I believe that this year we are not unfamiliar with the "nucleic acid test", but with the major news media coverage of it, from the beginning many people do not know how the nucleic acid test in the end, to now heard that some are blood, some are throat swabs, some or nasal swabs, directly poked inside the nose, to how uncomfortable. These rumors make a small number of people who would have liked to do a nucleic acid test, now become very apprehensive, and even make a part of it has been unclear in the end to do the kind of test is good, is right? Some people are torn between blood sampling and pharyngeal swab, is it better to have a pharyngeal swab or blood sampling? So what is the difference between a pharyngeal swab and a blood draw for the new crown test? Let's find out

New Coronavirus testing is currently divided into two main types of nucleic acid testing and (blood) antibody testing, generally speaking, in the clinical diagnosis, the combination of the two tests to determine whether the tested person is infected with the virus and the stage of the disease.

The pharyngeal swab is taken from the patient's respiratory secretions to detect the RNA of the virus in the secretions to see if the patient is infected with the virus. The specimen taken for the blood draw is taken from the patient's blood and used for antibody testing to see if there are antibodies in the patient's blood that have been stimulated by the virus and to detect whether the patient is infected by the virus and the stage of the disease. The higher the viral load, the greater the likelihood of a positive nucleic acid test. Theoretically, viral nucleic acid can be detected within 1 to 2 days of infection.

Regardless of the disease, blood tests are an essential part of the clinical workup. For the new coronavirus, routine blood tests can help the doctor first identify whether the infection is bacterial or viral. If the patient's peripheral blood count is normal or decreased and the lymphocytes are decreased in routine blood tests, then it is very likely that the infection is viral, and then combined with the patient's rheumatology and symptoms and signs, the doctor is able to determine whether the patient is a suspected case of new coronavirus infection before the subsequent viral nucleic acid test. So in this respect, the blood test is also helpful in screening for neo-coronavirus.

While nucleic acid test results for new coronavirus are an important reference for the diagnosis and efficacy evaluation of novel coronavirus pneumonia, screening specimens for nucleic acid testing are mostly derived from deep cough sputum or pharyngeal swabs. Since oropharyngeal swabs are relatively simple to perform with an open mouth, they are more commonly used in clinical practice. However, if the pharyngeal swab is not performed properly, it may result in a "false negative" result, which may delay the patient's treatment. Therefore, the nucleic acid and blood antibody tests need to complement each other to confirm the presence of infection and the status of the patient.

Currently, pharyngeal swabs are more commonly used for nucleic acid testing in China.