BINAXNOW INFLUENZA A & B TEST
Device Facts
| Record ID | K041049 |
|---|---|
| Device Name | BINAXNOW INFLUENZA A & B TEST |
| Applicant | Binax, Inc. |
| Product Code | PSZ · Microbiology |
| Decision Date | Aug 10, 2004 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 866.3328 |
| Device Class | Class 2 |
| Attributes | Real-World Evidence, Pediatric |
Real-World Evidence
| Submission | Device | Sponsor | RWD Sources | RWE Use Summary | Key Tags |
|---|---|---|---|---|---|
| K041049 · Aug 10, 2004 | BINAXNOW INFLUENZA A & B TEST | Binax, Inc. | Retrospective frozen clinical samples from symptomatic patients | Retrospective clinical samples were used to compare the performance of the new device against predicate devices (NOW Flu A and Flu B tests) to support substantial equivalence. | Retrospective samples; Clinical performance; Substantial equivalence |
Clinical Evidence
| Study Design | Population | Comparator | Key Endpoints |
|---|---|---|---|
| Retrospective comparison study | Symptomatic patients from physician offices, clinics, and hospitals (US and Sweden); Sample Size: 306 (Flu A) and 303 (Flu B) retrospective samples; Number of Sites: Multiple sites | NOW Flu A Test and NOW Flu B Test | Sensitivity and specificity |
Indications for Use
The BinaxNOW® Influenza A & B Test is an in vitro immunochromatographic assay for the qualitative detection of influenza A and B nucleoprotein antigens in nasopharyngeal swab and nasal wash/aspirate specimens. It is intended to aid in the rapid differential diagnosis of influenza A and B viral infections. Negative test results should be confirmed by culture.
Device Story
The BinaxNOW® Influenza A & B Test is an immunochromatographic membrane assay used in clinical settings to detect influenza A and B nucleoprotein antigens. Input consists of nasopharyngeal swabs or nasal wash/aspirate specimens. The sample is eluted into a solution and applied to a test strip housed in a book-shaped hinged cardboard device. The strip contains immobilized monoclonal antibodies that capture viral antigens; a blue control line confirms assay validity. Results are interpreted visually by a clinician or technician at 15 minutes based on the presence of pink-to-purple sample lines. The test provides rapid differential diagnosis, aiding clinical decision-making for patient management. Visibly bloody samples are contraindicated due to potential interference.
Clinical Evidence
Clinical performance was evaluated in a multi-site prospective study and retrospective frozen sample analysis. The study included 306 retrospective samples for Flu A and 303 for Flu B, representing diverse patient demographics (64% pediatric, 36% adult). Compared to individual predicate tests, the device demonstrated 100% sensitivity and 96% specificity for Influenza A, and 93% sensitivity and 97% specificity for Influenza B. Reproducibility studies across three sites showed 97% agreement. Analytical sensitivity (LOD) was established using inactivated viral strains. No clinical data regarding patient outcomes was provided; performance is based on diagnostic accuracy against predicate devices and viral culture.
Technological Characteristics
Lateral flow immunochromatographic membrane assay. Components: monoclonal antibodies, membrane support, cardboard hinged test device. Sample preparation: elution solution, saline, or transport media. Visual interpretation of colored lines. No electronic components, software, or external energy source required.
Indications for Use
Indicated for the qualitative detection of influenza A and B nucleoprotein antigens in nasopharyngeal swab and nasal wash/aspirate specimens to aid in the rapid differential diagnosis of influenza A and B viral infections in symptomatic patients. Negative results should be confirmed by culture.
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.
Predicate Devices
- FLU OIA A/B Test Kit (K021469)
