Health professionals from the Atenció Primària Metropolitana Nord of the Institut Català de la Salut (ICS) have detected in a study that rapid antigen tests (TAR) carried out from nasal samples give "better performance" than those carried out with oral samples (of saliva) to detect positive cases of Covid-19.
To prepare the work, published in ‘MedRxiv’, they have analyzed samples from 300 users –95% of whom had symptoms compatible with Covid-19– from primary care emergency centers (Cuap) and centralized points where carry out tests to detect the disease, the ICS reports in a statement this Thursday.
The researchers collected both types of samples for all the people participating in the study, on the one hand, they underwent an ART with the nasal sample and, on the other, an ART was made with the saliva sample.
In the event that the results of the two tests do not coincide, they have asked the person if a new sample could be taken to analyze it by rt-PCR test at the Clinical Laboratory of the North Metropolitan health region.
The authors have highlighted that only 31.7% of the ART performed with a nasal sample gave a positive result, but they also came out positive with the oral sample.
Likewise, those ART performed with the nasal sample that indicated that the result was positive but with the saliva sample it was negative, the PCR confirmed that they were positive.