Most of the currently available antigen testing kits are sampled by nasal swab. Why do I need to sample the nasopharynx?
Antigen testing is mainly for the detection of proteins on the surface of the virus, which is specific and easy to perform with fast results. However, compared to nucleic acid testing, antigen testing is not as sensitive. The nasopharynx has more secretions, and if infected with the virus, this area will contain a little more virus than the oropharynx. The antigen test will be more accurate when the sample is taken at this site.
How do I find the right nasopharynx when sampling myself?
The nasopharynx is located directly opposite the posterior nostril. What we usually see is the anterior nostril, which is like a "front door", and the posterior nostril is like a "back door". The cotton swab enters the nasal cavity through the "front door" and passes through the "back door" where it hits a "wall", which is the nasopharynx.
At this point, the swab is almost perpendicular to the face, and then the swab leans down a bit to reach the nasopharynx. In short, the swab should be "vertical, down and back" to find the right nasopharynx.
Some people may feel that the swab does not go in, or feel pain in the nose after stabbing, why would this happen?
In the middle of the two nostrils there is a nasal septum, like a "wall" between the two sides of the nasal cavity. But this "wall" is not always straight, many people are born with a little deviation of the septum, if relatively mild will not affect life, if serious may cause unilateral nasal congestion, nosebleeds, sinusitis, etc., such people need to seek timely medical attention. Other people may have a deviated septum due to trauma or other diseases.
Deviated nasal septum can cause the nostrils to be slightly larger on one side and smaller on the other. Therefore, when sampling, if you feel that one nostril resistance, it is recommended not to "hard stab", you can change the nostril on one side, the cotton swab lean down, lean back slowly into. If the swab is in the wrong place, or if the force is too strong, the swab may hit the inferior turbinate, which will be more painful.
Can children be sampled by nasal swab?
Infants and children have small nostrils and need to be sampled by pharyngeal swabs. Adolescent children can be sampled by nasal swab with the help of their parents, and the movements must be patient and gentle.
