There is no need to scramble for the new crown antigen self-testing agent

  Recently, "antigen detection" as a supplementary detection method for the new coronavirus has become a hot spot of public attention.

It is understood that the first batch of new crown antigen self-test kits have been sold on major pharmaceutical e-commerce platforms and offline chain pharmacies, and many kits were snapped up as soon as they were put on the shelves.

Experts said in an interview with a reporter from Economic Daily that antigen testing should be used for the detection of high-risk and high-prevalence clustered infection groups, and the general population does not need to compete for the new crown antigen self-testing box, let alone stock up.

  The reporter searched for "new crown self-test" on Taobao and saw that Ali Health has begun to sell various specifications of new crown antigen detection kits, of which the price of 1 person is 25 yuan, and they will be shipped within 10 days after payment.

According to the staff of the Hanzhong Road store of Yifeng Pharmacy in Nanjing, the store began to sell the spot new crown antigen detection kits on March 15, and the price is 376 yuan for 20 people.

It is understood that in addition to Nanjing, cities such as Hangzhou and Shanghai have also launched new crown antigen detection kits.

  What are the advantages of the new crown antigen self-test?

Li Jinming, deputy director of the National Health Commission's Clinical Testing Center, said that antigen testing is convenient and quick to detect antigens through the binding reaction of antigens and antibodies.

Mutant strains such as Omicron are highly contagious, posing challenges to epidemic prevention and control.

In some grassroots areas that do not have nucleic acid detection capabilities, or for some centralized isolation personnel with relatively high risk of infection, the use of antigen testing can eliminate the need for specialized laboratories and complex instruments, and test results in a shorter time.

"It can move the threshold of early detection forward, saving a lot of time and manpower for subsequent precise prevention and control."

  It should be noted that antigen detection cannot replace nucleic acid detection.

Nucleic acid testing is still the "gold standard" for determining new coronary pneumonia infection.

Li Jinming said that the sensitivity of nucleic acid detection is 100 to 1000 times higher than that of antigen detection.

If you are infected with the new coronary pneumonia virus, the virus content in the pharynx has a process from less to more. If the content reaches 1 million or even 10 million per milliliter, most of them can be detected by antigen at this time.

A well-done antigen test has a specificity of 99%, but a nucleic acid test has a methodological specificity of 100%.

That is to say, nucleic acid testing has no false positives methodologically.

When the antigen test is positive, nucleic acid testing must be done to confirm.

  "Antigen detection should be used in the detection of high-risk, high-prevalence clustered infection groups. There is no need for the general population to do antigen detection." Li Jinming said when talking about groups that need to use self-test kits, first of all, they do not have nucleic acid detection capabilities. Persons with symptoms such as respiratory tract, fever, and symptoms within 5 days.

Second, quarantine observation personnel, including home quarantine observation, close and sub-close contact, entry quarantine observation, closed and controlled areas, and personnel in control areas.

Finally, community residents who need self-testing, such as some residents who feel that they have accidentally touched items that may contain the new coronavirus and are worried about being infected, can use the method of antigen testing to self-test.

"The frequency of antigen testing is good once a day, and it does not need to be too frequent."

  The reporter noticed that according to the "Basic Requirements and Procedures for New Coronavirus Antigen Detection in Primary Medical and Health Institutions", antigen samples are divided into three categories: nasopharyngeal swabs, oropharyngeal swabs, and nasal swabs. The operator chooses to collect according to the requirements of the reagent instructions used. .

When doing nucleic acid testing, oropharyngeal swabs are basically used, which need to be collected by professional medical staff; for residents in centralized isolation, the method of double sampling of oropharynx and nasopharynx is generally used to ensure accuracy.

Nasal swabs are relatively easy to use and suitable for residents to self-test at home.

  What should I do if my self-test is positive?

Jiao Yahui, director of the Medical Administration and Hospital Administration of the National Health and Health Commission, said that if a resident tests positive for antigen at home, they should report it to the community in their jurisdiction. Nucleic acid testing shall be carried out by medical institutions with testing conditions.

If the nucleic acid test is positive, it will enter the infected person management process.

In addition, the used swabs, test tubes, and test cards should be put into sealed plastic bags, and the staff will take them away when they come to the door and hand them over to medical institutions for disposal as medical waste.

Our reporter Wu Jiajia