During a press conference on the Covid-19 epidemic on February 4, the Minister of Health Olivier Véran announced that saliva tests to detect the coronavirus would be deployed in schools and universities after the holidays winter. The first affected by this measure are the pupils of zone A, who returned to school on February 22 after two weeks of vacation. This zone brings together the academies of Poitiers, Lyon, Grenoble, Limoges, Dijon, Clermont-Ferrand, Bordeaux and Besançon.
These saliva tests, which are less painful, invasive and unpleasant than PCR tests, will also arrive in schools and universities in zone B and C when they return from vacation. The government has indicated that between 50,000 and 80,000 saliva tests will be carried out in these establishments "from this week", to reach 200,000 tests per week. This screening campaign in schools would make it possible to better assess the circulation of the virus in the school environment and to "break the chains of contamination".
How do saliva tests work?
Saliva tests are not a substitute for PCR tests. But they have several advantages, since they facilitate sampling, reduce the risk of contamination of healthcare workers and provide a less unpleasant test for patients.
But how do they work? To perform a saliva test, "You just need to take saliva, one of the main vectors of the virus, and place it with the reagents at 65 ° C for 30 minutes. The nursing staff can then read the result with the naked eye. of the reference test method which requires several hours of laboratory processing and requires significant equipment and reagents ", explains the National Center for Scientific Research (CNRS).
Covid-19: how will the saliva tests deployed in schools go on Monday?
Students are not required to perform these saliva tests. They will be carried out on a voluntary basis. "All the nasopharyngeal tests were not carried out because a lot of students and a lot of adults were not willing to do it because it is a little painful and complicated (…) With the saliva tests, we think that almost everyone will agree to be tested ", told BFMTV the Minister of National Education, Jean-Michel Blanquer.
Sampling kits will be distributed to schools. In each kit, students will find a tube they can spit into. The saliva of children under six can be collected with a pipette if it is difficult for them to spit up. "The sample must be taken 30 minutes after the last drink, food, cigarette / e-cigarette, tooth brushing or oral rinsing. And the sample collected must be stored in a dry and sterile bottle at room temperature ", specifies the Haute Autorité de Santé (HAS).
Will the results of saliva tests carried out in schools be delivered quickly?
Saliva tests done in schools and universities will not be rapid tests. "Only the sampling technique changes in this case", specified the Minister of Health, on February 4. "However, the examination then continues in the laboratory in the same way as for the tests that you know", he stressed. Samples must be returned to the laboratory within five hours of collection.
The results of these tests will not be delivered in 40 minutes, unlike those of rapid saliva tests. "It would be great if we could have saliva tests that give you a result in a few minutes, but at this stage, the studies (…) are not in favor of (their) use, because the sensitivity of the tests that exist today hui is too weak ", Olivier Véran added. The results will be communicated within twelve hours of performing the saliva test.
If the child's test is positive, he or she will need to do a screening test to detect the different variants of the coronavirus. The student will also have to notify his institution and not attend school. National protocol states that a class must be closed in kindergarten, if a child is a carrier of Covid-19, and in elementary school, if three students test positive for the virus.
Saliva tests authorized for asymptomatic people
In a notice published on February 11, 2021, the HAS gave the green light to extend the use of saliva tests to asymptomatic people. "The major advantage of these saliva tests is that they are completely non-invasive tests, therefore more easily accepted by people and especially young children. We don't need to use a swab to get to the back of the nose. It will be enough simply to spit in a tube or, for the little ones, to go directly under the tongue to look for the salivary volume ", explained Cédric Carbonneil, the head of the Service for the evaluation of professional acts at HAS to our colleagues from France Info.
These saliva tests can therefore be carried out as a second line in people with contact cases who cannot have nasopharyngeal swabs. They will also be used in large-scale screening campaigns in schools, universities, nursing homes and health establishments.
Saliva tests: they can be done from home
In its opinion, the HAS also specified that saliva tests can now be performed from home. To do this, the patient must go to a medical biology laboratory or a screening center in order to recover the self-collection material. Sure France Info, Cédric Carbonneil detailed its content: "the tube, the small wipe that will allow you to decontaminate the outside of the tube once you have taken the sample and then the small envelope to put the tube in so that you can then bring it back to the laboratory. "
"In the event of self-sampling, it is essential that the patient has received clear information on the conditions for its performance – and if necessary, its conservation ", can we read in the HAS document. The sample must be taken to the medical laboratory for analysis within 24 hours. The results are revealed three to four hours after the deposit of the sample as for the nasopharyngeal RT-PCR tests.
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