Throat swab is a method of nucleic acid detection
The new coronavirus nucleic acid test is the most important method to diagnose the new coronavirus. Nucleic acid is the genetic material RNA of the new coronavirus. The nucleic acid test is to check a certain segment of RNA. If it is positive, it means that you are infected with the new coronavirus.
According to different sampling sites, nucleic acid detection can be divided into many types, such as throat swabs, anal swabs, tracheal secretions, alveolar lavage fluid, and so on.
Among them, throat swabs are the most commonly used, and oropharyngeal or nasopharyngeal secretions are taken for laboratory tests.
How to do a throat swab? Painful?
What is done is an oropharyngeal swab, the inspection process is very fast, no more than 10 seconds, only needs to open the mouth, and the staff uses a cotton swab to take a sample in the oropharynx.
When sampling, there will be a slight pain, and when the throat is stimulated, there will be a feeling of vomiting, but the feeling is not strong, and it will be fine for a while.
According to the reaction of colleagues, nasopharyngeal swabs are more uncomfortable, and the pain will be greater, because the cotton swab needs to be completely inserted into the nose.
How to interpret the results
Nucleic acid testing usually produces results within 24 hours. Check today and you will know the results the next day. The results are nothing more than two cases, negative or positive.
Does negative mean there is no infection?
It is not 100% sure, because nucleic acid testing has a certain probability of false negatives. For example, in the early stage of the disease, the virus content is very low, and it may not be detected, or the sampling is not taken properly, and the sensitivity of the detection reagents, operation Whether it is standardized or not, etc., are affected by many factors.
With the continuous optimization of detection methods and the continuous updating of reagents, the sensitivity of detection is now higher, and the probability of false negatives is lower than before.
If it is negative, there is a high probability that it has not been infected with the new coronavirus. For some high-risk groups, close contacts, and suspected clinically highly suspected cases, one negative may not be enough, and two, three, or even multiple tests may be required.
How to interpret a positive result?
A positive result means that you are infected with the new coronavirus, but it can be divided into three situations:
The first type, confirmed patients
If the patient's throat swab is positive and has symptoms such as cough, fever, dyspnea, sore throat, and CT suggests lung inflammation, then it can be diagnosed as a patient with new coronary pneumonia.
The second type, patients with incubation period
Except for a positive nucleic acid test, patients in the incubation period have no clinical symptoms. The incubation period refers to the period from infection with the new coronavirus to the appearance of clinical symptoms, which is generally 3 to 7 days, less than 14 days.
Patients in the incubation period are also contagious and need to be isolated and closely observed. After clinical symptoms appear, they can be diagnosed as patients with new coronary pneumonia.
The third type, asymptomatic infection
If the patient remains asymptomatic during the observation period, it is an asymptomatic infection. There is a difference between an asymptomatic infection and an incubation period, and an asymptomatic infection has never experienced any discomfort.
Asymptomatic infections are also contagious and need to be quarantined and then closely observed until the body’s immune system has overcome the virus and the nucleic acid turns negative before being released from quarantine.
