K Number
K041441
Date Cleared
2004-07-22

(51 days)

Product Code
Regulation Number
866.3328
Panel
MI
Reference & Predicate Devices
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

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

Device Description

The SASTM Influenza A test utilizes a set monoclonal antibodies against Influenza Type A viral nucleoproteins. The SASTM Influenza test begins with an extraction of Type A nucleoproteins. After the extraction has been completed, the sample is placed into the test and observed for the formation of colored lines. The specimen is absorbed and migrates via capillary action through a membrane that contains dried gold conjugated antibody, which is specific for Influenza Type A nucleoproteins. If Type A nucleoproteins are present, a "half-sandwich" immuno-complex is formed. The membrane contains immobilized antibody to Influenza Type A nucleoproteins, which binds the "half sandwich" complex. Thus, in the presence of Influenza 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 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 will always appear in the control zone regardless of the presence or absence of Influenza nucleoproteins.

AI/ML Overview

Here's an analysis of the provided text regarding the SAS™ Influenza A Test, focusing on the acceptance criteria and the supporting study:

The provided document describes a 510(k) submission for the SAS™ Influenza A Test. It claims substantial equivalence to a predicate device, the Binax™ NOW® Flu A Test, based on performance with freshly collected nasal wash specimens.

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are implicitly defined by demonstrating substantial equivalence to the predicate device. The performance of the SAS™ Influenza A Test is reported in comparison to the predicate.

Acceptance Criteria / Performance MetricSAS™ Influenza A Test (Reported Performance)
Detection of Influenza Type A antigensSubstantially equivalent to predicate device
Cross-reactivityNone with tested viral and bacterial strains
InterferenceNone with tested viral and bacterial strains

Note: The document focuses on showing substantial equivalence and mentions "Performance Summary: The SAS™ Influenza A test performed substantially equivalent to the predicate device, Binax™ NOW® Flu A test. This was verified by comparison to freshly collected nasal wash specimens." Specific metrics like sensitivity, specificity, or agreement rates are not explicitly provided within this summary, but are inferred to be comparable to the predicate for substantial equivalence.

2. Sample Size Used for the Test Set and the Data Provenance

  • Test Set Sample Size: The document does not explicitly state the numerical sample size used for the comparison study. It only mentions "freshly collected nasal wash specimens."
  • Data Provenance: The document does not explicitly state the country of origin. It can be inferred that the study was conducted to support a US FDA 510(k) submission, suggesting it was likely conducted in the US or under US regulatory standards. The study design is prospective, as it used "freshly collected nasal wash specimens."

3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts

  • Number of Experts: Not specified.
  • Qualifications of Experts: The ground truth for positive influenza A cases was "confirmed via culture." The document does not specify who performed or interpreted these cultures, or their qualifications.

4. Adjudication Method for the Test Set

The document does not describe any specific adjudication method for reconciling discordant results between the SAS™ Influenza A Test, the predicate device, and the culture confirmation.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs without AI Assistance

This question is not applicable to this device. The SAS™ Influenza A Test is an in vitro diagnostic immunoassay that provides a visual result (colored lines) and does not involve human readers interpreting complex images or AI assistance.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

This question is not applicable to this device. It is a rapid immunoassay, a "standalone" device in the sense that it produces a result directly without requiring an additional algorithm or human interpretation beyond observing the presence or absence of colored lines.

7. The Type of Ground Truth Used

The ground truth used for positive cases was culture confirmation. Specifically, "Negative results should be confirmed via culture." and "confirmed via culture." for positive cases.

8. The Sample Size for the Training Set

This question is not applicable to this device. The SAS™ Influenza A Test is a rapid immunoassay that utilizes monoclonal antibodies and immunochromatographic technology. It is not an algorithm or AI-based device that requires a "training set."

9. How the Ground Truth for the Training Set Was Established

This question is not applicable for the same reasons as point 8. No training set was used.

§ 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.