SARS-CoV-2 & Influenza Antigen Combo Rapid Test Kit (A254397)

The SARS-CoV-2 & Influenza Antigen Combo Rapid Test Kit is an in vitro immunochromatography assay for the qualitative and differential detection of nucleocapsid (N) protein antigens from influenza A (including the H1N1 subtype), Influenza B, and SARS-CoV-2 viruses in human oropharyngeal swab, nasal swab and nasopharyngeal swab specimens. It is intended to aid in the rapid diagnosis of these three viral infections in patients, which present similar respiratory symptoms and so are difficult to diagnose from clinical evaluation alone. All three viruses have epidemic potential, so proper diagnosis is important for treating patients and controlling the diseases.

The test consists of two parallel immunochromatographic membrane assays. When the sample is added to the well, the solution migrates up the membrane due to the capillary effect. In the SARS-CoV-2 test, if there are SARS-CoV-2 N protein antigens present in the sample, then these will be bound by monoclonal anti-SARS-CoV-2 N protein antibodies conjugated to colloidal gold, which are present in the test strip. These migrate with the solution to the test (T) line position on the membrane, which is coated with immobilized anti-SARS-CoV-2 N protein antibodies. These also bind the antigens, such that conjugated antibody-SARS-CoV-2 N protein-capture antibody complexes accumulate at the T line, and a red line is formed. In the Influenza test strip, the same principle is followed. If there are Influenza A N protein antigens present in the sample, these are bound by colloidal gold conjugated anti-Influenza A N protein antibodies, and are captured by anti-influenza A N protein antibodies coated to the test strip to form a line at the A position; Influenza B antigens present in the sample and monoclonal anti-Influenza B N protein antibodies similarly form a line at the B position. Therefore, the presence of lines at the T, A, and B positions ten minutes after adding the sample can be used in the positive diagnosis of SARS-CoV-2, Influenza A, and Influenza B infections respectively, whilst the absence of each line indicates a negative result.

On both strips, to serve as a procedural control, a red line will always appear at the control (C) position. If this C line is absent after ten minutes, the result is invalid, and the test should be repeated using a new cassette.

SARS-CoV-2 & Influenza Antigen Combo Rapid Test Kit comes in packs of 25 tests and contains:

• 25 x Test Cassette.
• 25 x Swab
• 25 x Sample Treatment Solution in Tube
• 25 x Tube Cap

Clinical performance:

The performance of the SARS-CoV-2 Antigen Rapid test was established using 341 clinical swabs, and results were compared to RT-PCR assays results (109 positive, 232 negative). The kit displayed sensitivity of 96.3% (105/109), and specificity of 99.6% (231/232). Additionally, test results from separate oropharyngeal swabs, nasal swabs, and nasopharyngeal swabs were compared from 50 subjects. The consistent detection rate between swab types is 100%.

The performance of the Influenza A and B antigen rapid test was established by comparing the results to those from a virus isolation culture test. The clinical sensitivity for the Influenza A test is 89.5%, and the specificity is 98.0%. The clinical sensitivity of the Influenza B test is 97.2%, and the specificity is 99.5%. Additionally, test results from separate oropharyngeal swabs, nasal swabs, and nasopharyngeal swabs were compared from 50 subjects. The consistent detection rate between swab types is 100%. Please read the product data sheet for additional and more detailed performance statistics.

Limit of Detection:

The LOD was determined as the lowest virus concentration that was detected at least 95% of the time (i.e., the concentration at which at least 19 out of 20 replicates tested positive, expressed as 50% Tissue Culture Infectious Dose per milliliter, TCID₅₀/ml). The SARS-CoV-2 Antigen Rapid Test LOD concentration was 5×10⁴ TCID₅₀/ml.

Hook effect:

The Hook effect is an immunological phenomenon in which the ability of antibodies to form immune complexes is sometimes impaired when concentrations of an antibody or an antigen are very high, resulting in false negatives or inaccurately low results. Within the titer range of clinically positive samples, the SARS-CoV-2 Antigen Rapid test result does not show a Hook effect. The Influenza A antigen test does not show any Hook effect when the titer was not higher than 5×10⁸ TCID₅₀/L. The Influenza B antigen test does not show any Hook effect when the titer was not higher than 5×10⁵ TCID₅₀/L.

Cross-reactivity:

The SARS-CoV-2 Antigen test showed no cross-reactivity with the following (see data sheet for concentrations tested): Staphylococcus aureus, Streptococcus pneumoniae, Measles virus, Mumps virus, Adenovirus type 3, Mycoplasma pneumoniae, Parainfluenza virus type 2, Metapneumovirus, Coronavirus OC43, Coronavirus 229E, Bacillus parapertussis, Type B influenza virus Victoria line, Type B influenza virus Y line, Type A influenza virus H1N1, Type A influenza virus H3N2, Avian influenza virus H7N9, Avian influenza virus H5N1, Epstein barr virus, Enterovirus CA16, and Rhinovirus.

The Influenza A and B Antigen rapid tests showed no cross-reaction with the following (see data sheet for concentrations tested): Influenza virus C, Parainfluenza virus, Adenovirus, Human Coronavirus OC43, Respiratory Syncytial virus, Herpes Simplex virus, Mumps virus, Rhinovirus, Varicella-Zoster virus, Respiratory Chlamydia, Mycoplasma, Tuberculosis, Pertussis, Candida albicans, Diphtheria, Haemophilus influenzae, Legionella pneumonia, Mycobacterium tuberculosis, Staphylococcus aureus, E. coli, Pseudomonas aeruginosa, Streptococcus. The Influenza A test does not show cross-reactivity with Influenza B, and the Influenza B test does not show cross-reactivity with Influenza A.

Interfering substances:

The SARS-CoV-2 Antigen rapid test showed no interference from the following substances (see data sheet for concentrations tested): Mucin, Whole Blood, Biotin, Histamine dihydrochloride, IFN-a, Zanamivir, Ribavirin, Oseltamivir, Paramivir, Lopinavir, Ritonavir, Arbidol, Levofloxacin, Azithromycin, Ceftriaxone, Meropenem, Tobramycin, Antinuclear antibody (ANA), Anti-mitochondrial antibody (AMA), or Mouse IgG.

The Influenza Antigen Rapid Test showed no interference from the following substances (see data sheet for concentrations tested): Whole Blood, Mucin, pus, Aspirin, N-acetaminophen, Ibuprofen, Ribavirin, Oseltamivir, Cephalexin, Gentamicin, Tetracycline, Chloramphenicol, Moxifloxacin, Hydrocortisone, Artificial Insulin, and other drugs.

Warnings:

• For in vitro diagnostic use only.
• The test device should remain in the sealed pouch until use.
• Do not use the kit past its expiration date.
• Swabs, tubes, and test devices are single use only.
• The extraction buffer contains a solution with a preservative (0.05% Proclin 300). If the solution comes into contact with the skin or eyes, flush with ample volumes of water.
• Do not interchange or mix components from different kit lots.
• When collecting an oropharyngeal, nasal, or nasopharyngeal swab sample, only use the suitable swabs supplied in the kit.
• Wear appropriate personal protective equipment and gloves when running each test and handling patient specimens. Change gloves between handling of specimens suspected of COVID-19.
• Specimens must be processed as indicated in the SPECIMEN COLLECTION and SAMPLE PREPARATION PROCEDURE sections of the product insert. Failure to follow the instructions for use can result in inaccurate results.
• To obtain accurate results, do not use visually bloody or overly viscous samples.
• Proper laboratory safety techniques should be followed at all times when working with SARS-CoV-2 patient samples. Patient swabs, used Test Strips, and used extraction buffer vials may be potentially infectious. Proper handling and disposal methods should be established by the laboratory in accordance with local regulatory requirements.
• Humidity and temperature can adversely affect results.