← Product Code [PSZ](/submissions/MI/subpart-d%E2%80%94serological-reagents/PSZ) · K041439

# SAS INFLUENZA B TEST (K041439)

_Sa Scientific, Inc. · PSZ · Jul 22, 2004 · Microbiology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/PSZ/K041439

## Device Facts

- **Applicant:** Sa Scientific, Inc.
- **Product Code:** [PSZ](/submissions/MI/subpart-d%E2%80%94serological-reagents/PSZ.md)
- **Decision Date:** Jul 22, 2004
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 866.3328
- **Device Class:** Class 2
- **Review Panel:** Microbiology

## Indications for Use

SAS™ Influenza B Test is a visual and rapid assay for the presumptive qualitative detection of Influenza Type B antigens from nasal washes and aspirates. Negative results should be confirmed via culture. This test is not intended for the detection of Influenza Type A or C viral antigen.

## Device Story

Lateral flow immunochromatographic assay for qualitative detection of Influenza Type B nucleoprotein antigens. Input: nasal wash or aspirate specimens. Process: specimen extraction followed by application to test device; viral nucleoproteins bind to antibody-gold conjugate; complex migrates and is captured by membrane-bound antibodies; forms 'sandwich' immuno-complex. Output: visible pink line in specimen zone indicates positive result; pink control line indicates procedural validity. Used in clinical settings by professional staff. Provides rapid (15-minute) presumptive results to assist clinical decision-making; negative results require confirmation via cell culture.

## Clinical Evidence

Prospective multi-center clinical study (n=255) comparing SAS™ Influenza B Test to cell culture/DFA. Results: 90.5% sensitivity (95% CI: 71.1%–97.4%), 100% specificity (95% CI: 98.4%–100%), and 99.2% overall agreement. Analytical performance included reproducibility (100%) and specificity testing against 15 bacterial and 21 viral respiratory strains.

## Technological Characteristics

Lateral flow immunochromatographic assay. Utilizes monoclonal antibodies against Influenza Type B viral nucleoproteins. Gold-conjugated antibody detection system. Visual readout via colored lines. Internal procedural quality controls included.

## 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

- Binax™ NOW® Flu B Test ([K021649](/device/K021649.md))

## Submission Summary (Full Text)

> This content was OCRed from public FDA records by [Innolitics](https://innolitics.com). If you use, quote, summarize, crawl, or train on this content, cite Innolitics at https://innolitics.com.
>
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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY DEVICE ONLY TEMPLATE

A. 510(k) Number:
K041439

B. Purpose for Submission:
New device clearance

C. Analyte:
Influenza Type B nucleoprotein antigens

D. Type of Test:
Lateral flow immunochromatographic assay

E. Applicant:
SA Scientific, Inc.

F. Proprietary and Established Names:
SAS Influenza B Test, SAS FluB Test

G. Regulatory Information:
1. Regulation section:
21 CFR Part 866.3330
2. Classification:
Antigens, CF (including CF Control), Influenza virus A, B, C
3. Product Code:
GNX
4. Panel:
83 Microbiology

H. Intended Use:
1. Intended use(s):
SAS™ Influenza B Test is a visual and rapid assay for the presumptive qualitative detection of Influenza Type B antigens from nasal washes and aspirates. Negative results should be confirmed via cell culture. This test is not intended for the detection of Influenza Type A or C viral antigen. This test is for professional use only.
2. Indication(s) for use:
NA
3. Special condition for use statement(s):
The device is for prescription use only

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4. Special instrument Requirements: NA

I. Device Description:

The SAS™ Influenza B test utilizes monoclonal antibodies against Influenza Type B viral nucleoproteins. The test begins with an extraction of Type B nucleoproteins. Extracted specimens are then added to the test device. If type B nucleoproteins are present they bind to the antibody- gold conjugate in the test membrane and form a complex. This complex migrates across the membrane and is captured by Type B antibody in the membrane. Thus, in the presence of Influenza Type B nucleoproteins, a "whole sandwich" immuno-complex is formed and a visible, pink colored line develops in the specimen zone of the test device. In the absence of an Influenza Type B antigen, a "sandwich" immuno-complex is not formed and a negative result is indicated. To serve as a procedural control, a pink colored control line should appear in the control zone regardless of the presence or absence of Influenza Type B nucleoproteins.

The device is provided in kit form, the contents are as follows.

Test Devices.

Extraction buffer.

Disposable extraction tubes and filter tips.

Package insert.

J. Substantial Equivalence Information:

1. Predicate device name(s): Binax™ NOW® Flu B Test (K021649) manufactured by Binax™ Inc., Portland, Maine.

2. Predicate K number(s): K021469

3. Comparison with predicate:

|   | Viral Culture | Binax™ NOW® Flu B | SAS™ Influenza B Test  |
| --- | --- | --- | --- |
|  Format | Viral Culture | Lateral Flow | Lateral Flow  |
|  Cassette | N/A |  |   |
|  Antibodies | Monoclonal antibody | Antibodies to nucleoprotein | Monoclonal antibodies to nucleoprotein  |
|  Sample Type | Nasopharyngeal Specimens | Nasopharyngeal Specimens | Nasopharyngeal Specimens  |

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|  Sample Size | 200 μl | 100 μl | 150 μl  |
| --- | --- | --- | --- |
|  Method of Detection | CPE Immunofluorescence | Latex | Colloidal Gold  |
|  Assay Time | 24-48 hours | 15 minutes | 15 Minutes  |

## K. Standard/Guidance Document Referenced (if applicable): NA

## L. Test Principle:

The test begins with an extraction of Type B nucleoproteins. Extracted specimens are then added to the test device. If type B nucleoproteins are present they bind to the antibody- gold conjugate in the test membrane and form a complex. This complex migrates across the membrane and is captured by Type B antibody in the membrane. Thus, in the presence of Influenza Type B nucleoproteins, a "whole sandwich" immuno-complex is formed and a visible, pink colored line develops in the specimen zone of the test device. In the absence of an Influenza Type B antigen, a "sandwich" immuno-complex is not formed and a negative result is indicated. To serve as a procedural control, a pink colored control line should appear in the control zone regardless of the presence or absence of Influenza Type B nucleoproteins.

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

### 1. Analytical performance:

#### a. Precision/Reproducibility:

The reproducibility of the SAS™ Influenza B Test was evaluated in three clinical laboratories. The SAS™ Influenza B Test was tested against a panel of five (5) specimens of which included two (2) levels of positives and three (3) negatives over three days by three (3) laboratory personnel. The low and medium positive were from the Influenza B H1N1 strain. Negatives were comprised of sample extraction buffer, Streptococcus Group B and Influenza A Aichi strain. The overall reproducibility for the SAS™ Influenza B Test was 100%.

#### b. Linearity/assay reportable range: NA

#### c. Traceability, Stability, Expected values (controls, calibrators, or method): NA

#### d. Detection limit:

The limit of detection (LOD) or the SAS™ Influenza B Test was determined for five (5) Influenza B Viral Strains.

|  Influenza B Viral Strain | ATCC | Concentration TCID_{50}/0.2 ml  |
| --- | --- | --- |
|  B/Lee/40 | VR101 | 1.2 x 10^{5}  |
|  B/Allen/45 | VR102 | 5.6 x 10^{2}  |

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|  B/Mass/3/66 | VR523 | 3.2 x 10³  |
| --- | --- | --- |
|  B/Taiwan/2/62 | VR295 | 7.9 x 10³  |
|  B/Maryland/1/59 | VR296 | 4.5 x 10⁵  |

**e. Analytical specificity:**

To confirm the analytical specificity of the SAS™ Influenza B Test, fifteen (15) bacterial and twenty-one (21) viral strains likely to be found in the respiratory tract were tested. Bacterial cultures were tested at 1 x 10⁸ cfu/ml and the viral cultures at 5.6 x 10³ to 5.6 x 10⁶ TCID₅₀/0.2 ml. All yielded negative results.

**f. Assay cut-off:**

NA

**2. Comparison studies:**

**a. Method comparison with predicate device:**

Multiple clinical sites tested two hundred fifty-five (255) clinical specimens blindly and prospectively using the SAS™ Influenza B Test and Cell Culture or DFA. The SAS™ Influenza B tests and Cell Culture had an overall agreement of 99%.

|   |  | Cell Culture/DFA  |   |   |
| --- | --- | --- | --- | --- |
|   |  | + | - |   |
|  SAS Influenza B Test | + | 19 | 0 | 19  |
|   |   |  2 | 234 | 236  |
|   |   |  21 | 234 | 255  |

Sensitivity (19/21) x 100 = 90.5% (95% CI, 71.1% to 97.4%)
Specificity (234/234) x 100 = 100% (95% CI, 98.4% to 100%)
Agreement (253/255) x 100 = 99.2% (95%CI, 97.2% to 99.8%)

**b. Matrix comparison:**

NA

**3. Clinical studies:**

**a. Clinical sensitivity:**

Multiple clinical sites tested two hundred fifty-five (255) clinical specimens blindly and prospectively using the SAS™ Influenza B Test and Cell Culture or DFA. The SAS™ Influenza B tests and Cell Culture had an overall agreement of 99%.

|   |  | Cell Culture/DFA  |   |   |
| --- | --- | --- | --- | --- |
|   |  | + | - |   |
|  SAS Influenza B Test | + | 19 | 0 | 19  |
|   |   |  2 | 234 | 236  |
|   |   |  21 | 234 | 255  |

Sensitivity (19/21) x 100 = 90.5% (95% CI, 71.1% to 97.4%)

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Specificity (234/234) x 100 = 100% (95% CI, 98.4% to 100%)

Agreement (253/255) x 100 = 99.2% (95%CI, 97.2% to 99.8%)

b. Clinical specificity:
See above

c. Other clinical supportive data (when a and b are not applicable):
NA

4. Clinical cut-off:
NA

5. Expected values/Reference rang
The number of influenza virus infections varies from year to year, and they primarily occur during the fall and winter months. Many factors contribute to the rate of positivity, which include test method, geography, disease prevalence in the community and sampling method. Influenza B infections occur less than that of Influenza A. The multiple center clinical trial conducted over 2003 and 2004 Influenza Season had a prevalence of 8% when compared to cell culture/DFA and 7% when compared to SAS™ Influenza B Test results.

A. Conclusion:
The submitted material in this premarket notification is complete and supports a substantial equivalence decision.

---

**Source:** [https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/PSZ/K041439](https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/PSZ/K041439)

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