The University of Algarve (UAlg) is studying the use of saliva in the collection of samples to detect the new coronavirus, a less invasive method compared to the classic test of the nose mucosa, an investigator told Lusa.
According to Clévio Nóbrega, from the UAlg Biomedicine Research Center (CBMR), the objective is to try to “validate other methods” for the collection of samples, especially for “children and people with some pathologies”, since the current PCR method is "Very invasive".
Speaking to Lusa, the official said that the investigation sought to compare the efficacy of saliva collection with nasopharyngeal and subsequent analysis by PCR, a process based on molecular biology and which allows an increase in the amount of genetic material to detect the new coronavirus (SARS- Cov-2).
In collaboration with the Centro Hospitalar Universitário do Algarve (CHUA), the researchers obtained samples from hospitalized patients through three types of collection: the “classic” nasopharyngeal (with the collection of secretions from the nose), through the saliva and oropharynx, obtained at the bottom throat.
According to Clévio Nóbrega, “the same results” were obtained, and it was possible to detect by saliva “the same level” as the “classic” sample, which means that, in some cases, “this type of collection ”.
The use of this method is still “not possible”, because “authorization is required” from the National Institute of Health Doutor Ricardo Jorge Instituto Ricardo Jorge (INSA), where the data were sent.
Clévio Nóbrega recognizes, however, that it is understandable that the focus is on “continuing mass testing and not so much on optimization” of collection methods.
Meanwhile, the researchers will continue to carry out “additional tests” to confirm that the results are “in fact reliable”, something that has been “confirmed”, he stressed.
In addition to the use of saliva, that UAlg center is also following another line of research that consists of seeking to remove a step from the whole process, making it faster and less expensive.
The usual testing process begins with the collection of the sample with the swab, then with the extraction of the RNA (ribonucleic acid) from the SARS-Cov-2 virus, followed by the molecular PCR (Polymerase Chain Reaction) test.
The researchers are trying to remove the step of extracting the genetic material from the virus, moving directly from the collection to the PCR technique, “avoiding a step”, which would make the process “cheaper and much faster”, he defended.
However, the results “have not yet been positive”, lamented Clévio Nóbrega, with the researchers achieving “some amplification in the PCR and some detection of the virus”, but “very low”, compared with the results obtained with the method currently used.
“These are not sufficiently reliable results. We continue to test and optimize. Unfortunately, we have had a pandemic for some time and our main objective is to optimize and that is what we are still working on ”, he concluded.