One of the most conclusive studies was carried out at the University of Cape Town, in South Africa. In it, the self-diagnosis tests of 382 patients already infected with Covid-19 were compared. In those with the delta variant, saliva samples detected the COVID-2 71% of the time, while the nasals did it 100%. On the contrary, With omicron-infected patients, saliva samples detected the virus 100% of the time.
For its characteristics, The latest variant of Covid-19 would thus be mostly detectable in antigen tests performed orally. "Colonization in the oral mucosa is greater in this variant, that is, there is more viral load in the throat area than in other areas," explains the pharmacist Pablo García.
This man from Malaga, who works in the pharmaceutical industry, assures that these tests have very high reliability and sensitivity. The operation is practically identical to conventional antigens. Both tests include the strip where the result will appear and a solution with a buffer where the sample will be placed. In addition, saliva tests will include a container in which to deposit the sample, instead of the famous swab.
This professional indicates, however, that both tests have a high degree of reliability, as long as they are carried out properly. "The two options are still reliable but it is true that there is a "higher percentage of efficacy through the oral mucosa".
García also warns about the myths that are spreading around this diagnostic test: "All the videos that are being seen now in which orange juice or water is poured onto the strip, this happens because they are very sensitive to the PH variations, it is normal that it gives an erroneous result." For all these reasons, this expert insists on a correct performance of any type of diagnostic test.
Saliva tests have been available to citizens in all areas for some time now. pharmacies. To date, its use was more limited to testing young children, since it is more convenient and nasal mucosa tests were more effective in detecting other types of variants.
Now, the sale of these tests is expanding due to the high degree of reliability they promise. "The purchase of antigens it shot up after christmas but it is true that saliva tests were sold but not at the same level. Now is when we are observing that sales are increasing," says García.
