K071657 · Meridian Bioscience, Inc. · PSZ · Nov 15, 2007 · Microbiology
Device Facts
Record ID
K071657
Device Name
TRU FLU
Applicant
Meridian Bioscience, Inc.
Product Code
PSZ · Microbiology
Decision Date
Nov 15, 2007
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 866.3328
Device Class
Class 2
Attributes
Pediatric
Indications for Use
TRU FLU is a rapid, qualitative, lateral-flow immunochromatographic assay for detecting both influenza A and influenza B viral nucleoprotein antigens in human nasal wash, nasopharyngeal aspirate and nasal and nasopharyngeal swab samples in symptomatic patients. This test is not intended for the detection of influenza C viruses. A negative test is presumptive and it is recommended these results be confirmed by cell culture. Negative results do not preclude influenza virus infection and should not be used as the sole basis for treatment or other clinical management decisions.
Device Story
TRU FLU is a single-use, lateral-flow immunochromatographic assay for qualitative detection of influenza A and B nucleoprotein antigens. Input: human nasal wash, nasopharyngeal aspirate, or nasal/nasopharyngeal swab samples. Operation: patient specimen is mixed with sample diluent and a lyophilized bead containing colloidal gold-linked monoclonal antibodies (detector antibodies) in a conjugate tube; the mixture is applied to a nitrocellulose test strip. If antigens are present, they bind to detector antibodies and are captured by immobilized antibodies on the strip, forming visible pink-red lines at specific test positions. An internal control line confirms adequate flow. Used in clinical settings by healthcare professionals. Output: visual qualitative result (presence/absence of pink-red lines). Results aid clinical management but require confirmation by cell culture for negative findings.
Clinical Evidence
Clinical study evaluated 697 fresh and 63 frozen samples across 9 sites. Compared to tissue culture (reference), TRU FLU demonstrated varying sensitivity and specificity by sample type and age group. Overall fresh sample sensitivity for Influenza A was 86.3-87.2% and specificity 89.3-92.7%; for Influenza B, sensitivity was 58.5-63.6% and specificity 99.4-99.6%. No significant performance differences noted by patient age or gender.
Technological Characteristics
Single-use lateral-flow immunoassay. Components: nitrocellulose test strip with immobilized monoclonal capture antibodies, conjugate tube with lyophilized colloidal gold-linked monoclonal detector antibodies, and buffered protein sample diluent. No instrumentation required. Storage: 2-25°C. Manual visual readout.
Indications for Use
Indicated for symptomatic patients of all ages requiring detection of influenza A and B viral nucleoprotein antigens in nasal wash, nasopharyngeal aspirate, or nasal/nasopharyngeal swab samples. Prescription use only. Not for influenza C detection.
Regulatory Classification
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.
Special Controls
*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.
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510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
DEVICE ONLY TEMPLATE
A. 510(k) Number:
k071657
B. Purpose for Submission:
New Device Clearance
C. Measurand:
Influenza A and B nucleoprotein antigens
D. Type of Test:
Qualitative, in vitro immunochromatographic assay
E. Applicant:
Meridian Bioscience, Inc
F. Proprietary and Established Names:
TRU FLU
G. Regulatory Information:
a) Regulation section:
21CFR 866.3330; Influenza Virus Serological Reagents
b) Classification:
Class I
Product Code:
GNX, Antigens, CF, including CF controls, Influenza A, B, and C.
c) Panel:
83 Microbiology
H. Intended Use:
a) Intended use(s):
TRU FLU is a rapid, qualitative, lateral-flow immunochromatographic assay for detecting both influenza A and influenza B viral nucleoprotein antigens in human nasal wash, nasopharyngeal aspirate and nasal and nasopharyngeal swab samples in symptomatic patients. This test is not intended for the detection of influenza C viruses. A negative test is presumptive and it is recommended these results be confirmed by cell culture. Negative results do not preclude influenza virus infection and should not be used as the sole basis for treatment or other clinical management decisions.
b) Indication(s) for use:
Same as intended use.
c) Special condition for use statement(s):
The device is for prescription use only
d) Special instrument Requirements:
NA
I. Device Description:
In vitro immunochromatographic immunoassay
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J. Predicate device name(s):
Viral cell culture, ImmunoCard STAT! Flu A&B PLUS
2. Predicate $510(\mathbf{k})$ number(s): K041626
Comparison with predicate:
Table 1: Summary of Device Similarities and Differences
| Characteristics | TRU FLU | ImmunoCard STAT! Flu A&B PLUS (prior format) |
| --- | --- | --- |
| Device Type | | |
| Technology | Single use, rapid, lateral flow immunoassay | Single use, rapid, lateral flow immunoassay |
| In vitro diagnostic device | Yes | Yes |
| Control | Purchased separately | Purchased separately |
| Calibrator | No | No |
| Intended Use | | |
| Detection of influenza A antigen | Yes | Yes |
| Detection of influenza B antigen | Yes | Yes |
| Screening test | No | No |
| Diagnostic test | Yes | Yes |
| Identification test | No | No |
| Monitoring therapy | No | No |
| Acceptable Samples | | |
| Swab -- Nasal | Yes | Yes |
| Swab -- Nasopharyngeal | Yes | Yes |
| Wash -- Nasal | Yes | Yes |
| Wash -- Nasopharyngeal | Yes | Yes |
| Aspirate -- Nasopharyngeal | Yes | Yes |
| Reagents/Components Provided | | |
| Nitrocellulose test strip | Yes (attached to plastic holder/tube closure) | Yes (enclosed in plastic frame) |
| Conjugate reagent | Yes (supplied as dried bead in Conjugate Tube) | Yes (supplied in conjugate pad attached to test strip) |
| Reading Guide | Yes (part of plastic holder/tube | Yes (part of plastic frame) |
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Table 1 Continued
| Characteristics | TRU FLU | ImmunoCard STAT! Flu A&B PLUS
(prior format) |
| --- | --- | --- |
| Sample Diluent/Negative Control (external) | Yes | Yes |
| Internal procedural control | Yes | Yes |
| External positive control | No (Purchased separately -- FLU/RSV Positive Control, Catalogue 751110 | No (Purchased separately -- FLU/RSV Positive Control, Catalogue 751110 |
| Source of influenza A antibodies | Monoclonal M2110169, IVF8 | Monoclonal M2110169, IVF8 |
| Source of influenza B antibodies | Monoclonal 2/3, M2110171 | Monoclonal 2/3, M2110171 |
K. Standard/Guidance Document Referenced (if applicable):
N/A
L. Test Principle:
TRU FLU is a single use immunochromatographic assay that consists of a Conjugate Tube, a Test Strip, and Sample Diluent. The Conjugate Tube contains a lyophilized bead of colloidal gold-linked monoclonal antibodies to influenza A and influenza B (detector antibodies). The Test Strip carries a nitrocellulose membrane with dried capture antibodies at separate lines for influenza A and influenza B. The Test Strip holder caps the Conjugate Tube during testing and subsequent disposal to reduce exposure to potential pathogens. The conjugate bead is first rehydrated in the Conjugate Tube with Sample Diluent, prior to the addition of patient specimen. The contents are mixed before the Test Strip is added. As the test is incubated at 20-25°C, influenza A or influenza B antigens, if present in the diluted sample, bind to the corresponding monoclonal antibody-colloidal gold conjugate as the sample moves up the Test Strip. The influenza A capture monoclonal antibody is bound to the Test Strip at the test-FLU A position of the device. When it binds the antigen-influenza A antibody-colloidal gold complex, it yields a visible pink-red line. Similarly, the influenza B capture monoclonal antibody bound to the assay membrane at the test-FLU B position will result in a pink-red line when it captures antigen-influenza B antibody-colloidal gold complexes. When no antigen is present, no complexes are formed and no pink-red line will appear at either the test FLU A or the test FLU B position of the Test Strip. An internal control line helps determine whether adequate flow has occurred through the Test Strip during a test run. A visible pink-red line at the Control position of the Test Strip should be present each time a specimen or control is tested. If no pink-red control line is seen, the test is considered invalid.
M. Performance Characteristics (if/when applicable):
Analytical performance:
Precision/Reproducibility:
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Assay precision, intra-assay variability and inter-assay variability were assessed with a reference panel prepared from pools of negative samples spiked with specific virus. The reproducibility panel consisted of high positive $(n = 2)$ , low negative $(n = 1)$ , and low positive $(n = 4)$ and high negative specimens $(n = 4)$ . The latter were prepared near the assay limit of sensitivity. Each reference specimen was coded to prevent its identification during testing. Each was evaluated twice per day for three consecutive days by three different laboratories. High negative samples (viral load just below LOD) produced weakly positive results in 8 out of 72 high negative replicate tests performed with the samples prepared near the cutoff (See EP12-A, User protocol for evaluation of qualitative performance; approved guideline; NCCLS/CLSI, Vol. 22, no.14, 2002.) Low positive samples (viral concentration near the LOD) produced 1 negative result in 72 replicate tests. The high positive and low negative samples produced correct results $100\%$ of the time.
# a. Linearity/assay reportable range: NA
# b. Traceability, Stability, Expected values (controls, calibrators, or method): NA
# c. Detection limit:
The analytical sensitivity was assessed using two-fold serial dilutions of selected influenza A and influenza B virus stocks. The organisms tested are listed in the Table below. The sensitivity was the highest dilution that produced a definitive positive reaction.
| Strain ID | Influenza Strain | Limit of Detection (LOD) in pfu/mL |
| --- | --- | --- |
| Influenza A/Puerto Rico/8/34 | A (H1N1) | 9.8 X 103 |
| Influenza A/Hong Kong/8/68 | A (H3N2) | 7.3 X 104 |
| Influenza B/Lee/40 | B | 1.7 X 104 |
# d. Analytical specificity:
The specificity of TRU FLU was tested utilizing the following bacterial, viral and yeast strains. Positive and negative respiratory specimens were spiked with $\geq 4 \times 10^{7} / \mathrm{mL}$ bacteria or yeast. Virus inoculations were performed at $\geq 6.7 \times 10^{4} \mathrm{TCID}_{50} / \mathrm{mL}$ . None of the microorganisms tested yielded a positive result with the influenza-negative samples or interfered with detection of the influenza A and/or B positive samples. Both the negative and positive respiratory samples were positive when spiked with influenza A strain VR-100 or influenza B strain VR-295.
Adenovirus Types 1, 5 and 7A, Coxsackie Type A9, Human Coronavirus Types 229E and OC43, Cytomegalovirus, Measles, Human metapneumovirus, Parainfluenza Types 1, 2 and 3, Rhinovirus Type 39, RSV (2 strains), Bacillus cereus, Bacillus subtilis, Bordetella parapertussis, Bordetella pertussis, Branhamella catarrhalis, Candida albicans, Candida glabrata, Citrobacter freundii, Enterobacter cloacae, Escherichia coli, Enterococcus faecalis, Haemophilus influenzae, Klebsiella oxytoca, Klebsiella
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pneumoniae, Listeria monocytogenes, Legionella pneumophila, Neisseria cinerea, Neisseria gonorrhoeae, Neisseria meningitidis, Nocardia asteroides, Proteus vulgaris, Pseudomonas aeruginosa, Serratia liquifaciens, Staphylococcus aureus, Staphylococcus aureus (Cowan I), Staphylococcus epidermidis, Streptococcus (not typed), Streptococcus Groups A, B, D, F, and G, Streptococcus pneumoniae, Yersinia enterocolitica. A clinical sample containing Epstein Barr virus at $3.48 \times 10^{9}$ genome equivalents/mL was nonreactive with TRU FLU.
g. Interfering Substances:
The following substances were found to have no effect on results when present in respiratory samples at the concentrations indicated: Acetylsalicylic Acid (20 mg/mL), Acetaminophen (10 mg/mL), Halls® Throat Drops (20 mg/mL), Ludens® Throat Drops (20 mg/mL), Ricola® Throat Drops (20 mg/mL), Diphenhydramine (5 mg/mL), Dextromethorphan (9% v/v), Phenylephrine hydrochloride (9% v/v), Oxymetazoline hydrochloride (9% v/v), Chlorpheniramine maleate (5 mg/mL), Ibuprofen (10 mg/mL), Clemastine fumarate (5 mg/mL), Naproxen sodium (10 mg/mL), Loratadine (5 mg/mL), Pseudoephedrine (20 mg/mL), Listerine® Mouthwash (9% v/v), Scope® Mouthwash (9% v/v), Cepacol® Mouthwash (9% v/v), Whole blood (0.5%), Guaifenesin (9% v/v), Albuterol (9% v/v).
a. Comparison studies:
a. Method comparison with predicate device: N/A
b. Matrix comparison: NA
b. Clinical studies:
Clinical sensitivity:
Nine independent laboratories and the manufacturer, (located in distinct geographic regions), evaluated TRU FLU in parallel with tissue culture. Six hundred and ninety seven fresh and 63 frozen samples, collected prospectively during the 2006-7 influenza season were tested. In the case of frozen samples tissue culture tests were performed while they were fresh and before they were frozen. Twenty seven percent (185/697) of the prospective samples were from patients 22 years of age or older, $64\%$ (447/697) from patients 12 years of age or less and $8\%$ (59/697) from patients 13 to 21 years of age. The age of six patients donating samples was not recorded. Of the 63 samples tested only in the frozen state, the majority (33/63 or $52\%$) were from patients aged 2 months to 2 years. The patient ages for the remaining retrospective samples were $14\%$ (9/63) for patients aged 1 month or less, $22\%$ (14/63) for patients aged 3-12 years, and $11\%$ (7/63) for patients aged 13-21 years. Fifty three percent of the prospective and $51\%$ retrospective samples were from males while $47\%$ prospective and $49\%$ retrospective samples were from females. The gender of five patients donating samples was not recorded. No differences in performance were observed based on patient gender or patient age. The results of trials based on sample type are given in Tables 2-4. Of the
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697 prospective samples tested, 11 were not classified with respect to sample type and 1 produced invalid culture results. These 12 samples were excluded from the calculations.
Table 2. Results with prospective wash/aspirate samples
| | TRU FLU Flu A | | | TRU FLU Flu B | | |
| --- | --- | --- | --- | --- | --- | --- |
| Tissue Culture | Positive | Negative | Total | Positive | Negative | Total |
| Positive | 34 | 5 | 39 | 21 | 12 | 33 |
| Negative | 35* | 291 | 326 | 2 | 330 | 332 |
| Total | 69 | 296 | 365 | 23 | 342 | 365 |
| | | | 95% CI | | | 95% CI |
| Sensitivity | 34/39 | 87.2% | 72.6-95.7% | 21/33 | 63.6% | 45.1-79.6% |
| Specificity | 291/326 | 89.3% | 85.9-92.6% | 330/332 | 99.4% | 97.8-99.9% |
*NOTE: 2 samples were TRU FLU A+B+, tissue culture negative samples; another 3 were TRU FLU A+B+ and positive for influenza B by tissue culture. TRU FLU A+B+ tests were not repeated during the clinical trials. TRU FLU A+B+ tests are considered suspect without repeat testing.
Table 3. Results with prospectively frozen wash/aspirate samples
| | TRU FLU Flu A | | | TRU FLU Flu B | | |
| --- | --- | --- | --- | --- | --- | --- |
| Tissue Culture | Positive | Negative | Total | Positive | Negative | Total |
| Positive | 17 | 3 | 20 | 1 | 1 | 2 |
| Negative | 3 | 40 | 43 | 0 | 61 | 61 |
| Total | 20 | 43 | 63 | 1 | 62 | 63 |
| | | | 95% CI | | | 95% CI |
| Sensitivity | 17/20 | 85.0% | 62.1-96.8% | 1/2 | 50.0% | 1.3-98.7% |
| Specificity | 40/43 | 93.0% | 80.9-98.5% | 61/61 | 100% | 94.1-100% |
Table 4. Results with prospective swab samples
| | TRU FLU Flu A | | | TRU FLU Flu B | | |
| --- | --- | --- | --- | --- | --- | --- |
| Tissue Culture | Positive | Negative | Total | Positive | Negative | Total |
| Positive | 63 | 10 | 73 | 38 | 27 | 65 |
| Negative | 18* | 229 | 247 | 1 | 254 | 255 |
| Total | 81 | 239 | 320 | 39 | 281 | 320 |
| | | | 95% CI | | | 95% CI |
| Sensitivity | 63/73 | 86.3% | 76.3 – 93.2% | 38/65 | 58.5% | 45.6 – 70.6% |
| Specificity | 229/247 | 92.7% | 88.7 – 95.6% | 254/255 | 99.6% | 97.8 - 100% |
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- NOTE: 7 samples were TRU FLU A+B+ and positive for influenza B by tissue culture. TRU FLU A+B+ tests were not repeated during the clinical trials. TRU FLU A+B+ tests are considered suspect without repeat testing.
N. Proposed labeling: The labeling is sufficient and it satisfies the requirement of 21 CFR Part 809.10.
O. Conclusion: The submitted material in this premarket notification is complete and supports a substantial equivalence decision.
