The antigen test is used to detect an active infection as it identifies the presence of virus proteins. It is not as sensitive as PCR and is valid only for the day it is done. The ideal is to do it in the first 7 days after infection (in the first 5 if you have symptoms), as this is the time when the viral load is at its highest point. Therefore, it is not advisable to take an antigen as soon as you know that we have been in contact with someone infected , surely there will not be time for the infection to become active.
Get your antigen test only and exclusively at the pharmacy . Self-diagnostic antigen tests must have the CE marking on their label followed by the 4 digits of the notified body that has evaluated it. Its price ranges from € 8, if you buy one, to € 40 if you opt for the five-unit pack.
Aspects to take into account with the antigen test
- Before getting down to work, carefully read the manufacturer’s instructions for use. To prevent the sample from degrading, test immediately after obtaining it.
- The most reliable result is obtained when there are symptoms.
- If it is negative for covid, it indicates that either there is no virus at that precise moment or that if the person is infected, their viral load is low (reduced number of viruses in the sample), which is something that occurs in the first days of infection or in the last. It must be borne in mind that the virus can be transmitted even a day later if the viral load rises, in case of having undetected covid.
- Even if the test was negative, do not relax the protection measures: wear a mask, try to maintain interpersonal distance and maintain hand hygiene. Negative results can create a false sense of security.
- If the result is positive, you should isolate yourself and report it to the health center. Of course, you must inform your direct contacts.
Steps to take the antigen test from the pharmacy
- Prepare the reagent. The first thing to do is wash your hands. The next thing will be to place the tube vertically (in the box itself there is a hole to place it) and pour the reagent liquid into it.
- Take the nose sample. Now open the packaging of the swab (rod) being careful not to touch the cotton ball. Insert the swab into your nose about an inch. You have to put it in both nostrils and give it about three or four turns, touching the walls of the nostril with the cotton. About 10-15 seconds per nostril is sufficient. Once the sample is taken, we put the swab in the tube with the reagent and let it soak for a minute so that it is well impregnated.
- Pour three drops of the mixture into the S. The next step is to remove the swab from the tube and discard it wrapped. Now cover the tube with the accompanying lid that turns it into a dropper. Take out the developer card, put it on a flat surface, and pour three drops of this mixture into the hole with an S. Wait about 15 to 20 minutes to get the result.
- The result. To make sure that the test works and the reagent is in good condition, a mark should appear next to the letter C. If after the time indicated by the manufacturer it does not appear, the test will be negative. If, on the contrary, the mark appears next to the T, it will be positive. In the latter case, as we have mentioned, you must notify your health center and your direct contacts. You may also need to have a PCR done.