Description
A rapid chromatographic immunoassay for the qualitative detection of influenza A and B antigens in nasal swab specimens, it is used as an aid in the diagnosis of influenza A and B viral infections. The test is not automated. For self-diagnosis, professional use in the laboratory. For in vitro diagnostic use only.
Influenza (commonly known as the flu) is a highly contagious acute viral infection of the respiratory tract. The virus is transmitted when a susceptible individual comes into contact with respiratory aerosols or fomites from an infected individual.1 Flu epidemics occur annually during the autumn and winter months. Type A viruses are typically more prevalent than type B viruses and are associated with more severe flu epidemics, while type B infections are usually milder. Screen® Test Influenza A+B is a qualitative lateral flow immunoassay for the detection of influenza A and B virus antigens in human nasal or nasopharyngeal swab specimens. When the sample is added to the well, the extracted sample reacts with influenza A and/or influenza B antibodies that are coated on the particles, forming a mixture. The mixture migrates upward along the membrane and reacts with influenza A and/or influenza B antibodies present on the membrane, generating one or two colored lines in the test regions. The presence of this colored line in one or both test regions indicates a positive result, while its absence indicates a negative result. As a procedural control, a colored line will always appear in the control line region, indicating that the correct volume of sample has been added and that membrane wicking has occurred.

Sample Collection
Wash and dry your hands thoroughly.
Remove the sterile swab from the packaging.
Do not touch the soft tip of the swab.
- Nasal swab sample:
1. insert the swab into one nostril (approx. 2 cm deep);
2. rotate the swab slowly 5-10 times, rubbing it against the nasal wall.
Note: This procedure may cause discomfort. Do not insert the swab deeper if you experience strong resistance or pain. In case of damaged or bleeding nasal mucosa, nasal swab collection is not recommended. If swabbing others, wear a mask. In children, it may not be necessary to insert the swab as deeply into the nostril. In very young children, another person's help may be needed to hold the child's head still during swabbing.
3. Remove the swab and repeat the collection in the other nostril using the same swab.
NOTE 1 (For untrained users): The test should be performed immediately after sample collection.
NOTE 2 (For professionals): If the collected swab sample is not analyzed immediately, it should be stored in a dry, sterile, and tightly sealed plastic tube. Under dry and sterile conditions, the collected swab sample is stable for 8 hours at room temperature (15-30 °C), for 24 hours at 2-8 °C, and for 12 months at -20 °C and -70 °C. The sample can be frozen/thawed up to 3 times.

Instructions for Use
Allow the test cassette and swab to reach room temperature (15-30 °C) before performing the test.
1. Remove the cap from the buffer tube and insert the tube into the dashed circle on the packaging or into a tube rack.
2. Immediately insert the collected swab sample into the tube with the buffer.
3. Press the swab head against the inside of the tube and rotate the swab for 10-15 seconds.
4. Remove the swab by pressing the swab head against the inside of the tube to release as much liquid as possible from the swab.
Note 1: Dispose of the swab in accordance with local regulations.
Note 2: The test should be performed immediately after sample treatment with the buffer. Note 3: (For healthcare professionals only): The extracted sample is stable for 8 hours at room temperature, for 48 hours at 2-8 °C, and for 12 months at -20 °C and -70 °C. The extracted sample can be frozen/thawed up to 3 times.
5. Place the cap back on the tube.
6. Remove the test cassette from the foil pouch and place it on a flat, level surface. Invert the tube and add 3 drops of solution to the sample well (S) of the test cassette.
Note: If a drop of added solution contains air bubbles, add another drop to the well.
7. Start a timer and read the result 10 minutes after adding the sample. Do not interpret the result after 20 minutes.
Note: Do not touch or move the test cassette during the waiting time.
8. After completion, dispose of all used components in accordance with local regulations.

Reading Results
POSITIVE (+)
POSITIVE Influenza A:* two colored lines appear in the window. One colored line should be in the control zone (C) and the other in the influenza A zone (A).
POSITIVE Influenza B:* two colored lines appear in the window. One colored line should be in the control zone (C) and the other in the influenza B zone (B).
POSITIVE Influenza A and Influenza B:* three colored lines appear in the window.
One colored line should be in the control zone (C) and two colored lines should be in the influenza A zone (A) and influenza B zone (B) respectively.
This indicates that you may be in a stage of Influenza A and/or Influenza B infection and should consult your doctor.
*NOTE: The intensity of the color of the line in the A/B region will vary depending on the amount of Influenza A/Influenza B virus present in the sample.
Therefore, any shade of a colored line in the regions indicates a positive result.
NEGATIVE (-)
If only one colored line appears in the control line region (C) and no colored line appears in the influenza A region (A) and influenza B region (B), the result is negative.
This indicates that no influenza A/influenza B virus antigens were detected in the sample or their quantity is too low to be detected.
INVALID
If the line in the control zone (C) does not appear, the result is invalid. The most likely causes are incorrect testing procedures or deterioration of reagents. Review testing procedures and repeat the test with a new kit.

Warnings
1. This kit is for in vitro diagnostic use only. Do not use after the expiration date.
2. Do not ingest the swab and other items in the package.
3. Do not eat, drink, or smoke in the area where samples or kits are handled.
4. Store the kit in a dry place at a temperature between 2 and 30 °C (36-86 °F). Do not use the kit if the contents or packaging are damaged.
5. Use the test only once and strictly follow the testing procedures. Do not disassemble the test cassette or touch the reading window of the test cassette.
6. Keep the kit out of reach of children. Testing on children should be performed by an adult.
7. The used kit should be disposed of in accordance with local regulations.
8. Wash your hands thoroughly before and after handling.
9. If the buffer solution comes into contact with skin or eyes, rinse with plenty of water.
10. Any serious incident that has occurred in relation to the device should be reported to the manufacturer and the competent authority.
11. The components provided in the kit are approved for use in the Screen Test Influenza A+B. Do not use any components in other commercial kits.

Limitations
1. The test should be used for the detection of influenza A and influenza B viruses in nasal swab samples. This qualitative test cannot determine either the quantitative value or the rate of increase in the concentration of influenza A and influenza B viruses.
2. A false negative result may be obtained if the concentration of influenza A and influenza B viruses present in the sample is not adequate or is below the detectable level of the test.
3. The accuracy of the test depends on the quality of the collected swab sample.
False negative results may result from improper sample collection or storage.
4. Excess blood or mucus on the collected swab sample can interfere with test performance and produce a false positive result.
Screen Test Influenza A+B provides preliminary results that cannot be used as the sole basis for treatment or other therapeutic decisions. As with all diagnostic tests, a confirmed diagnosis should only be made after evaluating other clinical information available to the physician.

Storage
1. Store the kit at a temperature between 2 and 30 °C. Do not freeze.
2. Keep the kit away from sunlight, humidity, and heat.
3. Do not use the kit beyond the expiration date.
4. Open the pouch only shortly before testing.
5. Use the test cassette within one hour of removing it from the foil pouch.