What is an antigen test?Who needs an antigen test?

2022-05-03 0 By

Recently, in order to further optimize the novel Coronavirus testing strategy and serve the needs of epidemic prevention and control, the Joint Prevention and control Mechanism Of The State Council decided to add antigen testing to nucleic acid testing as a supplement.What is novel Coronavirus antigen test?What’s the use?Who needs an antigen test?How do individuals operate?A few days ago, the reporter interviewed li Jinming, deputy director of the Clinical testing center of the National Health Commission.What is the use of novel Coronavirus antigen tests?”Novel Coronavirus antigen testing can indirectly reflect novel Coronavirus infection.”According to Li Jinming, novel Coronavirus has four structural proteins, among which N protein is the most expressed.N proteins appear in the throat in individuals infected with novel coronavirus.Antigen detection is the detection of N protein, and the detection of N protein can indirectly reflect the infection of novel coronavirus.Antigen detection differs from nucleic acid detection in specificity and sensitivity.Li Jinming analysis, antigen detection specificity can reach 99%, and nucleic acid detection of the specific performance of 100%.Specificity is the probability that a positive test result will actually infect the Novel coronavirus.Due to China’s good epidemic prevention and control, the novel coronavirus prevalence rate may only be one in a million, and false positives may occur with the use of antigen tests.But it doesn’t matter, once the antigen test is positive, the nucleic acid test can be further confirmed.Antigen tests are less sensitive than nucleic acid tests, but are easy to detect if the infection is early and the virus concentration is high.”Novel Coronavirus antigen tests can be used as a complementary test for population-specific screening and can help improve ‘early detection’ capabilities.”Li jinming said the emergence of mutant strains such as Omicron, which are highly contagious, has brought challenges to epidemic prevention and control.By using antigen testing in grass-roots areas where nucleic acid testing is not available, or for those quarantined in a concentration with a relatively high risk of infection, it is possible to find the source of infection in a shorter time without special laboratories and complex instruments.This can reduce the work intensity of nucleic acid sampling and detection personnel, but also can be a means of virus detection.”It is important to stress that antigen testing is not a substitute for nucleic acid testing.Nucleic acid tests remain the basis for confirmation of Novel coronavirus infection.”Li said that in the process of nucleic acid test confirmation, if nucleic acid test is positive, regardless of antigen test result is positive or negative, corresponding measures will be taken in accordance with novel coronavirus infection or COVID-19 confirmed cases.Who should be tested for novel Coronavirus antigen?Who should be tested for novel Coronavirus antigen?Li said that the first is to go to primary medical and health institutions that do not have nucleic acid testing capabilities, with respiratory symptoms, fever and other symptoms within five days of symptoms.Secondly, quarantine observation personnel, including home quarantine observation, close contact and sub-close contact, entry quarantine observation, containment area and control area personnel.Third, community residents with a need for self-testing, for example, those who think that they have accidentally come into contact with objects that may contain novel coronavirus virus, fear that they may be infected, and take self-testing by means of antigen testing.”Antigen testing should be done only once a day, not too often.”How do autonomic antigen tests work?How to perform autonomous antigen detection?The first step is sampling.People over the age of 14 can take nasal swabs themselves, Li said.Self-examiners blow their noses with toilet paper first.Unpack the nasal swab carefully and avoid contact with the swab head.Then tilt your head back slightly, hold the swab with the tail of one hand to one side of the nostril, and slowly penetrate 1 to 1.5 cm backward along the bottom of the lower nasal canal. Then apply the swab to the nasal cavity and rotate it at least 4 times, staying for no less than 15 seconds. Then repeat the same operation with the same swab to the other nasal cavity.Those aged 14 and under should be sampled by a parent or other adult.Step two, antigen detection.Li Jinming introduced that, according to the reagent instructions, the nasal swab should be placed in the sample tube immediately after sample collection. The swab head should be rotated and mixed in the preservation solution for at least 30 seconds, and at the same time, the swab head should be squeezed through the outer wall of the sample tube for at least 5 times to ensure that the sample is fully eluded in the sample tube.Squeeze the liquid from the swab head through the outer wall of the sample tube and discard the swab.After the sample tube is covered, the liquid is dropped vertically into the sample hole of the detection card.According to the reagent instructions, wait for a certain time to interpret the results.Positive results: both “C” and “T” showed red or purple bands, and the color of the band at “T” could be dark or light, which were all positive results.Negative results: red or purple bands were shown at “C” and no bands were shown at “T”.Invalid result: No red or purple band is shown at “C”, regardless of whether a band is shown at “T”.Invalid result, need to take a new strip test again.As shown below: “Be cautious about waste disposal after antigen testing.”Li jinming said that for quarantine observation personnel, no matter the test results are negative or positive, all used samples, sampling tubes, test cards, etc., will be put into sealed bags for management personnel to refer to medical waste or according to procedures.For ordinary residents, if the test results are negative, all nasal swabs, sample tubes and test cards after use shall be put into sealed bags and disposed of as general waste;If the test results are positive, they will be transferred to medical institutions for treatment as medical waste.How to deal with positive test?Those who test positive in primary-level health care institutions should immediately report to local CDC departments, and the emergency centers will transfer the antigen-positive patients to medical institutions with fever clinics for nucleic acid tests in accordance with guidelines for the transfer of COVID-19-related personnel, Li said.If quarantined observers test positive, nucleic acid tests should be conducted immediately to confirm.To residents with antigen detection, detect the positive, regardless of whether there is respiratory tract, the symptom such as fever, residents shall promptly report to the community (village), contact emergency services by community (village) in accordance with the relevant personnel COVID – 19 outbreak by transshipment work instructions, set the residents to fever outpatient medical institutions, detection of nucleic acids.Source: CCTV news news clues breaking channel: application market download “morning video” client, into the “Morning help” topic;Or call the morning video news hotline 0731-85571188.