For more than a year, the COVID-19 pandemic has turned our world upside down. But one thing we have learned: mass testing is, besides the vaccine, one of the important tools by which SARS-CoV-2 can be kept under control. 

What is the rapid antigen test? How are samples collected and how are the results interpreted? These are some of the questions we answer below. To further understand how testing works, you should reach out to a covid test clinic in Los Angeles for more essential information.

What is the rapid antigen test? 

If, until now, we all knew about the classic RT-PCR test, which remains the gold standard for the diagnosis of COVID-19, we now have a new official aid (according to the authorities' updated case definition): the rapid viral antigen detection test for the new type of coronavirus. This test provides a response, in about 15 minutes, and can contribute significantly to reducing the infection rate and limiting the spread of the virus. In short, the sooner the infected person receives the result, the sooner they can isolate themselves and avoid infecting others. 

The rapid antigen test is an in vitro diagnostic test that is the newest type of test for SARS-CoV-2 infection. This type of test detects antigens, i.e. the part of the virus that our immune system recognises. 

Rapid antigen testing indicates infection in the acute phase of the disease. It should therefore be remembered that the timing of sample collection is extremely important. The earlier it is done, i.e. at the onset of symptoms, when the samples contain the highest viral titers, the greater the chance that the result will be as clear as possible. On the other hand, samples obtained after five days of symptoms may give false negative results compared to an RT-PCR test, which has a higher sensitivity. 

Rapid antigen testing should only be done in health facilities, by qualified medical personnel, not at home in the living room. If samples are taken improperly, obviously the result can also be wrong. 

How are antigen testing samples collected? 

Collecting samples for the rapid antigen test is not complicated. The procedure is similar to the RT-PCR test and involves collecting a secretion either from the nose (preferably) or from the throat using swabs with swabs. After the samples are taken, they are placed in a special solution, from which a few drops are placed in the test box, in the place dedicated to the sample. So simple. Now all you have to do is wait for the result. It will be read in about 15 minutes. No later. 

Results interpretation 

The result is easy to interpret. The test box has two letters and the meaning is as follows: 

l  C - is the control region;

l  T - is the test region. 

In case of a negative result, a red line will appear next to the letter C, i.e. in the control area. 

This can have two meanings: 

l  there are no particles of the new coronavirus in the sample; 

or 

l  the viral particle count is below the detectable range. 

The presence of the two lines confirms infection with Sars-CoV-2. 

If no line or only one line appears in the T-zone, i.e. the test zone, the result is invalid and the whole process has to be redone.  

It is also important to mention that tests can remain positive for a longer period of time, even after you have recovered. If it has been 14 days since the first positive test and at least 72 hours since you have no symptoms, then you are no longer considered contagious. Repeat testing is not recommended within the first 90 days of diagnosis. To return to work, your employer may require a negative test result. Also, if your health condition required hospitalization and your symptoms disappear before 14 days and you are discharged, you are obliged to continue to isolate yourself at home for the rest of the remaining period. 

Rapid antigen testing can be a valuable tool in diagnosing and controlling the spread of COVID-19. Don't hesitate to ask for help at the first sign of symptoms or if you have come into contact with someone who is positive.