Antigen Covid Test
We routinely test the nucleic acid with nasal swabs in the department every week, and we have been used to it for several months.
At most, it will pass with a tear and clenched teeth (naive).
So when I was queuing, I didn’t think there was anything to do mentally, and I didn’t notice that the head nurse was training a new little nurse how to do nucleic acid today‼ ️
As a result, it was my turn, and as soon as I sat down, I heard the head nurse say, “I’ll show you one.”
So before she could react, she stabbed in at once, and that feeling, I have never felt so uncomfortable in my life, from nostrils to throats.
It felt like my head was split open, and tears came out. The nasal swab is about 15cm long. According to my classmates, there are only 2cm left.
And because I was so overreacting (yelling and leaning back so fast), the head nurse was so startled that I didn’t have time to pull it out.
The covid flocked swab didn’t come out even after she let go, and I pulled it out with tears.
Many Americans are familiar with the rapid antigen test for COVID-19, which involves swabbing the nose.
What is an antigen test? Can it replace nucleic acid detection (PCR swab test)?
What is an antigen test?
The new coronavirus antigen detection is detected on a test strip through the binding reaction of antigen and antibody.
which is convenient and quick, and the result is usually available in 15-20 minutes.
However, due to the existence of some interference, the antigen-antibody reaction may be falsely positive.
The specificity of the method is less than 100%.
Therefore, antigen test results cannot replace nucleic acid test results.
There are three main methods to detect whether the virus invades the human body: nucleic acid detection (PCR), antigen detection and antibody detection.
The first two are methods of direct detection of viruses.
Compared with nucleic acid detection, antigen detection can be faster and more convenient to operate.
But with lower accuracy, generally used in the initial stage of infection.
After the outbreak, many countries, while recognizing nucleic acid testing as the “gold standard” for COVID-19 testing, have also promoted antigen testing as an effective supplement.
Antigen-positive results can be used for early triage and rapid management of suspected populations.
1. Why do I need an antigen test?
Facilitates “early detection” The new coronavirus mainly has four structural proteins.
Compared with nucleic acid detection, antigen detection is faster and more convenient to operate, and some reagents can produce results in 15 minutes.
Faster and more accurate epidemic prevention and control requires additional antigen testing as a supplement.
Once the antigen test is positive, we need to carry out nucleic acid testing to confirm in time.
2. Why can’t it replace nucleic acid detection?
or false detection According to the latest plan, nucleic acid testing is still the basis for the diagnosis of new coronavirus infection.
Antigen detection is a supplementary method and cannot replace nucleic acid detection.
The reason is that the sensitivity of antigen detection is relatively low. And antigen detection products can usually only be detected when the infected person is in the acute infection stage.
That is, when the viral load in the body is at a high level.
Compared with nucleic acid detection, antigen detection has poor sensitivity due to no amplification process.
In layman’s terms, it shortens the time for results, but increases the risk of “false negatives”.
According to the above plan, if the primary medical and health institutions have nucleic acid detection capabilities, nucleic acid detection should be the first choice;
If they don’t have nucleic acid testing capabilities, they can do antigen testing.
In the current epidemic, there are many asymptomatic infections.
Can we get through testing?
From the existing data, a large part of the infected people of the Omicron variant are asymptomatic, but it does not mean that their viral load is low.
On the contrary, some studies have shown that the viral load in the throat of some asymptomatic infected people is quite high.