(227 days)
- The cobas® Influenza A/B & RSV Nucleic Acid Test for Use on the cobas® Liat System (cobas® Liat Influenza A/B & RSV) is an automated multiplex real-time RT-PCR assay for the rapid in vitro qualitative detection and discrimination of influenza A virus, influenza B virus and respiratory syncytial virus (RSV) RNA in nasopharyngeal swab specimens from patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors. The test is intended for use as an aid in the diagnosis and differentiation of influenza B, and RSV in humans and is not intended to detect influenza C.
Negative results do not preclude influenza virus or RSV infection and should not be used as the sole basis for treatment or other patient management decisions. Conversely, positive results do not ruleout bacterial infection or co-infection with other viruses. The agent detected may not be the definite cause of disease.
Performance characteristics for influenza A were established during the 2013-2014 and the 2014-2015 influenza seasons when influenza A/H3 and A/H1N1 pandemic were the predominant influenza A viruses in circulation. When other influenza A viruses are emerging, performance characteristics may vary.
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 department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
- The cobas® Influenza A/B & RSV Quality Control Kit contains External Controls for use with the cobas® Liat Influenza A/B & RSV assay. External Controls are run during the Add cobas® Liat Influenza A/B & RSV Tube Lot procedure. Additional External Controls should be tested in accordance with local, state, federal and/or accrediting organization requirements as applicable.
The cobas Liat Influenza A/B & RSV Nucleic Acid Test for Use on the cobas Liat System ("cobas" Liat Influenza A/B & RSV assay") is a rapid, automated in vitro diagnostic test for the qualitative detection of influenza A, influenza B, and RSV RNA in nasopharyngeal swab (NPS) specimens eluted in viral transport media.
The assay targets a well-conserved region of the matrix gene of influenza A (Inf A target), the non-structural protein gene of influenza B (Inf B target), and the matrix gene of RSV (RSV target). An Internal Process Control (IPC) is also included. The IPC is present to control for adequate processing of the target viruses and to monitor the presence of inhibitors in the sample preparation and RT-PCR.
The assay utilizes a single-use disposable cobas® Liat Tube that holds the sample purification and PCR reagents, and hosts the sample preparation and PCR processes. The cobas Liat Tube uses a flexible tube as a sample vessel. It contains all required unit dose reagents pre-packed in tube segments, separated by peelable seals, in the order of reagent use.
The cobas "Liat System automates and integrates sample purification, nucleic acid amplification, and detection of the target sequence in biological samples. The cobas Liat System performs all assay steps from clinical sample and reports assay result automatically. During the testing process. multiple sample processing actuators of the cobas " Liat System compress the cobas" Liat Tube to selectively release reagents from tube segments, move the sample from one segment to another, and control reaction volume, temperature, and time to conduct sample preparation, nucleic acid extraction, target enrichment, inhibitor removal, nucleic acid elution and real-time PCR. An embedded microprocessor controls and coordinates the actions of these sample processors to perform all required assay processes within the closed cobas Liat Tube.
Positive and negative controls are provided in the cobas® Influenza A/B & RSV Quality Control Kit. The positive control comprises inactivated Influenza B and RSV virus in a dried format. The negative control comprises Universal Transport Media (UTM).
To perform the cobas Liat Influenza A/B & RSV assay, an operator first collects a nasopharyngeal swab and places the swab into UTM. The operator transfers the sample into cobas " Liat Influenza A/B & RSV assay tube using a transfer pipette, and scans the tube barcode to identify the test and the sample barcode to code the sample ID with the assay run on the cobas® Liat System. The cobas® Liat Tube is then inserted into the cobas® Liat System. The system performs all the test steps and outputs interpreted results (e.g. Influenza A Detected, Influenza B Not Detected, RSV Not Detected) in ~20 minutes. A report of the interpreted results can be viewed on the cobas " Liat System's LCD screen, and printed directly through a USB or network connected printer. No reagent preparation or additional steps are required other than adding the sample to the cobas Liat Tube. Because all the reagents are contained within the cobas Liat Tube and no sample or reagent needs to be removed from the tube, crosscontamination between samples is minimized.
The results are interpreted by the cobas Liat System software from measured fluorescent signals and real time curve recognition algorithm. All possible final test results are described below.
Here's a breakdown of the acceptance criteria and study details for the cobas® Liat Influenza A/B & RSV Nucleic Acid Test, based on the provided document:
1. Table of Acceptance Criteria & Reported Device Performance
The document doesn't explicitly lay out "acceptance criteria" in a single, aggregated table with pass/fail marks. Instead, it presents performance data for various analytical and clinical studies. For the clinical studies, it provides percentage agreements and confidence intervals. The "acceptance criteria" can be inferred from the reported performance, implying that these values were considered acceptable by the FDA for substantial equivalence.
Here's a table summarizing the key performance metrics from the study. For acceptance criteria, we'll assume that the reported performance figures met the internal thresholds set by the manufacturer and deemed sufficient by the FDA for 510(k) clearance.
Inferred Acceptance Criteria / Reported Performance for cobas® Liat Influenza A/B & RSV Assay
| Category / Metric | Inferred Acceptance Criteria (e.g., "≥ X%") | Reported Device Performance (with 95% CI where available) |
|---|---|---|
| Analytical Performance | ||
| Reproducibility | ||
| Influenza A - Agreement w/ expected result (Negative) | Highly Accurate (e.g., 100%) | 91/91 (100.0%) [96.0% - 100.0%] |
| Influenza A - Agreement w/ expected result (High Negative) | Highly Accurate (e.g., ≥95%) | 88/90 (97.8%) [92.3% - 99.4%] |
| Influenza A - Agreement w/ expected result (Low Positive) | Highly Accurate (e.g., 100%) | 90/90 (100.0%) [95.9% - 100.0%] |
| Influenza A - Agreement w/ expected result (Moderate Positive) | Highly Accurate (e.g., 100%) | 90/90 (100.0%) [95.9% - 100.0%] |
| Influenza A - Total Agreement | Highly Accurate (e.g., ≥99%) | 900/902 (99.8%) [99.2% - 99.9%] |
| Influenza B - Agreement w/ expected result (Negative) | Highly Accurate (e.g., 100%) | 91/91 (100.0%) [96.0% - 100.0%] |
| Influenza B - Agreement w/ expected result (High Negative) | Highly Accurate (e.g., ≥95%) | 90/91 (98.9%) [94.0% - 99.8%] |
| Influenza B - Agreement w/ expected result (Low Positive) | Highly Accurate (e.g., 100%) | 89/89 (100.0%) [95.9% - 100.0%] |
| Influenza B - Agreement w/ expected result (Moderate Positive) | Highly Accurate (e.g., 100%) | 90/90 (100.0%) [95.9% - 100.0%] |
| Influenza B - Total Agreement | Highly Accurate (e.g., ≥99%) | 901/902 (99.9%) [99.4% - 100.0%] |
| RSV - Agreement w/ expected result (Negative) | Highly Accurate (e.g., 100%) | 91/91 (100.0%) [96.0% - 100.0%] |
| RSV - Agreement w/ expected result (High Negative) | Highly Accurate (e.g., 100%) | 90/90 (100.0%) [95.9% - 100.0%] |
| RSV - Agreement w/ expected result (Low Positive) | Highly Accurate (e.g., ≥95%) | 90/91 (98.9%) [94.0% - 99.8%] |
| RSV - Agreement w/ expected result (Moderate Positive) | Highly Accurate (e.g., 100%) | 90/90 (100.0%) [95.9% - 100.0%] |
| RSV - Total Agreement | Highly Accurate (e.g., ≥99%) | 901/902 (99.9%) [99.4% - 100.0%] |
| Limit of Detection (LOD) | Lowest detectable concentration ≥95% of time | Influenza A: 2.0 × 10^-2 - 2.0 × 10^-3 TCID50/mL |
| Influenza B: 2.0 × 10^-3 - 4.0 × 10^-3 TCID50/mL | ||
| RSV: 4.0 × 10^-1 TCID50/mL | ||
| Analytical Specificity (Reactivity) | 100% detection of tested strains | Detected all 28 Influenza A, 15 Influenza B, and 7 RSV strains tested. |
| Analytical Specificity (Cross-reactivity) | 0% cross-reactivity with non-target microorganisms | No cross-reactivity observed with 35 microorganisms and human genomic DNA. |
| Interference | No interference | No interference observed with tested microorganisms and substances at specified concentrations. |
| Carry-over/Cross-contamination | 0% contamination rate | 0% carry-over/cross-contamination observed. |
| Fresh vs. Frozen Samples | 100% agreement | 100% agreement with expected results. |
| Clinical Performance (vs. Comparator Test) | ||
| Prospective Specimens | ||
| Inf A - Positive Agreement | High (e.g., ≥95%) | 98.3% (95.1% - 99.4%) |
| Inf A - Negative Agreement | High (e.g., ≥95%) | 96.0% (94.7% - 97.0%) |
| Inf B - Positive Agreement | High (e.g., ≥90%) | 95.2% (84.2% - 98.7%) |
| Inf B - Negative Agreement | High (e.g., ≥98%) | 99.4% (98.8% - 99.7%) |
| RSV - Positive Agreement | High (e.g., ≥95%) | 97.0% (91.5% - 99.0%) |
| RSV - Negative Agreement | High (e.g., ≥98%) | 98.7% (97.9% - 99.2%) |
| Retrospective Specimens | ||
| Inf A - Positive Agreement | High (e.g., ≥95%) | 98.7% (93.0% - 99.8%) |
| Inf A - Negative Agreement | High (e.g., ≥98%) | 99.1% (96.7% - 99.7%) |
| Inf B - Positive Agreement | High (e.g., ≥95%) | 99.0% (94.4% - 99.8%) |
| Inf B - Negative Agreement | High (e.g., ≥98%) | 99.5% (97.1% - 99.9%) |
| RSV - Positive Agreement | High (e.g., ≥95%) | 98.8% (93.6% - 99.8%) |
| RSV - Negative Agreement | High (e.g., ≥95%) | 96.6% (93.2% - 98.4%) |
2. Sample Size Used for the Test Set and Data Provenance
-
Clinical Test Set Sample Size:
- Prospective Specimens: 1,350 nasopharyngeal swab (NPS) specimens.
- Retrospective Specimens: 292 nasopharyngeal swab (NPS) specimens.
- Total Clinical Samples: 1,642 specimens.
-
Analytical Test Set Sample Size (Reproducibility): Approximately 900 runs (10 panel members × 3 replicates × 2 operators × 5 days × 3 sites).
-
Data Provenance:
- Country of Origin: United States (US). Prospective specimens were collected during the 2013-2014 and 2014-2015 flu seasons.
- Retrospective/Prospective: The study included both prospective and retrospective clinical specimens. Prospective specimens were collected from patients with signs and symptoms of respiratory infection and tested at 12 CLIA waived healthcare facilities. Retrospective specimens were obtained from two reference laboratories and distributed to 3 of the 12 CLIA waived sites for testing.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
The document states that the cobas Liat Influenza A/B & RSV assay results were compared against an "FDA-cleared laboratory-based multiplexed real-time reverse transcriptase PCR (RT-PCR) test (comparator test)."
- Number of Experts: Not explicitly stated as "experts" for ground truth adjudication in the traditional sense, as it relies on a comparator laboratory test. However, the interpretation of the comparator PCR results would implicitly rely on qualified laboratory personnel.
- Qualifications of Experts: Not detailed. It's inferred that the personnel performing and interpreting the comparator FDA-cleared RT-PCR tests were qualified laboratory technologists/scientists. For discordant results in prospective samples, PCR/sequencing was used as a tie-breaker. This would also imply qualified laboratory personnel.
4. Adjudication Method for the Test Set
- For the primary comparison, the cobas Liat assay results were compared directly against the FDA-cleared laboratory-based multiplexed real-time RT-PCR test (comparator test).
- For discordant results between the cobas Liat and the comparator test in the prospective specimens (specifically, when Liat was positive and comparator negative), PCR/sequencing was used as a "tie-breaker" or confirmatory method. For Influenza A, 41 such specimens were tested, with 18 confirmed positive and 23 negative by PCR/sequencing. For Inf B, 6 such specimens were tested, with 5 confirmed positive and 1 negative. For RSV, 15 such specimens were tested, with 3 confirmed positive and 12 negative.
- For retrospective specimens with discordant results (Liat positive, comparator negative), a similar PCR/sequencing method was used, though with fewer details on the number of confirmed cases (e.g., 1 Inf A sample was negative by PCR/sequencing, all 6 RSV samples were 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
This document describes the performance of an in vitro diagnostic (IVD) nucleic acid amplification test (NAAT), not an AI-assisted imaging device or a decision support system with human readers. Therefore, an MRMC comparative effectiveness study involving human readers and AI assistance is not applicable to this device.
6. If a Standalone (i.e., Algorithm Only Without Human-in-the-Loop Performance) Was Done
The cobas® Liat system is an automated diagnostic system (sample-to-answer) that performs nucleic acid purification, amplification, and detection, and provides an automated interpretation of the results. The results are reported as "Detected" or "Not Detected" for each virus by the instrument's software. As such, the performance data presented (e.g., clinical sensitivity and specificity) intrinsically represent the "standalone" performance of the algorithm/system, as human interpretation of complex signals (like in radiology) is minimized or absent in the final result determination. The operators (nurses and technologists) are responsible for sample collection, loading, and initiating the test, but the interpretation is automated.
7. The Type of Ground Truth Used
The primary ground truth for the clinical validation was an FDA-cleared laboratory-based multiplexed real-time RT-PCR test (comparator test). For discordant results, PCR/sequencing was used as a confirmatory method to establish a more definitive ground truth.
8. The Sample Size for the Training Set
The document does not specify a separate "training set" in the context of machine learning or AI models. This device is a molecular diagnostic assay (RT-PCR) with predefined chemical reactions and detection logic. Its "development" would involve optimizing reagents, primer/probe design, and reaction conditions, rather than training an algorithm on a distinct dataset. The performance characteristics described are from validation studies, not from a "training" phase.
9. How the Ground Truth for the Training Set Was Established
Given that this is an RT-PCR assay and not an AI/ML device that requires a "training set" with ground truth in the AI context, this question is not applicable. The "ground truth" for developing such an assay would come from extensive analytical characterization against known viral positive and negative samples, including quantified viral loads, verified by traditional virological methods (e.g., cell culture infectivity assays, reference PCR methods).
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July 25, 2016
Public Health Service
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
IQuum, Inc. David W. Gates, Ph.D. Senior Director, Regulatory Affairs 4300 Hacienda Drive Pleasanton, CA 94588
Re: K153544
Trade/Device Name: cobas® Influenza A/B & RSV Nucleic Acid Test for Use on the cobas® Liat System (cobas Liat Influenza A/B & RSV); cobas® Influenza A/B & RSV Quality Control Kit Regulation Number: 21 CFR 866.3980 Regulation Name: Respiratory Viral Panel Multiplex Nucleic Acid Assay Regulatory Class: II Product Code: OCC, OZE, OOI, JJX Dated: May 31, 2016 Received: June 1, 2016
Dear Dr. Gates:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food. Drug. and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the
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electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
If you desire specific advice for your device on our labeling regulations (21 CFR Parts 801 and 809), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638 2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
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You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely yours,
Steven R. Gitterman -S
for Uwe Scherf, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K153544
Device Name
- cobas® Influenza A/B & RSV Nucleic Acid Test for Use on the cobas® Liat System (cobas® Liat Influenza A/B & RSV); 2) cobas® Influenza A/B & RSV Quality Control Kit
Indications for Use (Describe)
-
- The cobas® Influenza A/B & RSV Nucleic Acid Test for Use on the cobas® Liat System (cobas® Liat Influenza A/B & RSV) is an automated multiplex real-time RT-PCR assay for the rapid in vitro qualitative detection and discrimination of influenza A virus, influenza B virus and respiratory syncytial virus (RSV) RNA in nasopharyngeal swab specimens from patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors. The test is intended for use as an aid in the diagnosis and differentiation of influenza B, and RSV in humans and is not intended to detect influenza C.
Negative results do not preclude influenza virus or RSV infection and should not be used as the sole basis for treatment or other patient management decisions. Conversely, positive results do not ruleout bacterial infection or co-infection with other viruses. The agent detected may not be the definite cause of disease.
- The cobas® Influenza A/B & RSV Nucleic Acid Test for Use on the cobas® Liat System (cobas® Liat Influenza A/B & RSV) is an automated multiplex real-time RT-PCR assay for the rapid in vitro qualitative detection and discrimination of influenza A virus, influenza B virus and respiratory syncytial virus (RSV) RNA in nasopharyngeal swab specimens from patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors. The test is intended for use as an aid in the diagnosis and differentiation of influenza B, and RSV in humans and is not intended to detect influenza C.
Performance characteristics for influenza A were established during the 2013-2014 and the 2014-2015 influenza seasons when influenza A/H3 and A/H1N1 pandemic were the predominant influenza A viruses in circulation. When other influenza A viruses are emerging, performance characteristics may vary.
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 department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
-
- The cobas® Influenza A/B & RSV Quality Control Kit contains External Controls for use with the cobas® Liat Influenza A/B & RSV assay. External Controls are run during the Add cobas® Liat Influenza A/B & RSV Tube Lot procedure. Additional External Controls should be tested in accordance with local, state, federal and/or accrediting organization requirements as applicable.
| Type of Use (Select one or both, as applicable) | |
|---|---|
| ☑ Prescription Use (Part 21 CFR 801 Subpart D) | ☐ Over-The-Counter Use (21 CFR 801 Subpart C) |
CONTINUE ON A SEPARATE PAGE IF NEEDED.
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510(K) SUMMARY
Summary Date: June 16, 2016
A. 510(k) Number: K153544
B. Purpose for Submission:
The purpose of this submission is to request 510k clearance of the cobas® Influenza A/B & RSV Nucleic Acid Test for Use on the cobas® Liat System (cobas® Liat Influenza A/B & RSV) and the cobas® Influenza A/B & RSV Quality Control Kit.
C. Measurand:
The cobas® Influenza A/B & RSV Nucleic Acid Test for Use on the cobas® Liat System is a rapid, automated in vitro diagnostic test for the qualitative detection of Influenza B and RSV RNA from nasopharyngeal swab (NPS) specimens from patients with signs and symptoms of respiratory infection.
D. Type of Test:
Multiplex nucleic acid assay for the qualitative detection of Influenza A, Influenza B and RSV RNA from NPS specimens, including nucleic acid isolation and multiplex real-time RT-PCR amplification using the cobas® Liat System.
E. Applicant:
IQuum, Inc. (a wholly-owned subsidiary of Roche Molecular Systems Inc.) 700 Nickerson Road Marlborough, MA 01752 Tel: 508-229-3200 Fax: 508-970-0119
Contact name: Lingjun Chen Title: Vice President, Point-of-care Operational Development Tel: 508-229-3203 Email: lingjun.chen@roche.com
F. Proprietary and Established Names:
-
- cobas Influenza A/B & RSV Nucleic Acid Test for Use on the cobas Liat System (cobas Liat Influenza A/B & RSV)
-
- cobas® Influenza A/B & RSV Quality Control Kit
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G. Regulatory Information:
-
- Regulation section:
- 21 CFR 866.3980. Respiratory Viral Panel Multiplex Nucleic Acid Assay
- Classification:
Class II
- Product code:
OCC, OZE, OOI, JJX
- Panel:
Microbiology (83)
H. Intended Use:
-
- Intended use(s):
-
- The cobas® Influenza A/B & RSV Nucleic Acid Test for Use on the cobas® Liat System (cobas Liat Influenza A/B & RSV) is an automated multiplex real-time RT-PCR assay for the rapid in vitro qualitative detection and discrimination of influenza A virus, influenza B virus and respiratory syncytial virus (RSV) RNA in nasopharyngeal swab specimens from patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors. The test is intended for use as an aid in the diagnosis and differentiation of influenza A, influenza B, and RSV in humans and is not intended to detect influenza C.
Negative results do not preclude influenza virus or RSV infection and should not be used as the sole basis for treatment or other patient management decisions. Conversely, positive results do not rule-out bacterial infection with other viruses. The agent detected may not be the definite cause of disease.
Performance characteristics for influenza A were established during the 2013-2014 and the 2014-2015 influenza seasons when influenza A/H3 and A/H1N1 pandemic were the predominant influenza A viruses in circulation. When other influenza A viruses are emerging, performance characteristics may vary.
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 department for testing. Viral culture should not be attempted in these cases unless a BSL3+ facility is available to receive and culture specimens.
-
- The cobas® Influenza A/B & RSV Quality Control Kit contains External Controls for use with the cobas ° Liat Influenza A/B & RSV assay. External Controls are run during the
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Add cobas "Liat Influenza A/B & RSV Tube Lot procedure. Additional External Controls should be tested in accordance with local, state, federal and/or accrediting organization requirements as applicable.
-
- Indication(s) for use:
Same as Intended Use
- Indication(s) for use:
-
- Special conditions for use statement(s):
For prescription use only
- Special conditions for use statement(s):
-
- Special instrument requirements:
Requires the cobas® Liat System
- Special instrument requirements:
I. Device Description:
The cobas Liat Influenza A/B & RSV Nucleic Acid Test for Use on the cobas Liat System ("cobas" Liat Influenza A/B & RSV assay") is a rapid, automated in vitro diagnostic test for the qualitative detection of influenza A, influenza B, and RSV RNA in nasopharyngeal swab (NPS) specimens eluted in viral transport media.
The assay targets a well-conserved region of the matrix gene of influenza A (Inf A target), the non-structural protein gene of influenza B (Inf B target), and the matrix gene of RSV (RSV target). An Internal Process Control (IPC) is also included. The IPC is present to control for adequate processing of the target viruses and to monitor the presence of inhibitors in the sample preparation and RT-PCR.
The assay utilizes a single-use disposable cobas® Liat Tube that holds the sample purification and PCR reagents, and hosts the sample preparation and PCR processes. The cobas Liat Tube uses a flexible tube as a sample vessel. It contains all required unit dose reagents pre-packed in tube segments, separated by peelable seals, in the order of reagent use.
The cobas "Liat System automates and integrates sample purification, nucleic acid amplification, and detection of the target sequence in biological samples. The cobas Liat System performs all assay steps from clinical sample and reports assay result automatically. During the testing process. multiple sample processing actuators of the cobas " Liat System compress the cobas" Liat Tube to selectively release reagents from tube segments, move the sample from one segment to another, and control reaction volume, temperature, and time to conduct sample preparation, nucleic acid extraction, target enrichment, inhibitor removal, nucleic acid elution and real-time PCR. An embedded microprocessor controls and coordinates the actions of these sample processors to perform all required assay processes within the closed cobas Liat Tube.
Positive and negative controls are provided in the cobas® Influenza A/B & RSV Quality Control Kit. The positive control comprises inactivated Influenza B and RSV virus in a dried format. The negative control comprises Universal Transport Media (UTM).
To perform the cobas Liat Influenza A/B & RSV assay, an operator first collects a nasopharyngeal swab and places the swab into UTM. The operator transfers the sample into cobas " Liat Influenza A/B & RSV assay tube using a transfer pipette, and scans the tube barcode to identify the test and the sample barcode to code the sample ID with the assay run on the
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cobas® Liat System. The cobas® Liat Tube is then inserted into the cobas® Liat System. The system performs all the test steps and outputs interpreted results (e.g. Influenza A Detected, Influenza B Not Detected, RSV Not Detected) in ~20 minutes. A report of the interpreted results can be viewed on the cobas " Liat System's LCD screen, and printed directly through a USB or network connected printer. No reagent preparation or additional steps are required other than adding the sample to the cobas Liat Tube. Because all the reagents are contained within the cobas Liat Tube and no sample or reagent needs to be removed from the tube, crosscontamination between samples is minimized.
The results are interpreted by the cobas Liat System software from measured fluorescent signals and real time curve recognition algorithm. All possible final test results are described below.
| Result Report | Interpretation | |
|---|---|---|
| InfluenzaA | Influenza A NotDetected | Negative test for Influenza A(no Influenza A RNA detected) |
| Influenza A Detected | Positive test for Influenza A(Influenza A RNA present) | |
| Influenza AIndeterminate.Repeat Assay. | Presence or absence of Influenza A cannot bedetermined. Repeat assay with same sample or, ifpossible, new sample. | |
| Influenza B | Influenza B NotDetected | |
| Influenza B Detected | Positive test for Influenza B(Influenza B RNA present) | |
| Influenza BIndeterminate.Repeat Assay. | Presence or absence of Influenza B cannot bedetermined. Repeat assay with same sample or, ifpossible, new sample. | |
| RSV | RSV Not Detected | |
| RSV Detected | Positive test for RSV(RSV RNA present) | |
| RSV Indeterminate.Repeat Assay. | Presence or absence of RSV cannot be determined.Repeat assay with same sample or, if possible, newsample. | |
| Assay Invalid. Repeat Assay | ||
| [Error]. Assay Aborted |
Interpretation of Results
If the test result is "Indeterminate" or "Invalid", the assay should be repeated with the same patient specimen, or if possible, with a newly collected specimens that have repeat "Indeterminate" or "Invalid" results should be sent to a laboratory for confirmatory testing.
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If an assay is aborted due to run error, or if an assay is aborted by user, the test should be repeated with the same sample or, if possible, a new sample. Roche Service Representative should be contacted if repeat "Errors" are reported.
Dual infections of Influenza A and Influenza B are rare. If the test result is "Influenza A Detected" and "Influenza B Detected", the assay should be repeated with the same patient specimen, or if possible, with a newly collected specimens that have repeat "Influenza A Detected" and "Influenza B Detected" results should be sent to a laboratory for confirmatory testing.
J. Substantial Equivalence Information:
-
- Predicate device name(s):
Hologic Prodesse ProFlu+™
- Predicate device name(s):
Roche cobas Influenza A/B Nucleic Acid Test for Use on the cobas Liat System
- Predicate 510(k) number(s):
K073029, K081030, K092500, K110968, K132129
K11387
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3. Comparison with predicate:
| Device: | Predicate: | Predicate: | |
|---|---|---|---|
| Item Name | cobas® Liat Influenza A/B & RSV | cobas® Liat Influenza A/B | ProFlu+ |
| Intended Use | The cobas® Influenza A/B & RSVNucleic Acid Test for Use on thecobas® Liat System is an automatedmultiplex real-time RT-PCR assayfor the rapid in vitro qualitativedetection and discrimination ofinfluenza A virus, influenza B virus,and respiratory syncytial virus(RSV) RNA in nasopharyngeal swabspecimens from patients with signsand symptoms of respiratoryinfection in conjunction with clinicaland epidemiological risk factors.The test is intended for use as an aidin the diagnosis and differentiationof influenza A, influenza B, andRSV in humans and is not intendedto detect influenza C.Negative results do not precludeinfluenza virus or RSV infection andshould not be used as the sole basisfor treatment or other patientmanagement decisions. Conversely,positive results do not rule-outbacterial infection or co-infectionwith other viruses. The agentdetected may not be the definitecause of disease.Performance characteristics for | The cobas® Influenza A/B NucleicAcid Test for Use on the cobas® LiatSystem is an automated multiplexreal-time RT-PCR assay for therapid in vitro qualitative detectionand discrimination of influenza Avirus and influenza B virus RNA innasopharyngeal swab specimensfrom patients with signs andsymptoms of respiratory infection inconjunction with clinical andepidemiological risk factors. Thetest is intended for use as an aid inthe differential diagnosis ofinfluenza A and influenza B inhumans and is not intended to detectinfluenza C.Negative results do not precludeinfluenza virus infection and shouldnot be used as the sole basis fortreatment or other patientmanagement decisions. Conversely,positive results do not rule-outbacterial infection or co-infectionwith other viruses. The agentdetected may not be the definitecause of disease.Performance characteristics forinfluenza A were established when | The ProFlu+ Assay is a multiplexReal Time RT-PCR in vitrodiagnostic test for the rapid andqualitative detection anddiscrimination of Influenza A Virus,Influenza B Virus, and RespiratorySyncytial Virus (RSV) nucleic acidsisolated and purified fromnasopharyngeal (NP) swabspecimens obtained fromsymptomatic patients. This test isintended for use to aid in thedifferential diagnosis of Influenza AInfluenza B and RSV viral infectionsin humans and is not intended todetect Influenza C.Negative results do not precludeInfluenza or RSV virus infection andshould not be used as the sole basisfor treatment or other managementdecisions. Conversely, positiveresults do not rule-out bacterialinfection or co-infection with otherviruses. The agent detected may notbe the definite cause of disease. Theuse of additional laboratory testingand clinical presentation must beconsidered in order to obtain thefinal diagnosis of respiratory viral |
| Device: | Predicate: | Predicate: | |
| Item Name | cobas® Liat Influenza A/B & RSV | cobas® Liat Influenza A/B | ProFlu+ |
| influenza A were established duringthe 2013-2014 and the 2014-2015influenza seasons when influenzaA/H3 and A/H1N1 pandemic werethe predominant influenza A virusesin circulation. When other influenzaA viruses are emerging, performancecharacteristics may vary.If infection with a novel influenza Avirus is suspected based on currentclinical and epidemiologicalscreening criteria recommended bypublic health authorities, specimensshould be collected with appropriateinfection control precautions fornovel virulent influenza viruses andsent to state or local healthdepartment for testing. Viral cultureshould not be attempted in thesecases unless a BSL3+ facility isavailable to receive and culturespecimens. | influenza A/H1 and A/H3 were thepredominant influenza A viruses incirculation. When other influenza Aviruses are emerging, performancecharacteristics may vary.If infection with a novel influenza Avirus is suspected based on currentclinical and epidemiologicalscreening criteria recommended bypublic health authorities, specimensshould be collected with appropriateinfection control precautions fornovel virulent influenza viruses andsent to state or local healthdepartment for testing. Viral cultureshould not be attempted in thesecases unless a BSL3+ facility isavailable to receive and culturespecimens. | infection.Performance characteristics forInfluenza A Virus were establishedwhen Influenza A/H3 and A/H1were the predominant Influenza Aviruses in circulation (2006-2007respiratory season). Performancecharacteristics for Influenza A wereconfirmed when Influenza A/H1,Influenza A/H3, and InfluenzaA/2009 H1N1 were the predominantInfluenza A viruses in circulation(2008 and 2009). When otherInfluenza A viruses are emerging,performance characteristics mayvary.If infections with a novel InfluenzaA virus is suspected based on currentclinical and epidemiologicalscreening criteria recommended bypublic health authorities, specimensshould be collected with appropriateinfection control precautions fornovel virulent Influenza viruses andsent to state or local healthdepartment for testing. Viral cultureshould not be attempted in thesecases unless a BSL3+ facility isavailable to receive and culturespecimens. | |
| Item Name | Device:cobas® Liat Influenza A/B & RSV | Predicate:cobas® Liat Influenza A/B | Predicate:ProFlu+ |
| Regulation | 21 CFR 866.3980 | (same) | (same) |
| Product Code | OCC | (same) | (same) |
| Assay Target | Influenza AInfluenza BRSV | Influenza AInfluenza B | Influenza AInfluenza BRSV |
| Sample Type | Nasopharyngeal Swab | (same) | (same) |
| Internal Control | Yes for sample preparation and RT-PCR performance usingencapsulated RNA | (same) | Yes for RT-PCR performance onlyusing in vitro transcribed RNA.Extraction control is recommendedbut not provided. |
| Influenza A Viral Target | Well conserved region of the matrixgene | (same) | (same) |
| Influenza B Viral Target | Well conserved region of the non-structural protein (NSP) gene | (same) | (same) |
| RSV Viral Target | Well conserved region of the matrix(M) gene | N/A | Polymerase gene |
| Extraction Method | Integrated silica-magnetic bead-based nucleic acid extraction | (same) | Silica-magnetic bead-based nucleicacid extraction using Roche MagNAPure LC System, or bioMérieuxNucliSENS easyMag |
| Assay Method | RT-PCR for detecting the presence /absence of viral RNA in clinicalspecimens | (same) | (same) |
| Detection Technique | Multiplex assay using differentreporter dyes for each target | (same) | (same) |
| Device: | Predicate: | Predicate: | |
| Item Name | cobas® Liat Influenza A/B & RSV | cobas® Liat Influenza A/B | ProFlu+ |
| Assay Result | Qualitative | (same) | (same) |
| AssayInstrument | cobas® Liat System | (same) | Roche MagNA Pure LC System, orbioMérieux NucliSENS easyMagCepheid SmartCycler II Real TimeInstrumentLaboratory equipment, e.g. pipettors,centrifuge, vortex, cold block,biosafety cabinet |
| Self ContainedSystem Assay | Yes, integrated PC, software, andtouch-screen display | (same) | No, different instruments, andexternal PC computers required |
| All AssayReagentsContained inDisposable | Yes, no manual reagent additionrequired | (same) | No, multiple manual reagenthandling and preparation stepsrequired |
| Sample VolumeDetection | Yes, automatically checks that inputsample volume exceeds lower limit | (same) | No |
| AutomatedAssay | Yes, sample preparation,amplification, detection, and resultinterpretation | (same) | No, multiple manual steps required |
| ErrorDiagnosticSystem | Yes, monitors and records systemparameters for error recovery orassay abort if unrecoverable | (same) | No |
| PCR CurvePatternRecognition | Yes, ensures abnormal PCR curvesare called "Invalid" or"Indeterminate" | (same) | No |
| Item Name | Device:cobas® Liat Influenza A/B & RSV | Predicate:cobas® Liat Influenza A/B | Predicate:ProFlu+ |
| AutomatedResultInterpretation | Yes, results reported as "Detected"or "Not Detected" for each virus | (same) | No, manual result interpretation |
| User | Hospital nurse and CLIA moderatecomplexity laboratory technologist.Nurses and medical assistants atemergency rooms, urgent careclinics, and outpatient clinics,including physician's offices. | (same) | High complexity laboratorytechnologist |
| TestAvailability | Random access, on-demand test | (same) | Batch processing |
| Time-to-result | ~20 minutes | (same) | ≥4 hours |
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K. Standard/Guidance Document Referenced (if applicable):
Guidance for Industry and FDA Staff – Establishing the Performance Characteristics of In Vitro Diagnostic Devices for the Detection or Detection and Differentiation of Influenza Viruses. Document issued on July 15, 2011. Docket number FDA-2008-D-0095.
L. Test Principle:
The cobas Liat Influenza A/B & RSV assay uses established nucleic acid test chemistry and assay protocol for viral RNA detection. The sample preparation methodology is based on chaotropic agent-based lysis and magnetic particle based nucleic acid purification. First, the NPS sample is diluted and mixed with an internal process control (IPC) comprising an encapsulated RNA. Chaotropic and proteolytic reagent then disrupts the three dimensional structure in macromolecules such as proteins and nucleic acids in the sample, and denatures them. Second, nucleic acids are isolated from lysates through binding to the surface of silica magnetic beads in the presence of a chaotropic salt, which removes water from hydrated molecules in solution. Third, the beads are separated from the lysates using a magnetic field, and the lysate removed. Fourth, the beads with captured nucleic acids are washed to remove possible inhibitors in the sample. Finally, the captured nucleic acids are eluted under low-salt conditions into a small volume of elution buffer.
Target amplification and detection uses TaqMan-probe based real-time polymerase chain reaction (RT-PCR). The Inf A primer and probe set is designed to specifically detect the matrix RNA from Influenza A virus. The Inf B primer and probe set is designed to specifically detect the non-structural protein (NSP) RNA from Influenza B viruses. The RSV primer and probe set is designed to specifically detect the matrix RNA from RSV. An IPC primer and probe set is also included to amplify the target region of the encapsulated RNA internal control.
Eluted viral RNA is first transcribed into cDNA using reverse transcriptase. This cDNA then undergoes a polymerase chain reaction (PCR) where the reaction mixture is repeatedly heated to denature the nucleic acid, and cooled to allow annealing of primers and extension of annealed primers by DNA polymerase to logarithmically amplify the specific region of the cDNA. Duallabeled fluorogenic hydrolysis (TaqMan) probes anneal to the specific target sequences located between the binding regions of forward and reverse primers. During the extension phase of the PCR cycle, the 5' nuclease activity of the polymerase degrades the probes, causing the reporter dyes to separate from the quenchers, thus generating fluorescent signals. Fluorescence intensities are monitored at each PCR cycle. When the fluorescence intensities exceed pre-determined thresholds, cycle threshold (Ct) values are returned for the specific analyte corresponding to the fluorescence channel.
All these sample preparation and real-time PCR amplification processes are conducted in a closed cobas® Liat Tube in ~20 minutes.
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M. Performance Characteristics (if/when applicable):
1. Analytical performance:
a. Precision/Reproducibility:
Reproducibility study assesses the total variability of the cobas® Liat Influenza A/B & RSV assay across operators, study sites, testing days, cobas Liat Analyzers, and cobas "Liat Influenza A/B & RSV Assay Tube lots. The cobas " Liat Influenza A/B & RSV assay was evaluated at 3 sites. Two (2) operators at each of the 3 sites tested a 10 member reproducibility panel in triplicate on 5 different days, for a total of ~900 runs (10 panel members × 3 replicates × 2 operators × 5 days × 3 sites). Nine (9) cobas Liat Analyzer and 3 cobas Liat Influenza A/B & RSV Assay Tube lots were used. The reproducibility panel comprises a high negative (C;), a low positive (C15), and a medium positive (C100) for each of Influenza B and RSV, in addition to a negative sample. For a given virus, the expected result for the true negative and the high negative panel member is "Not Detected", while the expected result for the low positive and moderate positive panel member is "Detected". Percent agreement with expected result, mean Ct, and Ct %CV for each site are shown in the tables below.
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Influenza A Reproducibility
| Site 1 | Site 2 | Site 3 | Total | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample | Agreementw/ expectedresult | Ct Avg | Ct %CV | Agreementw/ expectedresult | Ct Avg | Ct %CV | Agreementw/ expectedresult | Ct Avg | Ct %CV | Agreement w/expected result | 95% CI |
| Negative | 30 / 30 | - | - | 31 / 31 | - | - | 30 / 30 | - | - | 91 / 91 (100.0%) | 96.0% - 100.0% |
| Flu A HighNegative (C5) | 29 / 30 | 37.0 | - | 30 / 30 | - | - | 29 / 30 | 35.7 | - | 88 / 90 (97.8%) | 92.3% - 99.4% |
| Flu A LowPositive (C95) | 30 / 30 | 32.7 | 2.9% | 30 / 30 | 32.1 | 1.6% | 30 / 30 | 32.3 | 1.6% | 90 / 90 (100.0%) | 95.9% - 100.0% |
| Flu A ModeratePositive (C100) | 30 / 30 | 30.4 | 1.0% | 30 / 30 | 30.0 | 1.2% | 30 / 30 | 30.1 | 0.9% | 90 / 90 (100.0%) | 95.9% - 100.0% |
| Flu B HighNegative (C5) | 30 / 30 | - | - | 31 / 31 | - | - | 30 / 30 | - | - | 91 / 91 (100.0%) | 96.0% - 100.0% |
| Flu B LowPositive (C95) | 30 / 30 | - | - | 30 / 30 | - | - | 29 / 29 | - | - | 89 / 89 (100.0%) | 95.9% - 100.0% |
| Flu B ModeratePositive (C100) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% |
| RSV HighNegative (C5) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% |
| RSV LowPositive (C95) | 30 / 30 | - | - | 31 / 31 | - | - | 30 / 30 | - | - | 91 / 91 (100.0%) | 96.0% - 100.0% |
| RSV ModeratePositive (C100) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% |
| Total Agreement | 299 / 300 (99.7%) | - | 303 / 303 (100.0%) | 298 / 299 (99.7%) | 900 / 902 (99.8%) | 99.2% - 99.9% |
- 1 of 30 Flu B Low Positive (C95) replicates yielded an "Assay Invalid. Repeat Assay." result, and was not repeated.
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Influenza B Reproducibility
| Site 1 | Site 2 | Site 3 | Total | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample | Agreementw/ expectedresult | Ct Avg | Ct %CV | Agreementw/ expectedresult | Ct Avg | Ct %CV | Agreementw/ expectedresult | Ct Avg | Ct %CV | Agreement w/expected result | 95% CI | |
| Negative | 30 / 30 | - | - | 31 / 31 | - | - | 30 / 30 | - | - | 91 / 91 (100.0%) | 96.0% - 100.0% | |
| Flu A HighNegative (C5) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% | |
| Flu A LowPositive (C95) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% | |
| Flu A ModeratePositive (C100) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% | |
| Flu B HighNegative (C5) | 29 / 30 | 35.1 | - | 31 / 31 | - | - | 30 / 30 | - | - | 90 / 91 (98.9%) | 94.0% - 99.8% | |
| Flu B LowPositive (C95) | 30 / 30 | 31.9 | 1.8% | 30 / 30 | 31.6 | 1.4% | 29 / 29† | 31.6 | 1.5% | 89 / 89 (100.0%) | 95.9% - 100.0% | |
| Flu B ModeratePositive (C100) | 30 / 30 | 30.8 | 1.3% | 30 / 30 | 30.4 | 1.4% | 30 / 30 | 30.5 | 1.3% | 90 / 90 (100.0%) | 95.9% - 100.0% | |
| RSV HighNegative (C5) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% | |
| RSV LowPositive (C95) | 30 / 30 | - | - | 31 / 31 | - | - | 30 / 30 | - | - | 91 / 91 (100.0%) | 96.0% - 100.0% | |
| RSV ModeratePositive (C100) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% | |
| Total Agreement | 299 / 300 (99.7%) | 303 / 303 (100.0%) | 299 / 299 (100.0%) | 901 / 902 (99.9%) | 99.4% - 100.0% |
- 1 of 30 Flu B Low Positive (C95) replicates yielded an "Assay Invalid. Repeat Assay." result, and was not repeated.
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RSV Reproducibility
| Site 1 | Site 2 | Site 3 | Total | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample | Agreementw/ expectedresult | Ct Avg | Ct %CV | Agreementw/ expectedresult | Ct Avg | Ct %CV | Agreementw/ expectedresult | Ct Avg | Ct %CV | Agreement w/expected result | 95% CI |
| Negative | 30 / 30 | - | - | 31 / 31 | - | - | 30 / 30 | - | - | 91 / 91 (100.0%) | 96.0% - 100.0% |
| Flu A HighNegative (C5) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% |
| Flu A LowPositive (C95) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% |
| Flu A ModeratePositive (C100) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% |
| Flu B HighNegative (C5) | 30 / 30 | - | - | 31 / 31 | - | - | 30 / 30 | - | - | 91 / 91 (100.0%) | 96.0% - 100.0% |
| Flu B LowPositive (C95) | 30 / 30 | - | - | 30 / 30 | - | - | 29 / 29† | - | - | 89 / 89 (100.0%) | 95.9% - 100.0% |
| Flu B ModeratePositive (C100) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% |
| RSV HighNegative (C5) | 30 / 30 | - | - | 30 / 30 | - | - | 30 / 30 | - | - | 90 / 90 (100.0%) | 95.9% - 100.0% |
| RSV LowPositive (C95) | 29 / 30 | 33.0 | 3.7% | 31 / 31 | 32.8 | 3.4% | 30 / 30 | 32.8 | 2.7% | 90 / 91 (98.9%) | 94.0% - 99.8% |
| RSV ModeratePositive (C100) | 30 / 30 | 30.6 | 2.9% | 30 / 30 | 30.9 | 1.6% | 30 / 30 | 30.5 | 2.5% | 90 / 90 (100.0%) | 95.9% - 100.0% |
| Total Agreement | 299 / 300 (99.7%) | 303 / 303 (100.0%) | 299 / 299 (100.0%) | 901 / 902 (99.9%) | 99.4% - 100.0% |
- 1 of 30 Flu B Low Positive (C95) replicates yielded an "Assay Invalid. Repeat Assay." result, and was not repeated.
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b. Linearity/assay reportable range:
Not Applicable
c. Traceability, Stability, Expected values (controls, calibrators, or methods):
The cobas Liat Influenza A/B & RSV assay has 3 controls: (1) internal process control, (2) positive control and (3) negative control.
Internal Process Control
The internal process control (IPC) comprises an encapsulated RNA that is pre-packed in each cobas " Liat Tube. When conducting an assay, it is first mixed with sample and then goes through all the test processes to monitor both the sample preparation and RT-PCR performance. The IPC RNA is detected in a separate channel by IPC specific primers and probe. If IPC Ct does not meet the acceptance criteria and Inf A, Inf B, and RSV are not detected, the assay run is called "Invalid" to avoid false negative results due to excessive sample inhibition or system operation outside the normal range.
Positive Control
Positive control is provided in the cobas® Influenza A/B & RSV Assay Quality Control Kit. The positive control comprises a pooled sample of inactivated Influenza A, Influenza B and RSV in a dried format. The positive control is designed to be detected at near LOD Ct using the cobas Liat Influenza A/B & RSV assay.
To use the positive control, an operator transfers a unit dose of UTM from the Dilution UTM tube into the Positive Control tube using an included transfer pipette to dissolve and mix the dried positive control. The entire mixture is then transfer into the cobas Ciat Tube, and the cobas Liat Tube is run on a cobas Liat System according to the Instructions for Use.
The positive control is required to be run during the "Add Liat Tube Lot" process, in which the cobas Liat tube lot and end user site procedures are checked at the end user site. Additional positive control runs may be performed by the end-user to confirm the performance of a cobas Liat System and a cobas Liat Tube lot through detection of Influenza A, Influenza B and RSV targets, or as required by the end user's quality control standards.
Negative Control
Negative control is provided in the cobas Influenza A/B & RSV Assay Quality Control Kit. The negative control comprises UTM. The solution is provided in unit dose quantity and labeled as Dilution UTM.
To use the negative control, an operator transfers the entire contents of the Dilution UTM tube into the cobas Liat Tube using a transfer pipette and runs the assay following the Instructions for Use.
The negative control is required to be run during the "Add Liat Tube Lot" process, in which potential contamination and end user site procedures are checked at the end user site. Additional negative control runs may be performed by the end-user to check if there is contamination resulting in a false positive result, or as required by the end user's quality control standards.
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d. Detection limit:
The Limit of Detection (LOD) of the cobas ) Liat Influenza A/B & RSV assay was evaluated using 3 strains of Influenza A, 2 strains of Influenza B, and 2 strains of RSV. The LOD was determined by limiting dilution studies using these titered viruses were spiked into negative nasopharyngeal swab (NPS) in UTM sample matrix, and then tested using the cobas Liat Influenza A/B & RSV assay. The LOD was determined as the lowest virus concentration that was detected ≥95% of the time (i.e. concentration at which at least 19 out of 20 replicates tested positive). The LOD was 2×103 - 2×102 TCID50/mL for Influenza A strains, 2×103 - 4×103 TCID50/mL for Influenza B strains, and 4×10 + TCID50/mL for RSV strains.
| Virus Strain | LOD (TCID50/mL) |
|---|---|
| A/Brisbane/10/07 | 2.0 × 10-2 |
| A/Brisbane/59/07 | 2.0 × 10-3 |
| A/NY/01/2009 | 2.0 × 10-2 |
| B/Florida/04/06 | 2.0 × 10-3 |
| B/Malaysia/2506/04 | 4.0 × 10-3 |
| RSV A | 4.0 × 10-1 |
| RSV B | 4.0 × 10-1 |
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e. Analytical specificity (reactivity):
The reactivity study evaluates the ability to detect Influenza and RSV strains representing temporal and geographical diversity. The cobas Ciat Influenza A/B & RSV assay was evaluated with 28 Influenza A, 15 Influenza B, and 7 RSV strains. Influenza A strains included 14 Influenza A/H1 strains (including 3 H1N1 pdm09 strains), 12 Influenza A/H3 strains (including 1 H3N2v strain), 1 Influenza A/H7N9 strains, and 1 Influenza A/H5N1 reassortant strain. Influenza B strains included that from both the Victoria lineage and Yamagata lineage. RSV strains included both RSV Type A and Type B strains. The cobas® Liat Influenza A/B & RSV assay detected all strains at the concentrations tested.
| Virus Strain | Type / Subtype | Test Concentration | Inf AResult | Inf BResult | RSVResult |
|---|---|---|---|---|---|
| A/Aichi/2/68 | Influenza A/H3N2 | $1.0×10^2$ CEID50/mL | + | - | - |
| A/Alice | Influenza A/H3N2 | $5.0×10^1$ CEID50/mL | + | - | - |
| A/Anhui/1/2013 | Influenza A/H7N9 (Eurasianlineage) | $1.0×10^3$ TCID50/mL | + | - | - |
| A/Brisbane/10/07 | Influenza A/H3N2 | $2.0×10^{-2}$ TCID50/mL | + | - | - |
| A/Brisbane/59/07 | Influenza A/H1N1 | $2.0×10^{-3}$ TCID50/mL | + | - | - |
| A/Cambodia/X0810301/2013(H5N1)-PR8-IDCDC-RG34B | Influenza A/H5N1 reassortant | $2.5×10^1$ CEID50/mL | + | - | - |
| A/Denver/1/57 | Influenza A/H1N1 | $1.0×10^2$ CEID50/mL | + | - | - |
| A/FM/1/47 | Influenza A/H1N1 | $1.0×10^2$ CEID50/mL | + | - | - |
| A/H3/Perth/16/09 | Influenza A/H3N2 | $2.5×10^{-1}$ TCID50/mL | + | - | - |
| A/Hong Kong/8/68 | Influenza A/H3N2 | $1.0×10^2$ TCID50/mL | + | - | - |
| A/Indiana/8/2011 | Influenza A/H3N2v | $5.0×10^1$ TCID50/mL | + | - | - |
| A/Mal/302/54 | Influenza A/H1N1 | $4.0×10^2$ CEID50/mL | + | - | - |
| A/MRC2 | Influenza A/H3 | $1.0×10^2$ CEID50/mL | + | - | - |
| A/New Caledonia/20/99 | Influenza A/H1N1 | $1.0×10^2$ TCID50/mL | + | - | - |
| A/New Jersey/8/76 | Influenza A/H1N1 | $1.0×10^1$ CEID50/mL | + | - | - |
| A/NY/01/2009 | Influenza A/H1N1 pdm09 | $2.0×10^{-2}$ TCID50/mL | + | - | - |
| A/NY/02/2009 | Influenza A/H1N1 pdm09 | $2.5×10^{-2}$ TCID50/mL | + | - | - |
| A/NY/03/2009 | Influenza A/H1N1 pdm09 | $2.0×10^1$ TCID50/mL | + | - | - |
| A/Port Chalmers/1/73 | Influenza A/H3N2 | $1.0×10^2$ CEID50/mL | + | - | - |
| A/PR/8/34 | Influenza A/H1N1 | $5.0×10^0$ TCID50/mL | + | - | - |
| A/Solomon Island/3/2006 | Influenza A/H1N1 | $5.0×10^{-2}$ TCID50/mL | + | - | - |
| A/Swine/1976/31 | Influenza A/H1N1 | $1.0×10^1$ CEID50/mL | + | - | - |
| Virus Strain | Type / Subtype | Test Concentration | Inf AResult | Inf BResult | RSVResult |
| A/Swine/Iowa/15/30 | Influenza A/H1N1 | $1.0\times10^{2}$ CEID50/mL | + | - | - |
| A/Texas/50/2012 | Influenza A/H3N2 | $1.0\times10^{1}$ TCID50/mL | + | - | - |
| A/Victoria/3/75 | Influenza A/H3N2 | $1.0\times10^{2}$ CEID50/mL | + | - | - |
| A/Victoria/361/2011 | Influenza A/H3N2 | $2.0\times10^{-2}$ TCID50/mL | + | - | - |
| A/Weiss/43 | Influenza A/H1N1 | $1.0\times10^{3}$ TCID50/mL | + | - | - |
| A/Wisconsin/67/05 | Influenza A/H3N2 | $5.0\times10^{1}$ TCID50/mL | + | - | - |
| B/Allen/45 | Influenza B | $5.0\times10^{1}$ TCID50/mL | - | + | - |
| B/Brisbane/60/2008 | Influenza B (Victoria lineage) | $1.0\times10^{-2}$ TCID50/mL | - | + | - |
| B/Florida/04/06 | Influenza B (Yamagatalineage) | $2.0\times10^{-3}$ TCID50/mL | - | + | - |
| B/Florida/07/04 | Influenza B (Yamagatalineage) | $5.0\times10^{-2}$ TCID50/mL | - | + | - |
| B/GL/1739/54 | Influenza B | $2.0\times10^{0}$ TCID50/mL | - | + | - |
| B/HongKong/5/72 | Influenza B | $2.5\times10^{1}$ TCID50/mL | - | + | - |
| B/Lee/40 | Influenza B | $2.5\times10^{1}$ TCID50/mL | - | + | - |
| B/Malaysia/2506/04 | Influenza B (Victoria lineage) | $4.0\times10^{-3}$ TCID50/mL | - | + | - |
| B/Maryland/1/59 | Influenza B | $5.0\times10^{-2}$ TCID50/mL | - | + | - |
| B/Mass/3/66 | Influenza B | $1.0\times10^{1}$ TCID50/mL | - | + | - |
| B/Massachusetts/2/2012 | Influenza B (Yamagatalineage) | $5.0\times10^{-3}$ TCID50/mL | - | + | - |
| B/Nevada/03/2011 | Influenza B (Victoria lineage) | $2.5\times10^{-1}$ CEID50/mL | - | + | - |
| B/Taiwan/2/62 | Influenza B | $1.0\times10^{0}$ TCID50/mL | - | + | - |
| B/Texas/6/2011 | Influenza B (Yamagatalineage) | $1.0\times10^{1}$ TCID50/mL | - | + | - |
| B/Wisconsin/1/2010 | Influenza B (Yamagatalineage) | $5.0\times10^{1}$ TCID50/mL | - | + | - |
| RSV A 2006 isolate | RSV A | $4.0\times10^{-1}$ TCID50/mL | - | - | + |
| RSV A Long | RSV A | $1.0\times10^{2}$ TCID50/mL | - | - | + |
| RSV A2 | RSV A | $1.0\times10^{0}$ TCID50/mL | - | - | + |
| RSV B 9320 | RSV B | $1.0\times10^{0}$ TCID50/mL | - | - | + |
| RSV B Ch93(18)-18 | RSV B | $4.0\times10^{1}$ TCID50/mL | - | - | + |
| RSV B Wash/18537 | RSV B | $1.0\times10^{0}$ TCID50/mL | - | - | + |
| RSV B WV/14617/85 | RSV B | $1.0\times10^{1}$ TCID50/mL | - | - | + |
{22}------------------------------------------------
{23}------------------------------------------------
f. Analytical specificity (Cross-reactivity):
Cross reactivity study evaluates potential cross-reactivity with non-influenza and non-RSV microorganisms that may be present in nasopharyngeal swab samples. The cobas Liat Influenza A/B & RSV assay was evaluated against a panel comprising human genomic DNA and 35 microorganisms. Bacteria and Candida albicans were tested at ≥10° CFU/mL. Viruses were tested at ≥10 TCID50/mL, or the highest available concentration. The cobas® Liat Influenza A/B & RSV assay showed no cross reactivity for the human genomic DNA or the microorganisms at the concentrations tested.
| Microorganism | Test Concentration | Inf A Result | Inf B Result | RSV Result |
|---|---|---|---|---|
| Adenovirus Type 1 | $9.0\times10^5$ TCID50/mL | - | - | - |
| Adenovirus Type 7 | $1.4\times10^5$ TCID50/mL | - | - | - |
| Cytomegalovirus | $4.5\times10^4$ TCID50/mL | - | - | - |
| Epstein Barr Virus | $2.5\times10^5$ TCID50/mL | - | - | - |
| Herpes Simplex Virus | $1.4\times10^5$ TCID50/mL | - | - | - |
| Human Coronavirus 229E | $8.0\times10^3$ TCID50/mL | - | - | - |
| Human Coronavirus OC43 | $8.0\times10^4$ TCID50/mL | - | - | - |
| Human Enterovirus 68 | $1.0\times10^5$ TCID50/mL | - | - | - |
| Human Metapneumovirus | $7.0\times10^3$ TCID50/mL | - | - | - |
| Human Parainfluenza Type 1 | $3.7\times10^5$ TCID50/mL | - | - | - |
| Human Parainfluenza Type 2 | $7.5\times10^5$ TCID50/mL | - | - | - |
| Human Parainfluenza Type 3 | $4.5\times10^5$ TCID50/mL | - | - | - |
| Human Rhinovirus Type 1A | $8.0\times10^5$ TCID50/mL | - | - | - |
| Measles | $8.0\times10^4$ TCID50/mL | - | - | - |
| Mumps Virus | $8.0\times10^4$ TCID50/mL | - | - | - |
| Varicella-Zoster Virus | $4.4\times10^3$ TCID50/mL | - | - | - |
| Bordetella pertussis | $2.2\times10^6$ CFU/mL | - | - | - |
| Candida albicans | $4.2\times10^6$ CFU/mL | - | - | - |
| Chlamydia pneumoniae | $8.0\times10^4$ TCID50/mL | - | - | - |
| Corynebacterium sp | $3.6\times10^6$ CFU/mL | - | - | - |
| Escherichia coli | $1.9\times10^6$ CFU/mL | - | - | - |
| Haemophilus influenzae | $2.3\times10^6$ CFU/mL | - | - | - |
| Lactobacillus sp | $1.9\times10^6$ CFU/mL | - | - | - |
| Legionella pneumophila | $6.7\times10^6$ CFU/mL | - | - | - |
| Moraxella catarrhalis | $2.5\times10^6$ CFU/mL | - | - | - |
| Mycobacterium tuberculosis | $2.8\times10^6$ copies/mL† | - | - | - |
| Microorganism | Test Concentration | Inf A Result | Inf B Result | RSV Result |
| Mycoplasma pneumoniae | $2.9\times10^6$ copies/mL† | – | – | – |
| Neisseria elongate | $2.0\times10^6$ CFU/mL | – | – | – |
| Neisseria meningitidis | $2.2\times10^6$ CFU/mL | – | – | – |
| Pseudomonas aeruginosa | $2.3\times10^6$ CFU/mL | – | – | – |
| Staphylococcus aureus | $2.4\times10^6$ CFU/mL | – | – | – |
| Staphylococcus epidermidis | $1.9\times10^6$ CFU/mL | – | – | – |
| Streptococcus pneumoniae | $1.8\times10^6$ CFU/mL | – | – | – |
| Streptococcus pyogenes | $2.5\times10^6$ CFU/mL | – | – | – |
| Streptococcus salivarius | $4.3\times10^6$ CFU/mL | – | – | – |
| Human genomic DNA | $1.0\times10^4$ copies/mL | – | – | – |
{24}------------------------------------------------
† Testing was performed with genomic DNA due to difficulties in propagation of these bacteria.
{25}------------------------------------------------
g. Interfering Microorganisms:
Interfering microorganism study evaluates whether non-influenza and non-RSV microorganisms that may be present in nasopharyngeal swab samples can interfere in the detection of Influenza A, Influenza B or RSV by the cobas Liat Influenza A/B & RSV assay. The panel comprising human genomic DNA and 35 microorganisms tested in the cross-reactivity study was tested for potential interference. Bacteria and Candida albicans were tested at ≥10° CFU/mL, and viruses were tested at ≥10 TCIDsp/mL or the highest available concentration, in the presence of 1 Influenza A strain, 1 Influenza B strain and 1 RSV strain at 3x LOD concentration in negative NPS in UTM matrix. Results show that the presence of human genomic DNA or the microorganisms at the concentrations tested did not interfere with the detection of Influenza A, Influenza B. or RSV.
| Microorganism | Test Concentration | 1 Flu A, 1 Flu B &1 RSV strain at 3x LOD | ||
|---|---|---|---|---|
| Inf A Result | Inf B Result | RSV Result | ||
| Adenovirus Type 1 | $9.0\times10^5$ TCID50/mL | + | + | + |
| Adenovirus Type 7 | $1.4\times10^5$ TCID50/mL | + | + | + |
| Cytomegalovirus | $4.5\times10^4$ TCID50/mL | + | + | + |
| Epstein Barr Virus | $2.5\times10^5$ TCID50/mL | + | + | + |
| Herpes Simplex Virus | $1.4\times10^5$ TCID50/mL | + | + | + |
| Human Coronavirus 229E | $8.0\times10^3$ TCID50/mL | + | + | + |
| Human Coronavirus OC43 | $8.0\times10^4$ TCID50/mL | + | + | + |
| Human Enterovirus 68 | $1.0\times10^5$ TCID50/mL | + | + | + |
| Human Metapneumovirus | $7.0\times10^3$ TCID50/mL | + | + | + |
| Human Parainfluenza Type 1 | $3.7\times10^5$ TCID50/mL | + | + | + |
| Human Parainfluenza Type 2 | $7.5\times10^5$ TCID50/mL | + | + | + |
| Human Parainfluenza Type 3 | $4.5\times10^5$ TCID50/mL | + | + | + |
| Human Rhinovirus Type 1A | $8.0\times10^5$ TCID50/mL | + | + | + |
| Measles | $8.0\times10^4$ TCID50/mL | + | + | + |
| Mumps Virus | $8.0\times10^4$ TCID50/mL | + | + | + |
| Varicella-Zoster Virus | $4.4\times10^3$ TCID50/mL | + | + | + |
| Bordetella pertussis | $2.2\times10^6$ CFU/mL | + | + | + |
| Candida albicans | $4.2\times10^6$ CFU/mL | + | + | + |
| Chlamydia pneumoniae | $8.0\times10^4$ TCID50/mL | + | + | + |
| Corynebacterium sp | $3.6\times10^6$ CFU/mL | + | + | + |
| Escherichia coli | $1.9\times10^6$ CFU/mL | + | + | + |
| Haemophilus influenzae | $2.3\times10^6$ CFU/mL | + | + | + |
| Lactobacillus sp | $1.9\times10^6$ CFU/mL | + | + | + |
| Legionella pneumophila | $6.7\times10^6$ CFU/mL | + | + | + |
| Moraxella catarrhalis | $2.5\times10^6$ CFU/mL | + | + | + |
| Mycobacterium tuberculosis | $2.8\times10^6$ copies/mL | + | + | + |
{26}------------------------------------------------
| Microorganism | Test Concentration | 1 Flu A, 1 Flu B &1 RSV strain at 3x LOD | ||
|---|---|---|---|---|
| Inf A Result | Inf B Result | RSV Result | ||
| Mycoplasma pneumoniae | $2.9 \times 10^6$ copies/mL† | + | + | + |
| Neisseria elongata | $2.0 \times 10^6$ CFU/mL | + | + | + |
| Neisseria meningitidis | $2.2 \times 10^6$ CFU/mL | + | + | + |
| Pseudomonas aeruginosa | $2.3 \times 10^6$ CFU/mL | + | + | + |
| Staphylococcus aureus | $2.4 \times 10^6$ CFU/mL | + | + | + |
| Staphylococcus epidermidis | $1.9 \times 10^6$ CFU/mL | + | + | + |
| Streptococcus pneumoniae | $1.8 \times 10^6$ CFU/mL | + | + | + |
| Streptococcus pyogenes | $2.5 \times 10^6$ CFU/mL | + | + | + |
| Streptococcus salivarius | $4.3 \times 10^6$ CFU/mL | + | + | + |
| Human Genomic DNA | $1.0 \times 10^4$ copies/mL | + | + | + |
† Testing was performed with genomic DNA due to difficulties in propagation of these bacteria.
{27}------------------------------------------------
h. Interfering substances
The cobas Liat Influenza A/B & RSV assay was evaluated with potentially interfering substances that may be encountered in respiratory specimens. Medically and/or physiologically relevant concentrations of potential interferents were tested with 2 Influenza A strains, 2 Influenza B strains, and 2 RSV strains at 3x LOD. Results showed that substances at the concentrations tested did not interfere in the detection of Influenza A, Influenza B, and RSV.
| Potential Interferent | Active Ingredient | Concentration |
|---|---|---|
| Mucin: bovine submaxillary gland,type I-S | Purified mucin protein | 5 mg/ml |
| Blood | 5% (v/v) | |
| Nasal spray - Afrin | Oxymetazoline | 5% (v/v) |
| Nasal corticosteroids - Veramyst | Fluticasone | 5% (v/v) |
| Nasal gel - Zicam | Galphimia glauca, Histaminumhydrochloricum, Luffa operculata, Sulphur | 5% (v/v) |
| Throat lozenges, oral anesthetic andanalgesic - Cepacol | Benzocaine, Menthol | 5 mg/ml |
| Antibiotic, nasal ointment – Bactroban | Mupirocin | 5 mg/ml |
| Antiviral drug – Relenza | Zanamivir | 5 mg/ml |
| Antiviral drug – Tamiflu | Oseltamivir | 7.5 mg/ml |
| Antimicrobial, systemic | Tobramycin | 4 µg/ml |
i. Carry-over/Cross-contamination:
A study was conducted to demonstrate that the single-use, self-contained cobas® Liat assay tube is not susceptible to carry-over contamination when alternating high positive and negative samples are tested. High positive samples comprised an influenza A virus spiked into negative nasopharyngeal swab in UTM matrix at a concentration greater than that expected in 95% or more of specimens of diseased patients in the intended use population. Negative samples comprised negative nasopharyngeal swab matrix. Twenty (20) high positive and 20 negative samples were tested on each of 2 cobas " Liat Systems (i.e. 40 high positive and 40 negative samples in total). High positive and negative samples were run alternating analyzer-to-analyzer and run-to-run. All 40 high positive samples tested were correctly reported as "Influenza A Detected". All 40 negative samples tested were correctly reported as "Influenza A Not Detected". There was no carry-over or cross contamination observed during this study.
{28}------------------------------------------------
Performance using Fresh vs. Frozen Samples: i.
The cobas® Liat Influenza A/B & RSV assay was tested by comparing its performance using fresh and frozen specimens. One (1) influenza A, 1 influenza B, and 1 RSV strain was individually spiked into nasopharyngeal swab in UTM matrix at different viral loads, including levels near the LOD and levels reflecting the clinical range. For each strain, at least 60 samples were tested immediately while at least another 60 samples were frozen at -80°C for 7 days, thawed and then tested. Ten (10) negative samples were also tested fresh and after being frozen at -80°C for 7 days. Fresh and frozen samples demonstrated 100% agreement with the expected result, demonstrating that the cobas Liat Influenza A/B & RSV assay had equivalent performance for fresh and frozen samples.
2. Comparison studies:
-
a. Method comparison with predicate device:
Not applicable -
b. Matrix comparison:
Not applicable
3. Clinical studies:
a. Clinical Sensitivity and Specificity:
The cobas Liat Influenza A/B & RSV assay was evaluated at 12 CLIA waived healthcare facilities. A total of 38 untrained operators representative of intended use operators at CLIA waived sites participated in the study. Prospective nasopharyngeal swab (NPS) specimens were collected from patients with signs and symptoms of respiratory infection in the US during the 2013-2014 and 2014-2015 flu seasons, and were tested prospectively at the study sites. Retrospective NPS specimens were obtained from two reference laboratories and were distributed to and tested at 3 of the 12 CLIA waived intended use sites. The retrospective specimens were worked into the daily workload of those sites for testing
Each patient's specimen was tested by the cobas Liat Influenza A/B & RSV and an FDAcleared laboratory-based multiplexed real-time reverse transcriptase PCR (RT-PCR) test (comparator test). The cobas Liat Influenza A/B & RSV assay results were compared against that from the comparator test. A total of 1.350 prospective NPS specimens and 292 retrospective NPS specimens were included in the performance analysis.
{29}------------------------------------------------
For prospective specimens, a total of 1.421 subjects were enrolled in this study. Of these, 41 specimens did not meet eligibility criteria. Additionally, 17 and 13 specimens were excluded due to invalid results from the cobas Liat and the comparator tests, respectively. As such, a total of 1,350 prospective NPS specimens were included in the performance analysis. Compared to the comparator test, the cobas Liat Influenza A/B & RSV assay demonstrated positive agreement of 98.3%, 95.2% and 97.0% for Inf A, Inf B and RSV, respectively; and negative agreement of 96.0%, 99.4% and 98.7% for Inf A, Inf B, and RSV, respectively.
Prospective NPS Specimens
| Inf A | Comparator Test | |||
|---|---|---|---|---|
| Positive | Negative | Total | ||
| Liat | Positive | 172 | 47a | 219 |
| Negative | 3 | 1128 | 1131 | |
| Total | 175 | 1175 | 1350 |
| % | 95% CI | |
|---|---|---|
| PositiveAgreement | 98.3% | (95.1% - 99.4%) |
| NegativeAgreement | 96.0% | (94.7% - 97.0%) |
a 41 Liat positive, comparator negative specimens were tested by PCR/sequencing. Of these, 18 were positive and 23 were negative by PCR/sequencing.
| Inf B | Comparator Test | |||
|---|---|---|---|---|
| Positive | Negative | Total | ||
| Liat | Positive | 40 | 8a | 48 |
| Negative | 2 | 1300 | 1302 | |
| Total | 42 | 1308 | 1350 |
| % | 95% CI | |
|---|---|---|
| PositiveAgreement | 95.2% | (84.2% - 98.7%) |
| NegativeAgreement | 99.4% | (98.8% - 99.7%) |
4 6 Liat positive, comparator negative specimens were tested by PCR/sequencing. Of these, 5 were positive and 1 was negative by PCR/sequencing.
| RSV | Comparator Test | |||
|---|---|---|---|---|
| Positive | Negative | Total | ||
| Liat | Positive | 96 | 16a | 112 |
| Negative | 3 | 1235 | 1238 | |
| Total | 99 | 1251 | 1350 |
| % | 95% CI | |
|---|---|---|
| PositiveAgreement | 97.0% | (91.5% - 99.0%) |
| NegativeAgreement | 98.7% | (97.9% - 99.2%) |
4 15 Liat positive, comparator negative specimens were tested by PCR/sequencing. Of these, 3 were positive and 12 were negative by PCR/sequencing.
{30}------------------------------------------------
For retrospective specimens, a total of 300 specimens were tested at clinical sites. Of these, 5 and 3 specimens were excluded due to invalid results from the cobas "Liat and the comparator tests, respectively. As such, a total of 292 retrospective NPS specimens were included in the performance analysis. Compared to the comparator test, the cobas Liat Influenza A/B & RSV assay demonstrated positive agreement of 98.7%, 99.0% and 98.8% for Inf A. Inf B and RSV, respectively; and negative agreement of 99.1%, 99.5% and 96.6% for Inf A, Inf B, and RSV, respectively.
Retrospective NPS Specimens
| Inf A | Comparator Test | % | 95% CI | ||||
|---|---|---|---|---|---|---|---|
| Positive | Negative | Total | PositiveAgreement | 98.7% | (93.0% - 99.8%) | ||
| Liat | Positive | 76 | 2a | 78 | NegativeAgreement | 99.1% | (96.7% - 99.7%) |
| Negative | 1 | 213 | 214 | ||||
| Total | 77 | 215 | 292 |
a 1 Liat positive, comparator negative specimen was tested by PCR/sequencing. This sample was negative by PCR/sequencing.
| Inf B | Comparator Test | |||
|---|---|---|---|---|
| Positive | Negative | Total | ||
| Liat | Positive | 97 | 1 | 98 |
| Liat | Negative | 1 | 193 | 194 |
| Total | 98 | 194 | 292 |
| % | 95% CI | |
|---|---|---|
| PositiveAgreement | 99.0% | (94.4% - 99.8%) |
| NegativeAgreement | 99.5% | (97.1% - 99.9%) |
| RSV | Comparator Test | ||||
|---|---|---|---|---|---|
| Positive | Negative | Total | |||
| Liat | Positive | 83 | 7a | 90 | |
| Negative | 1 | 201 | 202 | ||
| Total | 84 | 208 | 292 |
| % | 95% CI | |
|---|---|---|
| PositiveAgreement | 98.8% | (93.6% - 99.8%) |
| NegativeAgreement | 96.6% | (93.2% - 98.4%) |
4 6 Liat positive, comparator negative specimens were tested by PCR/sequencing. Of these, all 6 were positive by PCR/sequencing.
4. Clinical cut-off:
Not applicable
{31}------------------------------------------------
5. Expected values/Reference range:
In the cobas Liat Influenza A/B & RSV assay prospective clinical study, a total of 313 specimens were determined to be evaluable during the 2013-2014 influenza season from January 2014 to May 2014. The number and percentage of influenza B and RSV positive cases per specified age group, as determined by the cobas "Liat Influenza A/B & RSV assay, are presented in the tables below:
| Influenza A Positives by the cobas® Liat Influenza A/B & RSV Assay per Patient Age Group | |
|---|---|
| - 2013 to 2014 Influenza Season |
| Age Group | Number ofNasopharyngealSwab Specimens | Number of Influenza APositives | Influenza A Positivity Rate |
|---|---|---|---|
| ≤ 5 years | 135 | 5 | 3.7% |
| 6 to 21 years | 124 | 10 | 8.1% |
| 22 to 59 years | 45 | 3 | 6.7% |
| ≥ 60 years | 9 | 1 | 11.1% |
| Total | 313 | 19 | 6.1% |
Influenza B Positives by cobas Liat Influenza A/B & RSV Assay per Patient Age Group -2013 to 2014 Influenza Season
| Age Group | Number ofNasopharyngealSwab Specimens | Number of Influenza BPositives | Influenza B Positivity Rate |
|---|---|---|---|
| ≤ 5 years | 135 | 4 | 3.0% |
| 6 to 21 years | 124 | 11 | 8.9% |
| 22 to 59 years | 45 | 5 | 11.1% |
| ≥ 60 years | 9 | 0 | 0.0% |
| Total | 313 | 20 | 6.4% |
| Table 24: RSV Positives by cobas® Liat Influenza A/B & RSV Assay per Patient Age Group | ||
|---|---|---|
| - 2013 to 2014 Influenza Season |
| Age Group | Number ofNasopharyngealSwab Specimens | Number of Influenza BPositives | Influenza B Positivity Rate |
|---|---|---|---|
| ≤ 5 years | 135 | 8 | 5.9% |
| 6 to 21 years | 124 | 2 | 1.6% |
| 22 to 59 years | 45 | 3 | 6.7% |
| ≥ 60 years | 9 | 0 | 0.0% |
| Total | 313 | 13 | 4.2% |
{32}------------------------------------------------
A total of 1048 specimens were determined to be evaluable during the 2014-2015 influenza season from October 2014 to April 2015. The number and percentage of influenza A, influenza B and RSV positive cases per specified age group, as determined by the cobas® Liat Influenza A/B & RSV assay, are presented in the tables below:
Influenza A Positives by the cobas® Liat Influenza A/B & RSV Assay per Patient Age Group - 2014 to 2015 Influenza Season
| Age Group | Number ofNasopharyngealSwab Specimens | Number of Influenza APositives | Influenza A Positivity Rate |
|---|---|---|---|
| ≤ 5 years | 185 | 21 | 11.4% |
| 6 to 21 years | 284 | 78 | 27.5% |
| 22 to 59 years | 460 | 76 | 16.5% |
| ≥ 60 years | 119 | 29 | 24.4% |
| Total | 1048 | 204 | 19.5% |
Influenza B Positives by cobas® Liat Influenza A/B & RSV Assay per Patient Age Group -2014 to 2015 Influenza Season
| Age Group | Number ofNasopharyngealSwab Specimens | Number of Influenza BPositives | Influenza B Positivity Rate |
|---|---|---|---|
| ≤ 5 years | 185 | 1 | 0.5% |
| 6 to 21 years | 284 | 7 | 2.5% |
| 22 to 59 years | 460 | 18 | 3.9% |
| ≥ 60 years | 119 | 3 | 2.5% |
| Total | 1048 | 29 | 2.8% |
RSV Positives by cobas® Liat Influenza A/B & RSV Assay per Patient Age Group - 2014 to 2015 Influenza Season
| Age Group | Number ofNasopharyngealSwab Specimens | Number of Influenza BPositives | Influenza B Positivity Rate |
|---|---|---|---|
| ≤ 5 years | 185 | 54 | 29.2% |
| 6 to 21 years | 284 | 17 | 6.0% |
| 22 to 59 years | 460 | 23 | 5.0% |
| ≥ 60 years | 119 | 6 | 5.0% |
| Total | 1048 | 100 | 9.5% |
N. Instrument Name:
cobas® Liat System
{33}------------------------------------------------
O. System Descriptions:
1. Modes of Operation:
The cobas® Liat System functions as a point-of-care platform with sample-to-answer capabilities in which all sample processing steps as well as detection are carried out using a single-use, disposable cobas® Liat Tube.
2. Software:
Applicant's Hazard Analysis and software development processes for this line of product types has been provided:
Yes_X__or No ___________________________________________________________________________________________________________________________________________________________________________
3. Specimen Identification:
A sample barcode is scanned or a sample ID entered into the cobas Liat System during the assay run process. After scanning the sample barcode, the corresponding sample is loaded directly into a cobas® Liat Tube using a transfer pipette. After the tube is capped, the tube barcodes is scanned by the cobas Liat System and the tube is inserted into the system to start the test.
4. Specimen Sampling and Handling:
Specimen sampling and handling during the assay is controlled automatically using multiple sample processing modules contained within the cobas Liat System. The sample processing modules are composed of two assemblies, a moving side assembly comprised of multiple sample processing plungers and clamps and a fixed side assembly. When performing an assay, a cobas Liat Tube is inserted into the tube slot of a cobas Liat System. The plungers and clamps selectively compress the cobas® Liat Tube segments against the fixed side assembly to release reagents from the segments, move the sample from one segment to another, and control reaction conditions.
5. Calibration:
Not required. The cobas " Liat Tube is single use and part of a closed system.
6. Quality Control:
An internal process control used in conjunction with procedural checks monitors instrument functionality, performance, fluidics, and result determination based on a pre-defined decision algorithm.
P. Conclusion:
The submitted information in this premarket notification is complete and demonstrates that the cobas® Liat Influenza A/B & RSV assay is substantially equivalent to the predicate devices.
§ 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.