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Express test for influenza
Last reviewed: 19.10.2021
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Children, the elderly, pregnant women constitute the main contingent for which the flu is particularly dangerous. In order to carry out home diagnostics in time and protect relatives from infection, it is advisable to have a rapid test for flu in your home medicine chest. Early diagnosis allows you to take timely measures to successfully treat a patient and prevent infection of his close environment.
With the help of a test at home, it is easy to diagnose whether the symptoms are fairly common signs of influenza. The accuracy of the result is about 70%. This check can be carried out by any person, adult enough to read and understand the instructions attached to the express test. The main thing is to test the patient in the first two or three days from the appearance of the first symptoms, at this time the least probability of false positive and false negative results is observed.
[Indications for use
Symptoms that test: hyperthermia (39 ℃ and above), chills, headache and muscle pain, weakness, nasal congestion, sore throat, cough, lack of appetite, diarrhea and vomiting (more often in children).
Form of issue
Completeness may differ slightly in products of different brands. An approximate list of the composition of the test: a test cassette, a reagent bottle, a disposable pipette, a sterile cotton swab for sampling biomaterial. All this is packed in a cardboard box with a nested instruction.
The names of rapid tests for the definition of influenza
Basically, rapid tests for the flu, which can be purchased at pharmacies, are an immunochromatographic analysis of nasal secretions, revealing the antigens of diseases of types A and B, including the so-called "swine" influenza, belonging to type A.
In the Ukrainian pharmacies the most popular is the rapid test CITO TEST INFLUENZA A + B company Pharmasko.
In online stores, you can buy tests of Russian production RED FLU A and B, manufactured by RED Ltd., and SALUTA's ICHECK Test Kit, FLU A & B-30 test by Chinese manufacturer Guangzhou Vondfo Biotech.
How is the rapid test for influenza done?
It is recommended to test a patient for viruses on the second-third day, when the activity of their isolation reaches its peak.
The biological material for testing is a nasal secretion smear (for other isolates, the test is calculated). His fence is made as follows: a cotton swab with a sterile swab on the end is released from the package and, having thrown back his head, is introduced into one nostril. Rotational movement is carried out with a stick along the walls of the nose, trying to collect more of the cells on the swab, and not just the liquid secret. Remove the stick from the nose and place the sample of excreta in the vial, previously screwing the lid off of it. Vigorously mix the contents of the vial with a swab at least ten times. Then squeeze the tampon with the walls of the plastic vial as conscientiously as possible, discard it and turn the cap on the vial. Unpack the test cassette from the package and place it on a horizontal flat surface with a window facing up. Shake well the sample vial, cut off the tip from the dropper cap and drop four droplets of contents onto the oval window for the biomaterial on the side of the test cassette. Wait exactly 10 minutes and interpret the result (lines that appear after a ten-minute interval are not taken into account!). The result is estimated by the color lines that appeared in the rectangular central window.
The appearance of one green line in this window indicates that there are no antigens to the influenza viruses and the test was carried out correctly - a negative result.
Next to the green test line (control), the second one appeared - red (the color can be of a different shade from saturated to pink). A positive result, which speaks of infection with virus A.
Near the control line appeared a blue (blue) color - a positive result, indicating the infection with the virus B.
There are cases of false negative results if the concentration of antigens is below the level of sensitivity of the test or insufficient amount of biomaterial.
If the green control line does not appear, the test result is considered invalid, even if there is a red or blue strip. In this case, the test is recommended to be repeated.
The rapid test for influenza is considered as a preliminary diagnosis, the final diagnosis is made by the doctor on the basis of examination of the patient and laboratory tests.
The test remains sensitive until the end of the period indicated on the package. After this date, its results are invalid. Store it in original sealed packaging, which is opened immediately before the study. Storage temperature should be maintained between 2 and 30 ℃.