University of Algarve study finds saliva tests just as reliable as nasal swabs

The University of the Algarve (UAlg) is studying the use of saliva as an effective method for detecting the coronavirus, with findings so far showing that saliva tests are just as reliable as the widely-used nasal swabs.

Speaking to Lusa news agency, researcher Clévio Nóbrega from the university’s Biomedicine Research Centre said the goal is to “validate other methods” of testing, especially for children and people with medical conditions, as the PCR test which resorts to a nasal swab is “very invasive”.

Researchers have collected samples from patients hospitalised at the region’s public hospitals using three methods: nasal swab, saliva and oropharyngeal (from the back of the throat).

Said Nóbrega, the same results were obtained, with saliva tests detecting the same levels of the virus as nasal swabs.

Their findings have been sent to the National Institute of Health Doutor Ricardo Jorge, which will have to give saliva tests the ‘seal of approval’ as viable alternatives before they can start being used widely.

However, the researcher acknowledges that the focus at the moment is on “mass testing” as opposed to “optimising the sample collection” process.

Meanwhile, researchers will continue to carry out tests to confirm if the findings are “reliable”. According to Clévio Nóbrega, they have been so far.

Apart from the saliva test, researchers are also studying whether they can “remove a step” from the whole testing process, making it quicker and less expensive.

The process begins with the collection of a sample, followed by the extraction of ribonucleic acid (RNA) from the SARS-CoV-2 virus, followed by the PCR test.

Researchers are trying to do away with the RNA extraction, but so far with little luck. Their findings have proven that the tests have remained much more reliable with the second step of the process.

Still, research will continue. “Unfortunately, this pandemic is here to stay and our goal is still to try and optimise the process,” Nóbrega concluded.