To test. To track. Since the beginning of the pandemic from Covid-19 these two passwords resound in the ears of those who have to follow the course of the infection. Only by recognizing early on people who may have contracted the infection, and perhaps do not show particular symptoms, can one try to better limit the outbreaks and make sure that the third T, or the treatment, has the desired effects.
In order to further increase the potential for identifying possible infections, now they are about to arrive saliva tests. They could be very useful in terms of screening, for example in schools, but they cannot replace the normal molecular tests from nasopharyngeal swabs, necessary for diagnosis.
How to make
Experiments on this diagnostic modality are certainly offering interesting results. Suffice it to mention in this sense a study conducted by the University of Singapore and appeared in Scientific Reports, which showed on a population collected in a dormitory and in a care center for non-seriously ill patients that these tests are able to collect the positivity to the virus. sars-CoV-2 of subjects with efficacy.
Above all, their sensitivity would be particularly useful, given that they were also able to identify subjects who did not present any symptoms and people who had mild disorders and in any case with a low viral load, or with “few” viruses present in the body. Obviously, in the face of these data, we must not think that these are tests that allow a diagnosis with certainty. For this reason they could be considered as the so-called “fast” or antigenic swabs, very useful for screening but which still require confirmation if diagnostic certainty with molecular tests is necessary.
Having made these necessary clarifications on the tests that should arrive, it must be said that the “taking” of the sample is simpler compared to the swab that is carried out high in the nasal cavities and deep in the mouth. This is why we speak of these means as potential screening controls, perhaps on a sample basis, especially in large community environments, such as for example the schools, even a child, in fact, can be subjected to the examination without particular difficulties.
Generally, we proceed by delivering a small stick that has a piece of cotton at the end (but you can also proceed with a wad even alone, to keep in your mouth until it fills with the saliva present). Once this phase is finished, you can then move on to take the sample and place it in a sterile test tube or in a small plastic container that is sent to the laboratory for subsequent analysis.
But be careful: for the possible spread over large numbers of this screening strategy, it must also exist the necessary organization. In fact, it should be remembered that saliva can naturally be very “variable” and therefore in some cases it may not be optimal for the equipment currently used to search for the “signs” of the virus. Furthermore, it is necessary to think of a laboratory very close to the points where the screening is carried out in order not to lose something in terms of sensitivity of the examination.
However, one certainty remains: like the so-called antigenic or rapid swab, salivary tests can also identify the presence of parts of the Sars-CoV-2 virus and therefore inform about the presence or absence of the infection. Finally, there is another aspect that should not be underestimated: the saliva test could be useful if the doctor considers it, as an alternative to the search for antibodies, to see the defensive reactions after an infection or after vaccination.