Published 22 November 2021 at 10.04
Home page. The most commonly used method of testing for covid-19 is an unpleasant PCR test through a nose selection sample taken with a cotton swab. But in a new study from Lund University, the researchers state that a painless saliva test can work just as well.
Like the article p & aring; Facebook
– Our results indicate that saliva-based rapid tests may be sufficient to diagnose covid-19 at an early stage of the infection, says Magnus Rasmussen, specialist in infectious disease medicine at Skåne University Hospital and professor at Lund University, in a mailing.
Today, there are several different test methods to identify an ongoing infection. The PCR tests used in healthcare are usually taken with swabs in the nasal cavity and this also applies to most commercially available antigen tests, a method that many find unpleasant.
Antigen testing is used as a complement to PCR testing when increased test capacity or rapid test results are required. And then there are saliva tests.
– Saliva-based tests are less unpleasant, simpler and easier to handle. You also do not need trained healthcare professionals to spit in a cup, says Magnus Rasmussen.
In the current study, published in Infection Ecology & amp; Epidemiology, the researchers compared RT-PCR tests with swabs from the nasal cavity and saliva samples they collected from 44 patients at Skåne University Hospital in Lund.
All 44 participants had confirmed covid-19, and had to clear their throat for the saliva test before spitting. The results showed that coronavirus can be detected in both saliva and nasal selection samples, but that the concentrations are slightly lower in saliva. The researchers also examined four different rapid antigen tests available on the market to see how well they find viruses in saliva samples.
All four antigen tests were found to be relatively sensitive in detecting the virus early in the infection because the virus concentration is higher then. Later during the infection, when the virus concentration is lower, the antigen tests did not prove to be sensitive enough.
– The advantage of a saliva-based rapid test is that you can easily take it yourself at home in peace and quiet. For many, it can make a big difference. If infection occurs in, for example, primary school, the younger unvaccinated students can be screened more quickly with a saliva-based rapid test. For children, it is important that sampling is simple and without discomfort, says Yang de Marinis, who is the first author of the study.
The researchers believe that rapid saliva tests are a good alternative to regular PCR testing and nose selection tests, and can also supplement these methods as screening needs increase.
– Before we can start using salivary antigen tests, we need to confirm that they work to identify covid-19 also in newly infected and previously vaccinated individuals. Such studies are ongoing with us and also in other places, says Magnus Rasmussen.