context of this diagnostic kit, this question is not applicable. The ground truth for the comparator methods was established using established laboratory techniques and FDA-cleared devices, as described in point 7.
§ 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.