(177 days)
The Nano-Check Influenza A+B Test is a lateral flow immuno-chromatographic assay intended for the qualitative detection of influenza A and influenza B nucleoprotein antigens directly from anterior nasal swab (ANS) samples from patients with signs and symptoms of respiratory infection. The test is intended for use as an aid in the differential diagnosis of influenza A and influenza B viral infections. The test is not intended for the detection of influenza C antigens. Negative test results are presumptive and should be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions.
Performance characteristics for influenza A and B were established during the 2022-2025 influenza seasons when influenza A/H1N1pdm09, influenza A/H3N2, and influenza B/Victoria lineage were the predominant influenza viruses in circulation. When other influenza viruses are emerging, performance characteristics may vary.
If infection with a novel influenza 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 the state or local health department for testing. Virus culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
The Nano-Check™ Influenza A+B Test is a lateral flow immunochromatographic assay intended for in vitro rapid, simultaneous qualitative detection and differentiation of influenza A, and influenza B nucleoprotein antigens directly from anterior nasal swab specimens.
The assay kit consists of 25 test cassette devices, 25 reagent tubes, 25 ampules containing extraction buffer, 25 anterior nasal specimen collection swabs, one positive control swab, one negative control swab, one Instructions for Use, and one Quick Reference Instruction. An external positive control swab contains noninfectious influenza A and influenza B antigens dried onto the swab and an external negative control swab contains noninfectious blank universal viral transport media dried on the swab. The kit should be stored at 2°C - 30°C.
N/A
FDA 510(k) Clearance Letter - Nano-Check Influenza A+B Test
Page 1
January 15, 2026
Nano-Ditech Corporation
James B Chang
President
259 Prospect Plains Rd., Bldg K
Cranbury, New Jersey 08512
Re: K252283
Trade/Device Name: Nano-Check Influenza A+B Test
Regulation Number: 21 CFR 866.3328
Regulation Name: Influenza Virus Antigen Detection Test System
Regulatory Class: Class II
Product Code: PSZ
Dated: July 21, 2025
Received: July 22, 2025
Dear James B Chang:
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 (the 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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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.
Page 2
K252283 - James B Chang Page 2
Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).
Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).
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 Part 801 and Part 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.
All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-
Page 3
K252283 - James B Chang Page 3
assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
JOSEPH BRIGGS -S
Joseph Briggs, Ph.D.
Deputy Division Director
Division of Microbiology Devices
OHT7: Office of In Vitro Diagnostics
Office of Product Evaluation and Quality
Center for Devices and Radiological Health
Enclosure
Page 4
DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
Indications for Use
Form Approved: OMB No. 0910-0120
Expiration Date: 07/31/2026
See PRA Statement below.
510(k) Number (if known)
K252283
Device Name
Nano-Check Influenza A+B Test
Indications for Use (Describe)
The Nano-Check Influenza A+B Test is a lateral flow immuno-chromatographic assay intended for the qualitative detection of influenza A and influenza B nucleoprotein antigens directly from anterior nasal swab (ANS) samples from patients with signs and symptoms of respiratory infection. The test is intended for use as an aid in the differential diagnosis of influenza A and influenza B viral infections. The test is not intended for the detection of influenza C antigens. Negative test results are presumptive and should be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions.
Performance characteristics for influenza A and B were established during the 2022-2025 influenza seasons when influenza A/H1N1pdm09, influenza A/H3N2, and influenza B/Victoria lineage were the predominant influenza viruses in circulation. When other influenza viruses are emerging, performance characteristics may vary.
If infection with a novel influenza 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 the state or local health department for testing. Virus culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
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.
This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.
The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:
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FORM FDA 3881 (8/23) Page 1 of 1 PSC Publishing Services (301) 443-6740 EF
Page 5
510(k) Summary
Nano-Check™ Influenza A+B Test
I. Submitter
Applicant: Nano-Ditech Corporation
259 Prospect Plains Rd., Bldg. K Cranbury, NJ 08512 USA
Phone:1-609-409-3300
Contact Person: James B Chang (jchang@nanoditech.com)
Date Prepared: December 16, 2025
II. Device
A. Trade, Proprietary, and Established Name: Nano-Check™ Influenza A+B Test
B. Product Code: PSZ
C. Classification: Class II
D. Regulation Number: 21 CFR 866.3328
E. Device Classification Name: Devices Detecting Influenza A, B, And C Virus Antigens
F. Panel: MI-Microbiology (83)
G. Submission Purpose: New device 510(k) clearance for Nano-Check™ Influenza A+B Test
H. Measurand: Influenza A Nucleoprotein Antigen, Influenza B Nucleoprotein Antigen
I. Type of Test: Qualitative lateral flow immunoassay
III. Predicate Device
A. Trade Name: BD Veritor™ System for Rapid Detection of Flu A+B CLIA Waived Kit
B. FDA 510k Number: K232434 (Cleared December 05, 2023)
C. Product Code: PSZ
IV. Indications for Use
A. Intended Use(s):
See Indications for Use below.
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B. Indication(s) for Use:
The Nano-Check™ Influenza A+B Test is a lateral flow immuno-chromatographic assay intended for the qualitative detection of influenza A and influenza B nucleoprotein antigens directly from anterior nasal swab (ANS) samples from patients with signs and symptoms of respiratory infection. The test is intended for use as an aid in the differential diagnosis of influenza A and influenza B viral infections. The test is not intended for the detection of influenza C antigens. Negative test results are presumptive and should be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions.
Performance characteristics for influenza A and B were established during the 2022-2025 influenza seasons when influenza A/H1N1pdm09, influenza A/H3N2, and influenza B/Victoria lineage were the predominant influenza viruses in circulation. When other influenza viruses are emerging, performance characteristics may vary.
If infection with a novel influenza 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 the state or local health department for testing. Virus culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
C. Special Conditions for Use Statement(s):
Rx - For Prescription Use Only
For In Vitro Diagnostic Use
D. Special Instrument Requirements:
N/A
V. Device/System Characteristics:
A. Device Description:
The Nano-Check™ Influenza A+B Test is a lateral flow immunochromatographic assay intended for in vitro rapid, simultaneous qualitative detection and differentiation of influenza A, and influenza B nucleoprotein antigens directly from anterior nasal swab specimens.
The assay kit consists of 25 test cassette devices, 25 reagent tubes, 25 ampules containing extraction buffer, 25 anterior nasal specimen collection swabs, one positive control swab, one negative control swab, one Instructions for Use, and one Quick Reference Instruction. An external positive control swab contains noninfectious influenza A and influenza B antigens dried onto the swab and an external negative control swab contains noninfectious blank universal viral transport media dried on the swab. The kit should be stored at 2°C - 30°C.
B. Principles of Operations:
The Nano-Check™ Influenza A+B Test is designed to detect the extracted nucleoprotein antigen specific to influenza A and influenza B in ANS specimens directly collected from patients exhibiting signs or symptoms of a respiratory infection.
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The test strip enclosed in a cassette housing is comprised of the following components: sample pad, reagent pad, biotin-free pad, reaction membrane, and absorbent pad. The reagent pad contains colloidal gold conjugated with monoclonal antibodies (mAb) specific to Flu A and Flu B target proteins. The reaction membrane contains the secondary antibodies for the proteins of Flu A and Flu B. The whole strip is fixed inside a plastic cassette.
When the specimens are extracted and added to the sample well of the test device, any Flu A and/or Flu B nucleoprotein antigens present in the specimen will form complexes with the anti-Flu A/Flu B conjugate which are then captured by the specific anti-Flu A/Flu B mAb coated on the test line region (A/B line). The absence of the test line (A/B line) suggests a negative result. To serve as a procedural control, a red line will always appear in the control line region (CON) indicating that proper volume of sample has been added and membrane wicking has occurred. Any result without this control line is invalid.
VI. Comparison of Technological Characteristics with the Predicate Device
The table below compares the Nano-Check™ Influenza A+B Test to the predicate devices of BD Veritor™ System for Rapid Detection of Flu A+B CLIA Waived Kit.
| Device & Predicate Device(s): | Predicate (K232434) | Candidate |
|---|---|---|
| Device Trade Name | BD Veritor™ System for Rapid Detection of Flu A+B CLIA Waived Kit | Nano-Check™ Influenza A+B Test |
Similarities
| Intended Use | The BD Veritor System for Rapid Detection of Flu A+B CLIA-Waived Kit is a rapid chromatographic immunoassay for the direct and qualitative detection of influenza A and B viral nucleoprotein antigens from nasal and nasopharyngeal swabs of symptomatic patients. The BD Veritor System for Rapid Detection of Flu A+B CLIA-Waived Kit (also referred to as the BD Veritor System and BD Veritor System Flu A+B) is a differentiated test, such that influenza A viral antigens can be distinguished from influenza B viral antigens from a single processed sample using a single device. The test is to be used as an aid in the diagnosis of influenza A and B viral infections. A negative test is presumptive, and it is recommended that these results be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions. The test is not intended to detect influenza C antigens. Performance characteristics for influenza A and B were established during January | The Nano-Check™ Influenza A+B Test is a lateral flow immuno-chromatographic assay intended for the qualitative detection of influenza A and influenza B nucleoprotein antigens directly from anterior nasal swab (ANS) samples from patients with signs and symptoms of respiratory infection. The test is intended for use as an aid in the differential diagnosis of influenza A and influenza B viral infections. The test is not intended for the detection of influenza C antigens. Negative test results are presumptive and should be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions. Performance characteristics for influenza A and B were established during the 2022-2025 influenza seasons when influenza A/H1N1pdm09, influenza A/H3N2, and influenza B/Victoria lineage were the predominant influenza viruses in circulation. When other influenza viruses are emerging, performance characteristics may vary. If infection with a novel influenza virus is suspected based on current clinical and |
Page 8
| through March of 2011 when influenza viruses A/2009 H1N1, A/H3N2, B/Victoria lineage, and B/Yamagata lineage were the predominant influenza viruses in circulation according to the Morbidity and Mortality Weekly Report from the CDC entitled "Update: Influenza Activity—United States, 2010–2011 Season, and Composition of the 2011–2012 Influenza Vaccine." Performance characteristics may vary against other emerging influenza viruses. If infection with a novel influenza 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 the state or local health department for testing. Virus culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens. | 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 the state or local health department for testing. Virus culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens. | |
|---|---|---|
| Regulation number | 21 CFR 866.3328 | Same |
| Analyte | Influenza A and B viral nucleoprotein antigens | Same |
| Assay Principle (Technology) | Immunochromatographic | Same |
| Test Result | Qualitative | Same |
Differences
| Predicate (K232434) | Candidate | |
|---|---|---|
| Reading Time | 10-15 minutes | 15 -20 minutes |
| Specimen Type | Nasal and nasopharyngeal swabs | Anterior nasal swab |
| Interpretation Result | An opto-electronic reader determines the line intensity | Visual determination |
VII. Performance Data
A. Analytical Performance
1. Precision/Reproducibility:
a) Precision and Repeatability
a) Within Laboratory Precision
The precision study 1 was undertaken by two operators with each operator conducting 24 test runs over a 12-day period, resulting in a total of 96 replicates per level. The study employed blind sample panels comprising true negative (TN), low positive (LP, 1× LoD), and moderate positive (MP, 3× LoD) samples for each analyte (influenza A and influenza B). The precision testing was conducted according to the Package Insert and the qualitative results are summarized in Table 1 below.
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Table 1. Precision Study 1 -Summary Result
| Sample | Test Line | No. of Positives / No. of Samples Tested (%) | Total No. of Positives / Total No. of Samples (%) |
|---|---|---|---|
| Operator 1 | Operator 2 | ||
| True Negative (TN) | Flu A | 0/48 (0%) | 0/48 (0%) |
| Flu B | 0/48 (0%) | 0/48 (0%) | |
| Flu A LP (1X LoD) | Flu A | 48/48 (100%) | 48/48 (100%) |
| Flu B | 0/48 (0%) | 0/48 (0%) | |
| Flu A MP (3X LoD) | Flu A | 48/48 (100%) | 48/48 (100%) |
| Flu B | 0/48 (0%) | 0/48 (0%) | |
| Flu B LP (1X LoD) | Flu A | 0/48 (0%) | 0/48 (0%) |
| Flu B | 48/48 (100%) | 48/48 (100%) | |
| Flu B MP (3X LoD) | Flu A | 0/48 (0%) | 0/48 (0%) |
| Flu B | 48/48 (100%) | 48/48 (100%) |
The study results demonstrated 100% agreement for all samples. These findings satisfied the acceptance criteria of the precision study.
Study 2 was specifically conducted to assess between-lot variability. The study used negative samples (TN, without virus analytes), high negative samples (HN, 0.1× LoD), low positive samples at C90, and moderate positive (MP, 3× LoD) samples for each analyte (influenza A and influenza B). Samples were blinded and tested randomized. This supplemental precision testing was conducted by three operators, with each operator conducting 12 test runs per lot over 12 days with three lots, resulting in a total of 144 replicates per level. The lot and operator stratified results from this testing are included in Table 2 below.
Table 2. Precision Study 2 -Summary Result
| Sample | Test Line | No. of Positives / No. of Samples Tested (%) | Total No. of Positives / Total No. of Samples (%) |
|---|---|---|---|
| Lot 1 | Lot 2 | ||
| True Negative | Flu A | 0/48 (0%) | 0/48 (0%) |
| Flu B | 0/48 (0%) | 0/48 (0%) | |
| Flu A (0.1X LoD) | Flu A | 0/48 (0%) | 0/48 (0%) |
| Flu B | 0/48 (0%) | 0/48 (0%) |
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| Sample | Test Line | No. of Positives / No. of Samples Tested (%) | Total No. of Positives / Total No. of Samples (%) |
|---|---|---|---|
| Lot 1 | Lot 2 | ||
| Flu A (C90) | Flu A | 42/48 (87.5%) | 41/48 (85.4%) |
| Flu B | 0/48 (0%) | 0/48 (0%) | |
| Flu A (3X LoD) | Flu A | 48/48 (100%) | 48/48 (100%) |
| Flu B | 0/48 (0%) | 0/48 (0%) | |
| Flu B (0.1X LoD) | Flu A | 0/48 (0%) | 0/48 (0%) |
| Flu B | 0/48 (0%) | 0/48 (0%) | |
| Flu B (C90) | Flu A | 0/48 (0%) | 0/48 (0%) |
| Flu B | 44/48 (91.7%) | 43/48 (89.6%) | |
| Flu B (3X LoD) | Flu A | 0/48 (0%) | 0/48 (0%) |
| Flu B | 48/48 (100%) | 48/48 (100%) |
The study results demonstrated that the performance was consistent across all three lots tested. Taken together, the results of both precision assessments demonstrate a test precision and a lot-to-lot precision that are consistent with the expectations for the analyte concentrations in the samples, the test's technology, and the test's LoD. The between-lot variability does not impact low-concentrated samples equal to or above 3 X LoD of the test.
b) Reproducibility
The reproducibility study was designed to evaluate site-to-site, operator-to-operator, and level-to-level variability and demonstrate that the Nano-Check™ Influenza A+B Test can be performed consistently and correctly. This study was conducted at 4 distinct sites, each with two (2) or three (3) different operators, testing three (3) reagent lots, using a coded panel of contrived samples consisting of a true negative (TN), a high negative sample (HN, 0.1x LoD), a low positive (LP, 1.0 x LoD) and a medium positive (MP, 5.0 x LoD) sample for each analyte (influenza A and influenza B). A total of 8 untrained operators at 3 CLIA waived sites and 3 operators in the internal site each tested using 105 coded samples (TN: 15, HN-Flu A: 15, HN-Flu B: 15, LP-Flu A: 15, LP-Flu B: 15, MP-Flu A: 15, MP-Flu B: 15, respectively) over five nonconsecutive days. The summary of results is presented in Table 3 below.
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Table 3. Reproducibility Study- Summary Result
| Sample | No. of Positives / No. of Samples Tested (%) | Total No. of Positives / Total No. of Samples (%) |
|---|---|---|
| CLIA-Waived Site 1 (2 operators) | CLIA-Waived Site 2 (3 operators) | |
| True Negative NCM | 0/30 (0%) | 0/45 (0%) |
| 0.1X LoD Flu A | 0/30 (0%) | 0/45 (0%) |
| 0.1X LoD Flu B | 0/30 (0%) | 0/45 (0%) |
| 1X LoD Flu A | 30/30 (100%) | 45/45 (100%) |
| 1X LoD Flu B | 30/30 (100%) | 45/45 (100%) |
| 5X LoD Flu A | 30/30 (100%) | 45/45 (100%) |
| 5X LoD Flu B | 30/30 (100%) | 45/45 (100%) |
All samples tested in the reproducibility study generated no significant difference between sites.
2. Linearity:
This section is not applicable as this test device is a qualitative assay.
3. Cross-reactivity (Analytical Specificity):
a) Cross-reactivity and Microbial Interference Study
Cross-Reactivity and Interference study of the Nano-Check™ Influenza A+B Test was conducted with 53 potential cross-reactive or interfering pathogens of bacteria (19), fungi (2), and viruses (30), and negative matrix (2). Each microorganism was tested in three (3) replicates in the absence or presence of 2x LoD concentrations of influenza A and influenza B antigens. The concentrations of potentially interfering microorganisms tested and the results from the cross-reactivity study are presented in Table 4 below.
Table 4. Results of Cross-Reactivity/Microbial Interference
| Microorganism (Strain) | Concentration Tested | Positive Sample (# Positive/# Tested)* | Negative Sample (# Positive/# Tested)* | Cross-Reactivity/Microbial Interference |
|---|---|---|---|---|
| Bordetella pertussis | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Candida albicans | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Chlamydophila pneumoniae | 1.0×10⁶ IFU/mL | 3/3 | 0/3 | No |
| Corynebacterium diphtheriae | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Escherichia coli | 1.0×10⁶ IFU/mL | 3/3 | 0/3 | No |
| Haemophilus influenzae, B | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Lactobacillus acidophilus | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
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| Microorganism (Strain) | Concentration Tested | Positive Sample (# Positive/# Tested)* | Negative Sample (# Positive/# Tested)* | Cross-Reactivity/Microbial Interference |
|---|---|---|---|---|
| Legionella Pneumophila subsp. Pneumophila | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Moraxella catarrhalis | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Mycobacterium tuberculosis | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Mycoplasma pneumoniae | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Neisseria meningitidis | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Neisseria mucosa | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Neisseria subflava | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Pseudomonas aeruginosa | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Pneumocystis jirovecii -S. cerevisiae | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Staphylococcus aureus | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Staphylococcus epidermidis | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Streptococcus pneumoniae | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Streptococcus pyogenes | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Streptococcus salivarius salivarius | 1.0×10⁶ cfu/mL | 3/3 | 0/3 | No |
| Epstein-Barr Virus | 1.0×10⁵ cp/mL | 3/3 | 0/3 | No |
| Enterovirus 71 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Enterovirus D 68 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Herpesvirus | 8.0×10⁴ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Adenovirus 1 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Adenovirus 2 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Adenovirus 7, Gomen | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Coronavirus, 229E | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Coronavirus, NL63 | 7.0×10⁴ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Coronavirus, OC43 | 4.5×10⁴ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Metapneumovirus 3, B1, Peru2-2002 | 1.95×10⁴ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Metapneumovirus, TN/83-1211 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Parainfluenza Virus 1 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Parainfluenza Virus 2 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Parainfluenza Virus 3 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Parainfluenza Virus 4B | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human RSV, A Long | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human RSV, A 9320 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human RSV, A2 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human RSV, B 18537 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human RSV, B WV/14617/85 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human RSV, B1 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Human Rhinovirus 1A, 2060 | 1.0×10⁵ PFU/mL | 3/3 | 0/3 | No |
| Measles Virus, Edmonston | 1.7×10⁴ TCID₅₀/mL | 3/3 | 0/3 | No |
| MERS-CoV, EMC/2012 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
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| Microorganism (Strain) | Concentration Tested | Positive Sample (# Positive/# Tested)* | Negative Sample (# Positive/# Tested)* | Cross-Reactivity/Microbial Interference |
|---|---|---|---|---|
| Mumps Virus, MuV/Iowa.US/2006 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Rhinovirus 20, 15-CV19 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| SARS-CoV | 1.0×10⁵ PFU/mL | 3/3 | 0/3 | No |
| SARS-CoV-2, USA/MD-HP20874/2021 | 1.95×10⁴ TCID₅₀/mL | 3/3 | 0/3 | No |
| SARS-CoV-2, USA/COR-22-063113/2022 | 1.0×10⁵ TCID₅₀/mL | 3/3 | 0/3 | No |
| Pooled Human Nasal Wash | N/A | 3/3 | 0/3 | No |
| Pooled Human Nasal Fluid | N/A | 3/3 | 0/3 | No |
Note: Coronavirus HKU1 was not tested for cross-reactivity due to a lack of availability. 20 clinical samples containing Coronavirus HKU1 were tested and all resulted as negative, however, the viral load/concentration of each sample is unknown.
*Results represent positive and negative results for both influenza A and B (i.e., 3 replicates for each).
The study results showed that none of the evaluated microorganisms demonstrated cross-reactivity or interference with the Nano-Check™ Influenza A+B Test at the tested concentrations.
b) Endogenous/Exogenous Interference
The Endogenous/Exogenous interference study of the Nano-Check™ Influenza A+B Test was conducted using medically relevant endogenous and exogenous interferents. The influenza A or influenza B were diluted in negative clinical matrix to 2x LoD separately and the potentially interfering substance was spiked to the concentration presented in Table 5 below. Three (3) replicates were tested for each sample prepared.
With the exception of the FluMist® trivalent live attenuated influenza vaccine, none of the substances caused a false positive result in the unspiked samples. While the presence of the FluMist® vaccine at 15% v/v concentration did not interfere with the detection of true positive results of the 3 x LoD co-spiked samples, the vaccine also resulted in false positive results for Flu A (as expected based on the composition of the vaccine) at 15% v/v. When diluted down to 1.5% v/v, the results of the unspiked samples were negative for Flu A. Hand sanitizer lotion at 15% v/v showed false negative results for Flu B, but detected all analytes at 10% v/v.
Table 5. Results of Endogenous/Exogenous Interference Study
| Substances | Interferent Conc. | Interference |
|---|---|---|
| Nasal Spray 1 | 15% v/v | No |
| Nasal Spray 2 | 15% v/v | No |
| Nasal Spray 3 | 15% v/v | No |
| Nasal Spray 4 | 15% v/v | No |
| Budesonide Nasal Spray | 15% v/v | No |
| Nasonex 24 hr Allergy | 15% v/v | No |
| Nasacort Allergy 24HR | 15% v/v | No |
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| Substances | Interferent Conc. | Interference |
|---|---|---|
| Sore Throat (Oral Pain Reliever spay) | 15% v/v | No |
| ZICAM® Oral mist | 15% v/v | No |
| Sore Throat Lozenges | 15% w/v | No |
| Zinc Cold Therapy | 15% w/v | No |
| Homeopathic Allergy Nasal Spray | 15% v/v | No |
| NasoGEL (Gel Spray) | 15% v/v | No |
| NasalCrom Nasal Allergy spray | 15% v/v | No |
| Histaminum 30C | 15% w/v | No |
| Skin relief hand cream | 1% w/v | No |
| Hand Soap Fresh Breeze Scent | 1% w/v | No |
| Antibacterial liquid Hand Soap | 15% w/v | No |
| Hand Sanitizer Gel | 15% w/v | No |
| Hand sanitizer lotion | 15% w/v | Yes |
| 10% w/v | No | |
| Disinfectant Spray | 1% v/v | No |
| Acetylsalicylic acid | 3.00×10¹ μg/mL | No |
| Dexamethasone | 1.20×10¹ μg/mL | No |
| Mometasone furoate | 4.50×10⁻⁴ μg/mL | No |
| Mupirocin | 1.50×10⁰ μg/mL | No |
| Oseltamivir phosphate | 3.99×10⁻¹ μg/mL | No |
| Tobramycin | 3.30×10¹ μg/mL | No |
| Beclomethasone dipropionate | 5.04 μg/mL | No |
| Flunisolide | 870 μg/mL | No |
| Molnupiravir | 3.29 mg/mL | No |
| Remdesivir | 240 μg/mL | No |
| Zanamivir | 30 mg/mL | No |
| Human Neutrophils | 5×10⁶ cells/mL | No |
| Mucin (Bovine submaxillary Glands, Type I-S) | 5 mg/mL | No |
| Whole Blood | 2.5% | No |
| FluMist® (Trivalent/Live) | 15% v/v* | Yes |
| 1.5% v/v | No | |
| Biotin | 3500 ng/mL | No |
*False positive results were also observed at 3% and 6% v/v.
4. Assay Reportable Range:
This section is not applicable as this test device is a qualitative assay.
5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):
a) Internal Quality Control
The Nano-Check™ Influenza A+B Test contains built in internal assay control. The appearance of the control line on the test ensures that sufficient flow of the sample occurred during the assay.
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b) External Quality Controls
The Nano-Check™ Influenza A+B Test contains one positive external control swab and one negative external control swab that allows for monitoring of the performance of the assay. The positive control swab contains recombinant influenza A nucleoprotein and recombinant influenza B nucleoprotein, and the negative control swab contains blank Universal Viral Transport media.
c) External Controls Lot-to-Lot Precision
The lot-to-lot precision for the external positive and negative control swabs was evaluated using three lots of external controls. The results from the study are summarized in Table 6 below.
Table 6. External Controls Lot-to-Lot Precision Study Results
| External control | Lot No. | No. of Positive Results / No. of Total Replicates (%) |
|---|---|---|
| Flu A | ||
| Positive External Control | 1 | 10/10 (100%) |
| 2 | 10/10 (100%) | |
| 3 | 10/10 (100%) | |
| Negative External Control | 1 | 0/10 (0%) |
| 2 | 0/10 (0%) | |
| 3 | 0/10 (0%) |
All lots of external controls generated 100% agreement with the expected results.
d) Specimen Stability
Two test samples were prepared for the specimen stability study: a negative sample (consisting of pooled human nasal fluid with no analyte) and a low positive sample (containing a diluted influenza A and influenza B sample at 2 x LoD in the negative pooled human nasal fluid). Swabs were spiked with 50 μL of each sample and subjected to four different temperature conditions: room temperature (23.5°C), high room temperature (30 °C), 2°C to 8°C and frozen (-20°C). The samples were stored under each condition for various time intervals including 0 hours, 1 hour, 2 hours, 4 hours, 8 hours, 24 hours, and 48 hours. Subsequently, the exposed sample swabs were tested using 5 replicates for each exposure time, as shown in Table 7 below.
Table 7. Specimen Stability Results
| Specimen Storage Temperature | Tested Sample | Specimen Storage Time (No. of Positive/No. of Total Test) |
|---|---|---|
| 0 hour | ||
| 23.5°C | Influenza A | 5/5 |
| Influenza B | 5/5 | |
| Negative | 0/5 | |
| 30°C | Influenza A | 5/5 |
| Influenza B | 5/5 | |
| Negative | 0/5 |
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| Specimen Storage Temperature | Tested Sample | Specimen Storage Time (No. of Positive/No. of Total Test) |
|---|---|---|
| 0 hour | ||
| 2°C to 8°C | Influenza A | 5/5 |
| Influenza B | 5/5 | |
| Negative | 0/5 | |
| -20°C | Influenza A | 5/5 |
| Influenza B | 5/5 | |
| Negative | 0/5 |
The results showed that the nasal swab samples were stable for up to 48 hours under all temperature conditions, ranging from -20°C to 30°C. The freshly collected specimens should be processed immediately after collection.
6. Detection Limit:
The Limit of Detection (LoD) was determined with two influenza A strains (influenza A H1N1: A/California/04 /2009, influenza A H3N2: A/Victoria/361/2011) and two influenza B strains (influenza B/Hong Kong/330/2001, influenza B/Phuket/3073/13). Contrived samples were prepared by spiking the strains into a pooled negative nasal fluid matrix. A preliminary LoD was determined by spiking 50 µL of serially diluted sample onto swab heads and tested using the Nano-Check™ Influenza A+B Test. The preliminary LoD initially determined by testing a two-fold serial dilution series of 3 replicates was confirmed by testing in 20 replicates. The results from these studies are summarized below in Table 8.
Table 8. Limit of Detection (LoD)
| Virus | Strain | LoD | Positive Rate (%) (# Positive/# Tested |
|---|---|---|---|
| Influenza A | H1N1: A/California/04/2009 | 2.8×10³ TCID₅₀/mL (1.4×10² TCID₅₀/swab) | 100% |
| H3N2: A/Victoria/361/2011 | 1.4×10⁵ CEID₅₀/mL (7.0×10³ CEID₅₀/swab) | 95% | |
| Influenza B | Victoria: B/Hong Kong/330/2001 | 2.25×10⁵ CEID₅₀/mL (1.13×10⁴ CEID₅₀/swab) | 95% |
| Yamagata: B/Phuket/3073/13 | 1.04×10² TCID₅₀/mL (5.2×10⁰ TCID₅₀/swab) | 100% |
7. Analytical Reactivity (Inclusivity):
A total of 27 strains of influenza A and 15 strains of influenza B were tested in the inclusivity study. The virus stocks were diluted at the predetermined concentration in the pooled negative nasal fluid matrix and 50 μL were pipetted onto the swabs. The swabs were tested in 3 replicates in this study. The lowest concentration of each strain that resulted in 100% detection (3/3) is presented in Table 9 below.
Page 17
Table 9. Inclusivity
| Virus | Virus Strains | Concentration Tested | Units |
|---|---|---|---|
| Flu A H1N1 | A/Puerto Rico/8/34 | 8.00E+06 | CEID₅₀/mL |
| A/Brisbane/59/2007 | 4.45E+06 | CEID₅₀/mL | |
| A/Denver/1/57 | 4.00E+05 | CEID₅₀/mL | |
| A/San Diego/1/2009 pdm09 | 2.80E+04 | TCID₅₀/mL | |
| A/Tijuana/4/09 | 2.45E+01 | TCID₅₀/mL | |
| A/Solomon Islands/3/2006 | 4.45E+05 | CEID₅₀/mL | |
| A/NWS/33 | 1.23E+05 | CEID₅₀/mL | |
| A/FM/1/47 | 4.25E+05 | CEID₅₀/mL | |
| A/New Jersey/8/76 | 1.70E+04 | CEID₅₀/mL | |
| A/New Caledonia/20/1999 | 4.00E+05 | CEID₅₀/mL | |
| A/Victoria/4897/2022(pdm09) | 1.58E+07 | EID₅₀/mL | |
| A/Victoria/2570/2019 (pdm09) | 9.98E+05 | EID₅₀/mL | |
| Flu A H1N2 | A/Swine/Ohio/09SW1477/2009 | 2.30E+04 | TCID₅₀/mL |
| Flu A H3N2 | A/Hong Kong/8/1968 | 1.40E+05 | CEID₅₀/mL |
| A/Aichi/2/1968 | 4.00E+05 | CEID₅₀/mL | |
| A/Wisconsin/67/2005 | 7.00E+05 | CEID₅₀/mL | |
| A/Hong Kong/4801/2014 | 9.60E+05 | CEID₅₀/mL | |
| A/Netherlands/22/2003 | 8.00E+02 | TCID₅₀/mL | |
| A/Netherlands/823/1992 | 1.44E+01 | TCID₅₀/mL | |
| A/Brisbane/10/2007 | 1.38E+05 | CEID₅₀/mL | |
| A/Wisconsin/15/2009 | 5.00E+03 | CEID₅₀/mL | |
| A/Sydney/5/97 | 4.45E+04 | CEID₅₀/mL | |
| A/Port Chalmers/1/73 | 2.00E+05 | CEID₅₀/mL | |
| A/Victoria/3/75 | 4.00E+05 | CEID₅₀/mL | |
| A/Perth/16/2009 x A/Puerto Rico/8/19 34, NIB-64 | 2.80E+06 | CEID₅₀/mL | |
| A/Singapore/INFIMH-16-0019 /16 | 2.51E+03 | TCID₅₀/mL | |
| Flu A H5N1 | A/mallard/Wisconsin/2576/2009 | 5.25E+05 | GE/mL |
| Flu B (Victoria Lineage) | B/Brisbane/60/2008 | 9.00E+04 | CEID₅₀/mL |
| B/Malaysia/2506/2004 | 1.12E+06 | CEID₅₀/mL | |
| B/New York/1056/2003 | 3.20E+03 | TCID₅₀/mL | |
| Flu B (Yamagata Lineage) | B/Florida/78/2015 | 2.80E+04 | TCID₅₀/mL |
| B/Texas/06/2011 | 4.45E+08 | CEID₅₀/mL | |
| B/New York/1061/2004 | 8.00E+02 | TCID₅₀/mL | |
| B/Christchurch/33/2004 | 8.00E+02 | TCID₅₀/mL | |
| B/Sydney/507/2006 | 1.60E+05 | TCID₅₀/mL | |
| B/Wisconsin/1/2010 | 1.80E+06 | CEID₅₀/mL | |
| B/Florida/4/2006 | 3.50E+05 | CEID₅₀/mL | |
| Flu B (Non-Victoria/Yamagata) | B/Colorado/6/17 | 1.78E+02 | TCID₅₀/mL |
| B/Taiwan/2/1962 | 4.45E+03 | CEID₅₀/mL | |
| B/Lee/1940 | 9.00E+04 | CEID₅₀/mL |
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| Virus | Virus Strains | Concentration Tested | Units |
|---|---|---|---|
| B/GL/1739/54 | 5.00E+04 | CEID₅₀/mL | |
| B/Great Lakes/1739/1954 | 3.20E+04 | CEID₅₀/mL |
8. High Dose Hook Effect:
High-dose hook effect study was conducted to determine if a hook effect would be observed at high concentrations of the analyte (i.e., a false negative at high concentrations of influenza A and influenza B) in a testing sample. The series of three or five concentrations with each two (2) strains of influenza A and influenza B were prepared in pooled negative nasal fluid matrix and tested in three replicates on Influenza A+B Test. The concentration of each virus in the prepared samples ranged from the maximum virus concentration possible (undiluted virus stock) to 2x LoD. All spiked samples were 100% positive, as expected, at all tested concentrations. The Nano-Check™ Influenza A+B Test showed no high-dose hook effect when subjected to 2.8×10⁶ TCID₅₀/mL for influenza A (A/California/04/2009, H1N1), 2.8×10⁸ CEID₅₀/mL for influenza A (A/Victoria/361/2011, H3N2), 1.8×10⁷ TCID₅₀/mL for influenza B (B/Hong Kong/330/2001, Victoria) and 4.17×10⁵ TCID₅₀/mL for influenza B (B/Phuket/3073/13, Yamagata).
9. Competitive Interference Study
For co-infection, influenza A at levels near LoD was tested in the presence of high levels of influenza B, and influenza B at levels near LoD was tested in the presence of high levels of influenza A. Contrived samples with both high and low titers of influenza A (H1N1 and H3N2) and influenza B were evaluated. No competitive interference was observed between influenza A and B as listed in Table 10 below.
Table 10. Competitive Inhibition
| High Titer Target | Low Titer Target | Low Titer Target Percent Positivity | ||
|---|---|---|---|---|
| Virus Name | Concentration Tested | Virus Name | Concentration Tested | |
| Flu A (H1N1) | 2.8 × 10⁵ | Flu B (Victoria) | 6.75 × 10⁵ | 100% |
| Flu A (H1N1) | 2.8 × 10⁵ | Flu B (Yamagata) | 3.12 × 10² | 100% |
| Flu A (H3N2) | 2.8 × 10⁶ | Flu B (Victoria) | 6.75 × 10⁵ | 100% |
| Flu A (H3N2) | 2.8 × 10⁶ | Flu B (Yamagata) | 3.12 × 10² | 100% |
| Flu B (Victoria) | 1.8 × 10⁶ | Flu A (H1N1) | 8.4 × 10³ | 100% |
| Flu B (Victoria) | 1.8 × 10⁶ | Flu A (H3N2) | 4.2 × 10⁵ | 100% |
| Flu B (Yamagata) | 4.17 × 10⁵ | Flu A (H1N1) | 8.4 × 10³ | 100% |
| Flu B (Yamagata) | 4.17 × 10⁵ | Flu A (H3N2) | 4.2 × 10⁵ | 100% |
9. Assay Cut-off:
Not Applicable
Page 19
10. Carry-Over:
Carry-over contamination is not applicable to this test device as each sample uses an independent, new, single-use test cassette that is discarded after each run.
B. Comparison Studies:
1. Method Comparison with Predicate Device:
Not applicable. The performance of the Nano-Check™ Influenza A+B Test was evaluated in a clinical study against an FDA-cleared molecular assay.
2. Matrix Comparison:
The Nano-Check™ Influenza A+B Test is only intended for the qualitative detection of influenza A and influenza B nucleoprotein antigens in direct anterior nasal swab specimens. As no other specimen or sample type is claimed herein.
C. Clinical Study:
The clinical performance of the Nano-Check™ Influenza A+B Test was evaluated in a multi-center, prospective clinical study in the U.S. between November 2022 and February 2025. The study only enrolled subjects who presented with symptoms of respiratory infection. A total of one thousand nine hundred sixty-nine (1,969) subjects were consecutively enrolled and tested by fourteen (14) operators across six (6) different clinical CLIA-waived sites. Two anterior nasal swabs were collected from each study subject during the same visit. The first AN swab specimen for the comparator method was collected by the operators from both sides of the nose. The collected AN swab specimen was stored/transported and tested at a reference laboratory with an FDA cleared RT-PCR method as per the cleared instruction for use. The second AN swab specimen was collected from both sides of the nose using the provided swab and was tested immediately using the Nano-Check™ Influenza A+B Test by an operator at the site.
There were 1,969 subjects evaluated, 21.1% were collected from patients who are 5 years or younger, 43.8% from patients aged 6-21 years, 26.3 % from patients aged 22 to 60 years, and 8.8% from patients aged 61 years or older. Among the subjects, 51.6% were from female patients, while 48.4% were from male patients. Results obtained with the Nano-Check™ Influenza A+B Test were compared to the results obtained with the RT-PCR comparator test to determine clinical sensitivity and specificity.
For influenza A detection, 480 of these specimens tested positive, and 1,489 tested negative by the FDA-cleared RT-PCR method. The comparison of Nano-Check™ Influenza A+B Test results with the comparator method results showed a PPA of 86.9% (417/480) with a 95% CI of 83.6% - 89.6%, NPA of 99.6% (1,483/1,489) with a 95% CI of 99.1% - 99.8%.
Page 20
For influenza B detection, 114 of these specimens tested positive, and 1,855 tested negative by the FDA-cleared RT-PCR method. The comparison of Nano-Check™ Influenza A+B Test results with the comparator method results showed a PPA of 86.8% (99/114) with a 95% CI of 79.4% - 91.9%, NPA of 99.7% (1,850/1,855) with a 95% CI of 99.4% - 99.9%.
Table 11. Clinical Performance of Nano-Check™ Influenza A+B Test Compared to an RT-PCR Comparator
Influenza A Detection
| Nano-Check™ Influenza A+B Test | RT-PCR Comparator | Total |
|---|---|---|
| Positive | Negative | |
| Positive | 417 | 6 |
| Negative | 63 | 1,483 |
| Total | 480 | 1,489 |
Positive Percent Agreement (PPA) = (417/480) x 100% = 86.9% (95% CI: 83.6% - 89.6%)
Negative Percent Agreement (NPA) = (1,483/1,489) x 100% = 99.6% (95% CI: 99.1% - 99.8%)
Influenza B Detection
| Nano-Check™ Influenza A+B Test | RT-PCR Comparator | Total |
|---|---|---|
| Positive | Negative | |
| Positive | 99 | 5 |
| Negative | 15 | 1,850 |
| Total | 114 | 1,855 |
Positive Percent Agreement (PPA) = (99/114) x 100% = 86.8% (95% CI: 79.4% - 91.9%)
Negative Percent Agreement (NPA) = (1,850/1,855) x 100% = 99.7% (95% CI: 99.4% - 99.9%)
1. Clinical Sensitivity:
Please refer to Section VI.C (Clinical Studies) above for the clinical validation. The PPAs for each analyte in the Nano-Check™ Influenza A+B Test are presented below.
a) Influenza A: 86.9% (417/480, 95% CI: 83.6% - 89.6%)
b) Influenza B: 86.8% (99/114, 95% CI: 79.4% - 91.9%)
2. Clinical Specificity:
Please refer to Section VI.C (Clinical Studies) above for the clinical validation. The NPAs for each analyte in the Nano-Check™ Influenza A+B Test are presented below.
a) Influenza A: 99.6% (1,483/1,489, 95% CI: 99.1% - 99.8%)
b) Influenza B: 99.7% (1,850/1,855, 95% CI: 99.4% - 99.9%)
D. Clinical Cut-Off:
Not Applicable since there is no clinical cutoff related to the presence of influenza A and influenza B in patient samples.
Page 21
E. Expected Value/Reference Range:
A patient sample is expected to be negative for influenza A and influenza B.
F. Other Supportive Information:
1. Flex Studies
To assess the robustness and risk for false results of the test when deviating from the IFU/QRI test steps, flex studies were conducted that assessed all major aspects of the test procedure (sample volume, reading time, other deviations from the procedure [delay in mixing, delay in addition of sample to the well, incubation time] and variability of environmental test conditions that the test may be subjected to when in use (lighting, disturbance during use, temperature and humidity stress conditions). The test was performed with contrived positive nasal swabs generated by diluting influenza A and influenza B into a negative nasal fluid matrix at 2xLoD. The results demonstrated that the test system is robust and that false results can be expected to be reasonably mitigated through labeling.
G. Conclusion
The information presented in this Premarket Notification is complete and supports a substantial equivalence decision. Based on the comparison of technological characteristics and intended use, and as a result of the non-clinical and clinical performance testing completed on Nano-Check™ Influenza A+B Test, the proposed device does not raise new questions of safety and effectiveness and supports the conclusion that the proposed device is substantially equivalent to the predicate device. The results of non-clinical and clinical testing demonstrate that the device is as safe, as effective, and performs as well as the predicate device. Therefore, the Nano-Check™ Influenza A+B Test is substantially equivalent to the predicate device.
§ 866.3328 Influenza virus antigen detection test system.
(a)
Identification. An influenza virus antigen detection test system is a device intended for the qualitative detection of influenza viral antigens directly from clinical specimens in patients with signs and symptoms of respiratory infection. The test aids in the diagnosis of influenza infection and provides epidemiological information on influenza. Due to the propensity of the virus to mutate, new strains emerge over time which may potentially affect the performance of these devices. Because influenza is highly contagious and may lead to an acute respiratory tract infection causing severe illness and even death, the accuracy of these devices has serious public health implications.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The device's sensitivity and specificity performance characteristics or positive percent agreement and negative percent agreement, for each specimen type claimed in the intended use of the device, must meet one of the following two minimum clinical performance criteria:
(i) For devices evaluated as compared to an FDA-cleared nucleic acid based-test or other currently appropriate and FDA accepted comparator method other than correctly performed viral culture method:
(A) The positive percent agreement estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 80 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 70 percent.
(B) The negative percent agreement estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 95 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 90 percent.
(ii) For devices evaluated as compared to correctly performed viral culture method as the comparator method:
(A) The sensitivity estimate for the device when testing for influenza A must be at the point estimate of at least 90 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 80 percent. The sensitivity estimate for the device when testing for influenza B must be at the point estimate of at least 80 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 70 percent.
(B) The specificity estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 95 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 90 percent.
(2) When performing testing to demonstrate the device meets the requirements in paragraph (b)(1) of this section, a currently appropriate and FDA accepted comparator method must be used to establish assay performance in clinical studies.
(3) Annual analytical reactivity testing of the device must be performed with contemporary influenza strains. This annual analytical reactivity testing must meet the following criteria:
(i) The appropriate strains to be tested will be identified by FDA in consultation with the Centers for Disease Control and Prevention (CDC) and sourced from CDC or an FDA-designated source. If the annual strains are not available from CDC, FDA will identify an alternative source for obtaining the requisite strains.
(ii) The testing must be conducted according to a standardized protocol considered and determined by FDA to be acceptable and appropriate.
(iii) By July 31 of each calendar year, the results of the last 3 years of annual analytical reactivity testing must be included as part of the device's labeling. If a device has not been on the market long enough for 3 years of annual analytical reactivity testing to have been conducted since the device received marketing authorization from FDA, then the results of every annual analytical reactivity testing since the device received marketing authorization from FDA must be included. The results must be presented as part of the device's labeling in a tabular format, which includes the detailed information for each virus tested as described in the certificate of authentication, either by:
(A) Placing the results directly in the device's § 809.10(b) of this chapter compliant labeling that physically accompanies the device in a separate section of the labeling where the analytical reactivity testing data can be found; or
(B) In the device's label or in other labeling that physically accompanies the device, prominently providing a hyperlink to the manufacturer's public Web site where the analytical reactivity testing data can be found. The manufacturer's home page, as well as the primary part of the manufacturer's Web site that discusses the device, must provide a prominently placed hyperlink to the Web page containing this information and must allow unrestricted viewing access.
(4) If one of the actions listed at section 564(b)(1)(A)-(D) of the Federal Food, Drug, and Cosmetic Act occurs with respect to an influenza viral strain, or if the Secretary of Health and Human Services (HHS) determines, under section 319(a) of the Public Health Service Act, that a disease or disorder presents a public health emergency, or that a public health emergency otherwise exists, with respect to an influenza viral strain:
(i) Within 30 days from the date that FDA notifies manufacturers that characterized viral samples are available for test evaluation, the manufacturer must have testing performed on the device with those viral samples in accordance with a standardized protocol considered and determined by FDA to be acceptable and appropriate. The procedure and location of testing may depend on the nature of the emerging virus.
(ii) Within 60 days from the date that FDA notifies manufacturers that characterized viral samples are available for test evaluation and continuing until 3 years from that date, the results of the influenza emergency analytical reactivity testing, including the detailed information for the virus tested as described in the certificate of authentication, must be included as part of the device's labeling in a tabular format, either by:
(A) Placing the results directly in the device's § 809.10(b) of this chapter compliant labeling that physically accompanies the device in a separate section of the labeling where analytical reactivity testing data can be found, but separate from the annual analytical reactivity testing results; or
(B) In a section of the device's label or in other labeling that physically accompanies the device, prominently providing a hyperlink to the manufacturer's public Web site where the analytical reactivity testing data can be found. The manufacturer's home page, as well as the primary part of the manufacturer's Web site that discusses the device, must provide a prominently placed hyperlink to the Web page containing this information and must allow unrestricted viewing access.