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After approval by the Ministry of Health, it is expected to expedite its distribution in health centers throughout the country.
The initiative baptized as 'Strategy for early detection, surveillance and control of covid-19 already has new tools. The Ministry of Health, promoter of the campaign, has approved the use of the antigen test for this purpose, to complement the PCR tests, expedite the prevention measures resulting from the analyzes in the offices of the National Health System and give a respite to the laboratories.
How the antigen test is done
The test is done through the nasopharyngeal route, as is the case with PCR, but the swab must be inserted through both nostrils. The rest of the operation is a bit similar to the pregnancy test. They are small rectangular devices with a few drops that serve as a reagent: after taking the sample with both sides of the swab, topped with cotton swabs, and applying them to the liquid in the device, wait 15 minutes; What we are looking for is specific proteins (antigens) that are present on the surface of the virus.
Detecting its presence with the test is confirmation of an active infection; Therefore, the person tested and infected is a transmitter of the disease and, as occurs for prevention in PCR tests, must be isolated immediately. The result arrives in 15 minutes; Visually, it appears with one line (control value) for negative and two lines (control and infection) for positive, just as it happens in the pregnancy test. Antigen tests can detect Covid-19 proteins from two days before the appearance of symptoms, and the first week after the onset of the disease. The average efficiency is greater than 95%.
Your contribution to the current situation
If they maintain the level of sensitivity and effectiveness above 95%, they will be essential to avoid saturation in primary care. They already existed in the first months of the pandemic, but their sensitivity then was very low, around 30%, and logically they were not practical. In addition, their cost is significantly cheaper than that of PCR tests: 4,5 euros, compared to almost 100 for PCRs.
The other test commonly used in this pandemic is the serological test, which belongs to a different family. The key difference between a positive in antigens or PCR and another in the serological test is that the latter detects antibodies, which means that the person tested had the virus, but no longer has it active.
