In addition to rapid and molecular swabs, swabs that can be purchased at home or salivary antigen tests can also be used to check for the presence of Covid-19 infection. There are two models on sale, in pharmacies and in some supermarkets: one nasopharyngeal and one salivary. They are not valid for obtaining the green pass, they are considered reliable but have an oscillating sensitivity.
Do-it-yourself tests against covid Let’s clarify, let’s see how they work. Do-it-yourself tests are, like rapid swabs made in pharmacies, antigenic: they are able to detect the coronavirus proteins present in the body, but do not signal the presence of antibodies or the genetic material of the infection. As mentioned, the do-it-yourself tests are not considered valid for obtaining the green pass. And this is because being performed by the person directly concerned, there is no control by another subject to verify that the result of the test is actually of the person presenting it. The nasopharyngeal model works essentially like the one done in the pharmacy, with the insertion of the swab deep into the nostrils to collect sufficient material to highlight the presence of the coronavirus. The swab is then placed in a test tube with reagent liquid, included in the packs for sale. Then you have to drop a few drops of the liquid on the tester, a plastic box similar to those used for pregnancy tests. If two dashes appear, it means that you are positive for the coronavirus. Salivary tests, on the other hand, investigate the presence of traces of Covid-19 directly from the saliva. Before making one, you don’t have to ingest anything for the previous ten minutes. The saliva is inserted into the test tube that is sold with the package. Once a sufficient amount of saliva has been collected, a reagent liquid is then added. Drops of saliva and reagent mixed are then placed on a tester, as for DIY nose tests. The results will arrive in about ten minutes. Both of these types of DIY tests are believed to be reliable, but their sensitivity fluctuates. The ECDC (European Center for Disease Prevention and Control), for example, reports that, in the pediatric range, the results are not always accurate, with an accuracy between 53 and 73%. It is advisable, in the event of symptoms but with a negative result of DIY tests, to also undergo a molecular swab or in any case to consult your doctor. Even if the tests are positive, you must then undergo molecular tests in any case and, while waiting for the results, observe the quarantine as if you were sure to be positive. In the “Interim Strategic Indications Report for the Prevention and Control of SARS-CoV-2 Infections in Schools”, the Higher Institute of Health indicated salivary tests as a tool to protect the conduct of face-to-face lessons. The tests to which the document refers, however, are the molecular salivaries and not the antigenic ones.
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