Źródło: FDA
Data ostatniej weryfikacji: 2025-07-15
Opakowanie:
Ulotki Wondfo One Step Strep A Swab Angina Test dla opakowania 1 sztuka.
Źródło: FDA
Data ostatniej weryfikacji: 2025-07-15
To obtain substantial equivalence for the Wondfo® One Step Strep A Swab Test C. Measurand: Group A Streptococcal antigen D. Type of Test: Lateral Flow Immunochromatographic assay E. Applicant: Guangzhou Wondfo Biotech Co., Ltd.
1. Regulation section:
2. Classification: Class I
3. Product code: GTY - Antigens, All Groups, Streptococcus spp.
83 Microbiology H. Intended Use:
1. Intended Use(s): The Wondfo® Strep A Rapid Test is a chromatographic immunoassay for the qualitative detection of Strep A antigen from throat swab specimens from symptomatic patients to aid in the diagnosis of Group A Streptococcal infection. All negative test results should be confirmed by bacterial culture because negative results do not preclude Group A Strep infection and should not be used as the sole basis for treatment. This test is intended for professional and laboratory use, only.
2. Indication(s) for Use: The Wondfo® Strep A Rapid Test is a chromatographic immunoassay for the qualitative detection of Strep A antigen from throat swab specimens from symptomatic patients to aid in the diagnosis of Group A Streptococcal infection. All negative test results should be confirmed by bacterial culture because negative results do not preclude Group A Strep infection and should not be used as the sole basis for treatment. This test is intended for professional and laboratory use, only.
For in vitro diagnostic use only
4. Special instrument requirements:
None I. Device Description: The Wondfo® One Step Strep A Swab Test is a qualitative, lateral flow immunoassay for the detection of Strep A carbohydrate antigen directly from a throat swab sample. To perform the test, Reagent 1 (R1) is added to the extraction tube which is coated with a mixture of conjugate antibodies and a lytic enzyme extraction reagent. The lytic enzyme is mixed with colloidal gold conjugated to rabbit anti-Strep A and a second colloidal gold control conjugate antibody. The reagents are dried onto the bottom of an extraction tube forming a red spot.
The test strip is immediately placed in the extracted sample. If Group A Streptococcus is present in the sample, it will react with the anti-Strep A antibody conjugated to the gold particle. The complex will then be bound by the anti-Strep A capture antibody and a visible red test line will appear, indicating a positive result. To serve as an onboard procedural control, the blue line observed at the control site prior to running the assay will turn red, indicating that the test has been performed properly. If Strep A antigen is not present, or present at very low levels, only a red control line will appear. If the red control line does not appear, or remains blue, the test result is invalid.
1. Predicate device name(s): Status First™ Strep A
2. Predicate 510(k) number(s): K040708
Similarities Item Device (K133343) Predicate (K040708) Intended Use For the qualitative detection of group A streptococcal antigen directly from throat swabs
Similarities Item Device (K133343) Predicate (K040708)
Differences Item Device (K133343) Predicate (K040708) Control Antibodies Goat polyclonal anti-Strep A Rabbit polyclonal anti-Strep A Clinical Sensitivity 95 %: 95% CI (88-98%) 96.2%: 95% CI (95-98.9%) Clinical Specificity 98%: 95% CI (96-99%) 98.7%: 95% CI (98-100%) Wait Time for Results Read 10 minutes 5 minutes Extraction Method Extraction performed in a test tube and transferred to test device
Not applicable L. Test Principle: The Wondfo® One Step Strep A Test utilizes double antibodies sandwich immunoassay for the detection of Group A Streptococcal antigen. The test device consists of plastic housing containing a test strip which has been pre-coated with rabbit anti-Strep A antibody on the test band region and goat anti-rabbit antibody on the control band region. When the device is immersed into the specimen, the specimen is absorbed into the device by capillary action, mixes with the antibody-dye conjugate, and flows across the pre-coated membrane.
This produces a colored Test band and indicates a positive result. When the group A streptococcal antigen levels are zero or below the target cut off, there is not a visible colored band in the Test region (T) of the device. This indicates a negative result. To serve as a procedure control, a colored line will appear at the Control region (C), if the test has been performed properly.
1. Analytical performance: a. Precision/Reproducibility:
The test panel consisted of a true negative sample (diluent only), a moderate positive sample (2.3×106 organisms /mL), a low positive cut-off sample (1.5×105organisms
The overall results were as follows:
Overall detection
The results suggest that there are no significant differences between different users, different sites and different lots in different days. Reproducibility studies appear acceptable.
Not applicable – This assay is qualitative.
Traceability:
Stability:
Additionally, all swabs were extracted and tested immediately at each time point. For the LoD swabs, three swabs per time point and temperature were evaluated in the assay. For blank swabs (no bacteria), three replicates were evaluated.
Stability results are acceptable.
Cross-Reactivity:
1 ×108 organisms per mL with the Wondfo One Step Strep A Swab Test, in order to investigate the analytical specificity (cross-reactivity) of Wondfo One Step Strep A Swab Test. Three laboratory assistants with relevant experience, who are blind to the samples, read the results per batch. Three lots of the assay were used in these studies.
Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, Streptococcus pneumoniae, Streptococcus sanguis, Arcanobacterium haemolyticum, Bordetella pertussis, Branhamella catarrhalis, Candida albicans, Corynebacterium diphtheriae, Enterococcus faecalis, Enterococcus faecium, Escherichia coli,
Neisseria meningitides, Neisseria mucosa, Neisseria sicca Neisseria subflava,
Rhinovirus
Interference:
Substance Concentration Tested
60 μg/mL
An additional study was performed to investigate the potential of Agar Interference on the performance of the Wondfo One Step Strep A Swab Test. In this study, a positive stock of inactivated Streptococcus pyogenes and a negative stock of Streptococcus agalactiae were grown on blood agar media plates, from three different manufacturers.
The swab was then run through the Rapid Strep A Test. The plates were then cultured for 48 hours. The same was done using the stock negative testing plates.
OTC Lozenges Sucrets Complete (Cool Citrus) 10%(vol/vol) Halls Cherry Mentholyptus 10%(vol/vol) Halls Plus Mentholyptus 10%(vol/vol) Cepacol Cherry Sore Throat 10%(vol/vol) OTC Throat Sprays Cepacol Dual Relief 20%(vol/vol) Chloraseptic Max 20%(vol/vol) OTC Cough Syrups Tylenol Cough and Sore Throat 10%(vol/vol)
Robitussin (Guaifenesin Syrup) 1%(vol/vol) Robitussin Nighttime Cough 10%(vol/vol) Children’s Dimetapp Cough Plus 10%(vol/vol) Children’s Dimetapp DM Elixir 10%(vol/vol) Active Ingredients
Guaifenesin (Guaiacol Glyceryl) 20mg/mL
Interference studies are acceptable.
In order to determine the assay cut-off concentration, a concentrated stock (2.3x107 organisms/mL) of inactivated Streptococcus pyogenes (ATCC #20159) was serially diluted in the solution of extraction reagents. Each dilution was tested by seven operators each with three batches of Wondfo One Step Strep A Swab Test. A total of
Levels (organisms /mL) 2.3x106 1.5x105 0.8x105 0.4x105 1x103
Negative # 0 1 5 11 18
The assay cut-off was determined to be 1.5 x 105 organisms/mL.
2. Comparison studies: a. Method comparison with predicate device:
Not applicable
The clinical performance of the Wondfo One Step Strep A Swab Test was established in a multicenter prospective clinical study in 2011 – 2012 at six geographically diverse sites. A total of 349 throat swabs were collected from patients exhibiting symptoms of pharyngitis.
Clinical Performance
Positive 96 4 100
Total 101 248 349
Specificity (244/248) = 98.4 %; 95 % CI = 95.9 – 99.4 % Clinical Performance Stratified By Age Age Sensitivity Sensitivity (95% CI) Specificity Specificity (95% CI) 0-5 84% 60%-96% 100% 87%-100% 5-21 97% 88%-99% 98% 93%-99% 21+ 100% 80%-100% 99% 92%-100%
c. Other clinical supportive data (when a. and b. are not applicable):
4. Clinical cut-off:
5. Expected values: Group A Streptococcus bacteria are responsible for about 19% of all upper respiratory tract infections. Infection is most prevalent in winter and early spring, with most cases arising in patients living in highly populated areas. In the multi-center clinical study conducted by Wondfo in 2011-2012, 28.9% (101/349) of the patients presenting with pharyngitis were found to be culture positive for Strep A.
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.