← Product Code [PSZ](/productcode/PSZ) · K080380

# SAS INFLUENZA A & B TEST (K080380)

_Sa Scientific, Inc. · PSZ · Jul 23, 2009 · Microbiology · SESE_

**Canonical URL:** https://fda.innolitics.com/device/K080380

## Device Facts

- **Applicant:** Sa Scientific, Inc.
- **Product Code:** [PSZ](/productcode/PSZ.md)
- **Decision Date:** Jul 23, 2009
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 866.3328
- **Device Class:** Class 2
- **Review Panel:** Microbiology
- **Attributes:** Real-World Evidence

## Real-World Evidence

| Submission | Device | Sponsor | RWD Sources | RWE Use Summary | Key Tags |
| --- | --- | --- | --- | --- | --- |
| K080380 · Jul 23, 2009 | SAS INFLUENZA A & B TEST | Sa Scientific, Inc. | Archived clinical nasal wash samples from a children's hospital | A retrospective study was conducted using 191 frozen, archived nasal wash samples to supplement the prospective clinical performance data by comparing the combined device to the individual predicate devices. | Retrospective study; Archived specimens; Clinical performance |

### Clinical Evidence

| Study Design | Population | Comparator | Key Endpoints |
| --- | --- | --- | --- |
| Retrospective, blinded comparison of archived samples | Patients at a children's hospital in Texas; Sample Size: 191; Number of Sites: 1 | Individual SAS Influenza A and B Tests | Positive and negative percent agreement between the combined device and individual predicate devices |

## Indications for Use

SAS™ FluAlert A & B Test is a visual and rapid assay for the presumptive in-vitro qualitative detection of influenza A and influenza B viral nucleoprotein antigens from nasal washes and nasal aspirates of symptomatic patients. The test is not intended for the detection of Influenza Type C viral antigen. This test is for professional use only. Negative results do not preclude infection with influenza A or B and should not be used as the sole basis for treatment or other patient management decisions. It is recommended that negative results be confirmed by cell culture.

## Device Story

The SAS™ FluAlert A & B Test is a rapid, visual, lateral-flow immunoassay for professional use in clinical settings. It processes nasal wash or nasal aspirate samples to detect influenza A and B viral nucleoproteins. The device utilizes two separate test strips housed in a single side-by-side plastic cassette. Sample extraction occurs before application to the test wells. The assay relies on capillary action to migrate the sample across membranes containing gold-conjugated antibodies. If influenza antigens are present, a 'whole sandwich' immunocomplex forms, resulting in a visible pink line in the specimen zone. A procedural control line appears on each strip to verify proper flow. The test provides qualitative results to assist clinicians in patient management, though negative results do not rule out infection and require confirmation via cell culture.

## Clinical Evidence

Prospective clinical study (n=461) and retrospective study (n=191) compared combined device to individual predicates. Prospective study showed 97.2% positive agreement and 99.7% negative agreement for Influenza A; 98.7% positive agreement and 99.7% negative agreement for Influenza B. Historical clinical sensitivity/specificity for individual tests vs. cell culture/DFA: Influenza A (76% sensitivity, 97.9% specificity); Influenza B (90.5% sensitivity, 100% specificity).

## Technological Characteristics

Lateral-flow immunochromatographic assay. Utilizes gold-conjugated antibodies specific to influenza A and B nucleoproteins. Form factor is a side-by-side plastic cassette containing two test strips. Manual, point-of-care test requiring no external energy source or connectivity. Qualitative visual readout.

## Regulatory 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.

## Predicate Devices

- SAS™ Influenza A Test ([K044141](/device/K044141.md))
- SAS™ Influenza B Test ([K041439](/device/K041439.md))

## Submission Summary (Full Text)

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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

A. 510(k) Number:
K080380

B. Purpose for Submission:
New device, combining the immunoassay test strips from the individual SAS™ Influenza A and SAS™ Influenza B Tests into one side-by-side plastic cassette

C. Measurand:
Influenza A and influenza B viral nucleoprotein antigens
Influenza types detected: influenza A and influenza B

D. Type of Test:
A rapid immunoassay for the qualitative detection of influenza A and influenza B viral nucleoprotein in nasal washes and nasal aspirates

E. Applicant:
SA Scientific, Ltd.

F. Proprietary and Established Names:
SAS™ FluAlert A & B Test

G. Regulatory Information:

|  Product Code | Classification | Regulation Section | Panel  |
| --- | --- | --- | --- |
|  GNX | Class II | 21 CFR 866.3330
Antigens, Cf (including
Cf controls) influenza
virus A, B, C | Microbiology (83)  |

H. Intended Use:

1. Intended use(s):
SAS™ FluAlert A & B Test is a visual and rapid assay for the presumptive in-vitro qualitative detection of influenza A and influenza B viral nucleoprotein antigens from nasal washes and nasal aspirates of symptomatic patients. The test is not intended for the detection of Influenza Type C viral antigen. This test is for professional use only.

Negative results do not preclude infection with influenza A or B and should not be used as the sole basis for treatment or other patient management decisions. It is recommended that negative results be confirmed by cell culture.

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2. Indication(s) for use:
Same as Intended Use

3. Special conditions for use statement(s):
For prescription use only

4. Special instrument requirements:
N/A

I. Device Description:
The SAS™ FluAlert A & B Test is an immunoassay comprised of two strips in one cassette. One strip utilizing monoclonal antibodies against influenza type A nucleoproteins and the second strip utilizing influenza type B viral nucleoproteins. In the presence of influenza A and/or influenza B, the antibody-gold conjugate in the test membranes binds to the nucleoproteins and forms a complex. This complex migrates across the membrane and is captured by influenza A or influenza B antibodies in the membrane and forms visible pink lines. To serve as a procedural control, a pink line will always appear in the control zone of each strip regardless of the presence or absence of influenza A or influenza B nucleoproteins.

J. Substantial Equivalence Information:

1. Predicate device name(s):
SAS™ Influenza A Test (K044141) and SAS™ Influenza B Test (K041439), manufactured by SA Scientific, Ltd., San Antonio, TX.

2. Predicate K number(s):
K044141
K041439

3. Comparison with predicate:

|  Similarities  |   |   |   |
| --- | --- | --- | --- |
|  Item | Device | Predicate 1 | Predicate 2  |
|   | The SAS™ FluAlert A & B Test | SAS™ Influenza A Test (K044141) | SAS™ Influenza B Test (K041439)  |
|  Technology | Immunoassay | Immunoassay | Immunoassay  |
|  Organism Detected | Influenza A and B | Influenza A | Influenza B  |
|  Intended Use | Detection of influenza A and B viral nucleoproteins | Detection of influenza A viral nucleoproteins | Detection of influenza B viral nucleoproteins  |

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|  Differences  |   |   |   |
| --- | --- | --- | --- |
|  Item | Device | Predicate 1 | Predicate 2  |
|   | The SAS™ FluAlert A & B Test | SAS™ Influenza A Test (K044141) | SAS™ Influenza B Test (K041439)  |
|  Device Configuration | Two strips in a cassette for detection of influenza A and influenza B | One strip in a cassette for detection of influenza A | One strip in a cassette for detection of influenza B  |

K. Standard/Guidance Documents Referenced (if applicable):
Guidance on In Vitro Diagnostic Devices to Detect Influenza A Viruses: Labeling and Regulatory Path - http://www.fda.gov/cdrh/oivd/guidance/1594.pdf.

L. Test Principle:
The SAS™ FluAlert A & B Test utilizes monoclonal antibodies against influenza Type A and influenza Type B viral nucleoproteins. The test begins with an extraction of nucleoproteins from the clinical specimen. The extracted specimen is then placed into two separate sample wells and observed for the formation of colored lines. The specimen is absorbed and migrates via capillary action through membranes that contain dried gold conjugated antibody specific for either influenza A or influenza B nucleoproteins. If Type A and/or Type B nucleoproteins are present, they bind to the antibody-gold conjugate and form a complex which migrates across the membrane and is captured by influenza A or influenza B antibodies in the membrane. Thus, in the presence of influenza A and influenza B nucleoproteins, an immuno-complex is formed and a visible pink line develops in the specimen zones of the test device, in the A line for influenza A and in the B line for influenza B. In the absence of influenza A and/or influenza B antigens, an immuno-complex is not formed and a negative result is indicated. To serve as a procedural control, a pink line should appear in the control zones regardless of the presence or absence of influenza A and influenza B nucleoproteins.

Interpretation of Results:

Expected Performance of Controls:

Internal Controls
Each test device includes an internal procedural control, a line in the C (control) regions of the test device. Correct procedural technique, specimen flow and test device performance is confirmed when a colored line appears in the C areas of the membrane. If the colored line fails to appear in the C area of either strip, the test result is invalid.

A clear background is an internal negative procedural control. The background color should be white to light pink and should not interfere with the reading of the test result. If a more intensely red background color appears, it may

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interfere with the ability to read the test result, therefore the test should be repeated.

## External Controls

Negative and Positive controls for influenza A antigen and influenza B antigen should be tested and the appropriate results obtained. External quality control testing should be performed in conformance with local, state and federal regulations or accreditation organizations as applicable, and should follow the user's laboratory's standard quality control procedures. Controls in the SAS™ FluAlert Control Kit, catalog # 046230, are ready to use; do not dilute with extraction buffer.

## Specimen Results and Interpretation:

- The test is negative if a colored line appears only in the C (control) area on both strips.
- The test is positive for Flu A if the line appears under S (specimen) on the Flu A strip and a second line appears under the C on both strips. The test is positive for Flu B if the line appears under S on the Flu B strip and a second line appears under C on both strips. Any pink colored line in the specimen (S) area, regardless of the intensity, is a positive result.
- While co-infections with both influenza A and influenza B viruses are rare and no incidences were observed in the clinical studies, they might occur. If there is a question about the test results, the test may be repeated.
- The test is invalid if no colored line appears in the C area on either strip, even if a colored line appears in either S area. If this occurs, the test should be repeated.

## M. Performance Characteristics (if/when applicable):

### 1. Analytical Performance:

#### a. Precision/Reproducibility:

The reproducibility of the SAS™ FluAlert A&B Test was evaluated at three clinical sites. Three or four non-professional users per site tested the SAS™ FluAlert A&B Test against a panel of approximately 30 aliquots each of six (6) panel members over a two-week period. Specimens were comprised of pooled nasal aspirates and included two (2) levels of positives for influenza A and two (2) for influenza B and one negative for each virus. The influenza A panel members contained H3N2 A/Hong Kong/8/68 and the influenza B panel members contained B/Allen/45. Negative specimens for influenza A and influenza B were in concentrations below the limit of detection.

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Reproducibility Study Summary for the SAS™ FluAlert A & B Test

|   | Panel Member | Influenza A High Negative | Influenza A Low Positive | Influenza A Moderate Positive | Influenza B High Negative | Influenza B Low Positive | Influenza B Moderate Positive  |
| --- | --- | --- | --- | --- | --- | --- | --- |
|   | Viral Titer Final Conc. TCID_{50}/0.2 ml | 1.8 x 10^{3} | 7 x 10^{3} | 1.4 x 10^{4} | 2.8 x 10^{2} | 1.1 x 10^{3} | 2.2 x 10^{3}  |
|  Agreement with Expected Result | Site 1 | 29 Neg/30 96.7% | 26 Pos/30 86.6% | 29 Pos/30 96.7% | 28 Neg/29 96.6% | 29 Pos/30 96.7% | 29 Pos/29 100%  |
|   |  Site 2 | 29 Neg/30 96.7% | 26 Pos/29 89.7% | 29 Pos/29 100% | 30 Neg/30 100% | 29 Pos/30 96.7% | 30 Pos/30 100%  |
|   |  Site 3 | 28 Neg/30 93.3% | 27 Pos/30 90.0% | 30 Pos/30 100% | 26 Neg/29 89.7% | 29 Pos/30 96.7% | 30 Pos/30 100%  |
|   | Total Agreement | 95.6% | 88.8% | 98.9% | 95.4% | 96.7% | 100%  |

b. Linearity/assay reportable range:

Not applicable, qualitative assay

c. Traceability, Stability, Expected values (controls, calibrators, or methods): N/A

d. Detection limit:

The Limit of Detection (LoD) for the SAS™ FluAlert A&amp;B Test was determined using quantified (TCID<sub>50</sub>/ml) cultures of five (5) each Influenza A and Influenza B viral strains received from the ATCC. Each strain was serially diluted in SAS™ FluAlert extraction buffer. Strains were assayed using the SAS™ FluAlert A&amp;B Test until no positive signal could be seen. LoD was calculated to determine the lowest detectable concentration range of influenza.

Limit of Detection Summary

|  Influenza Viral Strain | ATCC | LoD TCID_{50}/0.2 ml  |
| --- | --- | --- |
|  H1N1 A/PR/3/34 | VR-95 | 1.2 x 10^{5}  |
|  H3N2 A/Aichi/2/68 | VR-547 | 5.6 x 10^{2}  |
|  H3N2 A/Hong Kong/8/6/8 | VR-544 | 3.5 x 10^{3}  |
|  H1N1 A/FM/147 | VR-97 | 7.9 x 10^{3}  |
|  H3N2 A/Victoria/3/75 | VR-822 | 4.5 x 10^{5}  |
|  Influenza B/Lee/40 | VR-101 | 9.9 x 10^{4}  |
|  Influenza B/Allen/45 | VR-102 | 5.6 x 10^{2}  |
|  Influenza B/Mass/3/66 | VR-523 | 4.5 x 10^{2}  |
|  Influenza B/Taiwan/2/62 | VR-295 | 3.5 x 10^{1}  |
|  Influenza B/Maryland/1/59 | VR-296 | 1.6 x 10^{2}  |

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# e. Analytical specificity:

Analytical specificity of the SAS™ FluAlert A&amp;B Test was evaluated for potential cross-reactivity and interference with non-influenza pathogens associated with respiratory tract infections.

# Cross-Reactivity Evaluation

Twenty-two virus strains were obtained from ATCC or other commercial sources. Each cultured viral strain was tested on the SAS™ FluAlert A&amp;B Test at concentrations listed in the table below.

Cross-reactivity Test Results with Common Viral Respiratory Pathogens

|  Virus | ATTC/Lot # | Concentration | “A” portion of the SAS™ FluAlert A&B | “B” portion of the SAS™ FluAlert A&B  |
| --- | --- | --- | --- | --- |
|  Adenovirus 5 | 10-198-000 | 1.2 x 1010 TCID50 /0.2 ml | Neg | Neg  |
|  Adenovirus 7 | VR7 | 3.2 x 103 TCID50 /0.2 ml | Neg | Neg  |
|  Adenovirus 10 | VR1087 | 3.2 x 103 TCID50 /0.2 ml | Neg | Neg  |
|  CoxsackieA9 | VR186 | 3.2 x 102 TCID50 /0.2 ml | Neg | Neg  |
|  CoxsackieB5 | VR185 | 3.2 x 106 TCID50 /0.2 ml | Neg | Neg  |
|  Cytomegalovirus | 021301 | 20 μg/ml | Neg | Neg  |
|  Echovirus11 | VR1052 | NA | Neg | Neg  |
|  Echovirus3 | VR1040 | 1 x 104 TCID50 /0.2 ml | Neg | Neg  |
|  Echovirus 6 | VR1044 | 3.2 x 106 TCID50 /0.2 ml | Neg | Neg  |
|  HSV-1 | 2J30000 | 15 μg/ml | Neg | Neg  |
|  HSV-2 | 8J29502 | 15 μg/ml | Neg | Neg  |
|  Varicella zoster | 1102097 | 12 μg/ml | Neg | Neg  |
|  Parainfluenza 1 | VR907 | 5.6 x 106 TCID50 /0.2 ml | Neg | Neg  |
|  Parainfluenza 2 | VR92 | 1.8 x 105 TCID50 /0.2 ml | Neg | Neg  |
|  Parainfluenza 3 | VR93 | 3.2 x 106 TCID50 /0.2 ml | Neg | Neg  |
|  RSV Long | VR26 | 0.1 x 105.5 TCID50 /0.2 ml | Neg | Neg  |
|  RSV B | VR1400 | 0.1 x 105.25 TCID50 /0.2 ml | Neg | Neg  |
|  Influenza B Allen | VR102 | 3.2 x 103 TCID50 /0.2 ml | Neg |   |
|  Influenza B Lee | VR101 | 3.2 x 106 TCID50 /0.2 ml | Neg |   |
|  Influenza B Mass | VR523 | 1.8 x 103 TCID50 /0.2 ml | Neg |   |
|  Influenza B Maryland | VR296 | 1 x 104 TCID50 /0.2 ml | Neg |   |
|  Influenza B Taiwan | VR295 | 5.6 x 102 TCID50 /0.2 ml | Neg |   |
|  Influenza A (H1N1) PR | VR95 | 1.8 x 104 TCID50 /0.2 ml |  | Neg  |
|  Influenza A (H3N2) Aichci | VR547 | 1.8 x 106 TCID50 /0.2 ml |  | Neg  |
|  Influenza A | VR544 | 5.6 x 104 TCID50 /0.2 ml |  | Neg  |

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One yeast and fourteen bacterial strains were obtained from ATCC or other commercial sources. Each cultured bacterial or yeast strain was diluted to a concentration of 1x10⁸ cfu/ml and tested on the SAS™ FluAlert A&amp;B Test.

## Cross-reactivity Test Results with Common Bacterial Respiratory Pathogens

|  Bacteria or Yeast | “A” portion of the SAS™ FluAlert A&B | “B” portion of the SAS™ FluAlert A&B  |
| --- | --- | --- |
|  Candida albicans | Neg | Neg  |
|  Chlamydia trachomatis | Neg | Neg  |
|  Corynebacterium diphtheriae | Neg | Neg  |
|  Haemophilus influenza | Neg | Neg  |
|  Klebsiella pneumoniae | Neg | Neg  |
|  Serratia marcescens | Neg | Neg  |
|  Staphylococcus epidermidis | Neg | Neg  |
|  Staphylococcus aureus | Neg | Neg  |
|  Streptococcus sp gr A | Neg | Neg  |
|  Streptococcus sp gr F | Neg | Neg  |
|  Streptococcus sp gr G | Neg | Neg  |
|  Streptococcus pneumoniae | Neg | Neg  |
|  Mycoplasma pneumoniae | Neg | Neg  |
|  Neisseria meningitidis | Neg | Neg  |
|  Pseudomonas aeruginosa | Neg | Neg  |

The study demonstrated that the SAS™ FluAlert A&amp;B Test did not cross-react with any respiratory pathogens or commensal organisms tested. The data demonstrated 100% concordance with the expected results.

## Interference Study

The analytical specificity of the influenza A portion of the SAS™ FluAlert A&amp;B was evaluated by testing a panel of 22 viruses, 14 bacteria, and one yeast species which may be found in the respiratory tract. For the influenza A portion of the test, influenza whole virus strain A/FM/147 (ATCC VR97) at a titer of 7.9 x 10³ TCID₅₀/0.2 ml was added to viral cultures and viral antigens at the concentrations listed in the table below and bacterial and yeast cultures at concentrations of 1 x 10⁸ cfu/ml. For the influenza B portion of the test, whole virus strain B/Mass/3/66 (ATCC VR523) at a titer of 3.2 x 10³ TCID₅₀/0.2 ml was added to viral cultures in the concentrations listed in the table below and bacterial and yeast cultures at 1 x 10⁸ cfu/ml.

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SAS™ FluAlert A&amp;B Interference Test Results

|  Virus | ATTC/Lot # | Concentration | “A” Portion of the SAS™ FluAlert A&B | “B” Portion of the SAS™ FluAlert A&B  |
| --- | --- | --- | --- | --- |
|  Adenovirus 5 | 10-198-000 | 1.2 x 10^{10} TCID_{50} /0.2 ml | Pos | Pos  |
|  Adenovirus 7 | VR7 | 3.2 x 10^{3} TCID_{50} /0.2 ml | Pos | Pos  |
|  Adenovirus 10 | VR1087 | 3.2 x 10^{3} TCID_{50} /0.2 ml | Pos | Pos  |
|  CoxsackieA9 | VR186 | 3.2 x 10^{2} TCID_{50} /0.2 ml | Pos | Pos  |
|  CoxsackieB5 | VR185 | 3.2 x 10^{6} TCID_{50} /0.2 ml | Pos | Pos  |
|  Cytomegalovirus | 021301 | 20 μg/ml | Pos | Pos  |
|  Echovirus11 | VR1052 | NA | Pos | Pos  |
|  Echovirus3 | VR1040 | 1 x 10^{4} TCID_{50} /0.2 ml | Pos | Pos  |
|  Echovirus6 | VR1044 | 3.2 x 10^{6} TCID_{50} /0.2 ml | Pos | Pos  |
|  HSV-1 | 2J30000 | 15 μg/ml | Pos | Pos  |
|  HSV-2 | 8J29502 | 15 μg/ml | Pos | Pos  |
|  Varicella zoster | 1102097 | 12 μg/ml | Pos | Pos  |
|  Parainfluenza 1 | VR907 | 5.6 x 10^{6} TCID_{50} /0.2 ml | Pos | Pos  |
|  Parainfluenza 2 | VR92 | 1.8 x 10^{5} TCID_{50} /0.2 ml | Pos | Pos  |
|  Parainfluenza 3 | VR93 | 3.2 x 10^{6} TCID_{50} /0.2 ml | Pos | Pos  |
|  RSV Long | VR26 | 0.1 x 10^{3.5} TCID_{50} /0.2 ml | Pos | Pos  |
|  RSV B | VR1400 | 0.1 x 10^{5.25} TCID_{50} /0.2 ml | Pos | Pos  |
|  Influenza B Allen | VR102 | 3.2 x 10^{3} TCID_{50} /0.2 ml | Pos |   |
|  Influenza B Lee | VR101 | 3.2 x 10^{6} TCID_{50} /0.2 ml | Pos |   |
|  Influenza B Mass | VR523 | 1.8 x 10^{3} TCID_{50} /0.2 ml | Pos |   |
|  Influenza B Maryland | VR296 | 1 x 10^{4} TCID_{50} /0.2 ml | Pos |   |
|  Influenza B Taiwan | VR295 | 5.6 x 10^{2} TCID_{50} /0.2 ml | Pos |   |
|  Influenza A (H1N1) PR | VR95 | 1.8 x 10^{4} TCID_{50} /0.2 ml |  | Pos  |
|  Influenza A (H3N2) Aichci | VR547 | 1.8 x 10^{6} TCID_{50} /0.2 ml |  | Pos  |
|  Influenza A (H3N2) Hong Kong | VR544 | 5.6 x 10^{4} TCID_{50} /0.2 ml |  | Pos  |
|  Influenza A FM | VR97 | 3.2 x 10^{4} TCID_{50} /0.2 ml |  | Pos  |
|  Influenza A (H3N2) Victoria | VR822 | 1.8 x 10^{6} TCID_{50} /0.2 ml |  | Pos  |

One yeast and fourteen bacterial strains were obtained from ATCC or other commercial sources. Each cultured bacterial or yeast strain was diluted to a concentration of $1 \times 10^{8}$ cfu/ml and tested on the SAS™ FluAlert A&amp;B Test.

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SAS™ FluAlert A&amp;B Interference Test Results

|  Bacteria or Yeast | “A” portion of the SAS™ FluAlert A&B | “B” portion of the SAS™ FluAlert A&B  |
| --- | --- | --- |
|  Candida albicans | Pos | Pos  |
|  Chlamydia trachomatis | Pos | Pos  |
|  Corynebacterium diphtheriae | Pos | Pos  |
|  Haemophilus influenza | Pos | Pos  |
|  Klebsiella pneumoniae | Pos | Pos  |
|  Serratia marcescens | Pos | Pos  |
|  Staphylococcus epidermidis | Pos | Pos  |
|  Staphylococcus aureus | Pos | Pos  |
|  Streptococcus sp gr A | Pos | Pos  |
|  Streptococcus sp gr F | Pos | Pos  |
|  Streptococcus sp gr G | Pos | Pos  |
|  Streptococcus pneumoniae | Pos | Pos  |
|  Mycoplasma pneumoniae | Pos | Pos  |
|  Neisseria meningitidis | Pos | Pos  |
|  Pseudomonas aeruginosa | Pos | Pos  |

f. Assay cut-off:

N/A

2. Comparison studies:

a. Method comparison with predicate device:

Prospective Clinical Study

The SAS™ FluAlert A&amp;B Test combines the immunoassay test strips from the individual SAS™ Influenza A and SAS™ Influenza B Tests into one side-by-side plastic cassette. There are no other changes made to this test. In these studies, the users compared the combined test to the individual tests for evaluation of user interpretations. Please see: “Results Summary: SAS™ Influenza A and SAS™ Influenza B Individual Devices compared to cell culture or DFA” chart for comparison of the individual tests to cell culture/DFA.

Four clinical trial sites, in Texas and South Dakota, tested four hundred sixty one (461) nasal clinical specimens blindly and prospectively comparing the SAS™ Influenza A Test and The SAS™ FluAlert A&amp;B (combined) Test performance. The SAS™ Influenza A Test and SAS™ FluAlert A&amp;B Test had a positive percent agreement of 97.2% and a negative percent agreement of 99.7%. Thirteen samples yielded invalid results.

Four clinical trial sites, in Texas and South Dakota, tested four hundred

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sixty one (461) nasal clinical specimens blindly and prospectively comparing the SAS™ Influenza B Test and the SAS™ FluAlert A&amp;B (combined) Test performance. The SAS™ Influenza B test and SAS™ FluAlert A&amp;B Test had a positive percent agreement of 98.7% and a negative percent agreement of 99.7%.

Clinical sites collected the nasal wash samples during the 2007-2008 and 2008 – 2009 influenza seasons from an approximately equal mix of adult (&gt;21 years) and pediatric patients (0-21 years). The nasal aspirate samples were collected predominately from pediatric patients.

Demographics of fresh specimens:

|  Age (years) | Number of Nasal Wash specimens | % of Total NW Specimens | Number of Nasal Aspirate Specimens | % of Total NA Specimens  |
| --- | --- | --- | --- | --- |
|  0-5 | 16 | 5.7% | 73 | 40.1%  |
|  6-21 | 21 | 7.5% | 108 | 59.3%  |
|  22 - 65 | 25 | 9.0% | 1 | 0.6%  |
|  >65 | 9 | 3.2% | 0 |   |
|  Not Determined | 208 | 74.5% | 0 |   |
|  Total | 279 |  | 182 |   |

# Fresh, Prospective Nasal Aspirates:

Influenza A Comparison Results

SAS™ Influenza A Test

|   | + | - |   |
| --- | --- | --- | --- |
|  + | 44 | 0 | 44  |
|  - | 1 | 137 | 138  |
|   | 45 | 137 | 182  |

Positive % Agreement: 97.8% (95% CI 87-100%)
Negative % Agreement: 100% (97% CI 95-100%)

Influenza B Comparison Results

SAS™ Influenza B Test

|   | + | - |   |
| --- | --- | --- | --- |
|  + | 37 | 0 | 37  |
|  - | 0 | 145 | 145  |
|   | 37 | 145 | 182  |

Positive % Agreement: 100% (95% CI 97-100%)
Negative % Agreement: 100% (95% CI 88-100%)

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# Fresh, Prospective Nasal Washes:

Influenza A Comparison Results

SAS™ Influenza A Test

|   | + | - |   |
| --- | --- | --- | --- |
|  + | 26 | 1 | 27  |
|  - | 1 | 251 | 252  |
|   | 27 | 252 | 279  |

Positive % Agreement: 96.3% (95% CI 79-100%)

Negative % Agreement: 99.6% (95% CI 97-100%)

Influenza B Comparison Results

SAS™ Influenza B Test

|   | + | - |   |
| --- | --- | --- | --- |
|  + | 40 | 1 | 41  |
|  - | 1 | 237 | 238  |
|   | 41 | 238 | 279  |

Positive % Agreement: 97.6% (95% CI 86-100%)

Negative % Agreement: 99.6% (95% CI 97-100%)

# Results Summary: Fresh Nasal Washes and Aspirates

Influenza A Comparison Results

SAS™ Influenza A Test

|   | + | - |   |
| --- | --- | --- | --- |
|  + | 70 | 1 | 71  |
|  - | 2 | 388 | 390  |
|   | 72 | 389 | 461  |

Positive % Agreement: 97.2% (95% CI 879-100%)

Negative % Agreement: 99.7% (95% CI 98-100%)

Influenza B Comparison Results

SAS™ Influenza B Test

|   | + | - |   |
| --- | --- | --- | --- |
|  + | 77 | 1 | 78  |
|  - | 1 | 382 | 383  |
|   | 78 | 383 | 461  |

Positive % Agreement: 98.7% (95% CI 92-100%)

Negative % Agreement: 99.7% (95% CI 98-100%)

Note: Performance characteristics for detecting the 2009 H1N1 influenza virus from human specimens have not been established

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12

# Retrospective Study

To supplement the prospective study, 191 frozen, archived, nasal wash samples from a children's hospital in Texas were blindly assayed comparing the individual SAS™ Influenza A Test and the individual SAS™ Influenza B Test to the SAS™ FluAlert A&amp;B (combined) Test. For these samples, the positive percent agreement with the influenza A Test is 100% and negative percent agreement is 99.3%, while positive percent agreement with the Influenza B Test was 94.7% and negative percent agreement is 98.0%

## SAS™ Influenza

### A Test

|   | + | - |   |
| --- | --- | --- | --- |
|  + | 27 | 1 | 28  |
|  - | 0 | 163 | 163  |
|   | 27 | 164 | 191  |

**Total**

Positive % Agreement: 100% (95% CI 84-100%)

Negative % Agreement: 99.3% (95% CI 96-100%)

## SAS™ Influenza B Test

|   | + | - |   |
| --- | --- | --- | --- |
|  + | 36 | 3 | 39  |
|  - | 2 | 150 | 152  |
|   | 38 | 153 | 191  |

**Positive % Agreement: 94.7% (95% CI 81-99%)**

Negative % Agreement: 98.0% (95% CI 94-99%)

b. Matrix comparison:

Not applicable

3. Clinical studies:

a and b. Clinical Sensitivity and Specificity:

**SAS™ Influenza A and SAS™ Influenza B individual devices compared to cell culture or DFA.**

The performance of the SAS™ Influenza A and SAS™ Influenza B individual devices was established during the 2002-2003 and 2003-2004 flu seasons, at clinical sites in Iowa, Virginia, and South Dakota. A total of 263 and 255 clinical specimens, respectively, were tested using the SAS Influenza A and Influenza B devices and the results were compared to cell culture or DFA. Specimens were comprised of leftover nasopharyngeal

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washes, nasal washes and nasopharyngeal aspirates, and were tested blindly and prospectively. Results are shown in the following table.

|  All Specimens |   | SAS™ Influenza A Test |   |   | SAS™ Influenza B Test  |   |   |
| --- | --- | --- | --- | --- | --- | --- | --- |
|   |  | + | - |  | + | - |   |
|  Cell Culture/DFA | + | 57 | 4 | 61 | 19 | 0 | 19  |
|   |  - | 18 | 184 | 202 | 2 | 234 | 236  |
|   |  | 75 | 188 | 263 | 21 | 234 | 255  |
|  Sensitivity 95% CI | 76% 65-85% |   |   |  | 90.5% 68-98%  |   |   |
|  Specificity 95% CI | 97.9% 94-99.% |   |   |  | 100% 98-100%  |   |   |

4. Clinical cut-off:

Not applicable

5. Expected values/Reference range:

Influenza prevalence varies year to year, with the highest number of cases in the fall and winter months in the US. During the period of September 30, 2007 to April 5, 2008, prevalence in the US for both influenza A and influenza B was 18.5%, with 74% of those cases attributed to influenza A and 26% attributed to influenza B. For studies conducted on the SAS™ FluAlert A&amp;B Test, during the 2007-2008 and 2008-2009 seasons, prevalence for fresh, prospective nasal washes and nasal aspirates was 15.1% for influenza A and 16.5% for influenza B.

N. Proposed Labeling:

The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.

O. Conclusion:

The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

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**Source:** [https://fda.innolitics.com/device/K080380](https://fda.innolitics.com/device/K080380)

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