China News Service, Beijing, May 19 (Reporter Chen Hang) Liu Xiaofeng, deputy director of the Beijing Center for Disease Control and Prevention, said at a press conference on Beijing's new crown pneumonia epidemic prevention and control work held on the 19th that domestic nucleic acid detection reagents are not subject to virus mutation. influence, is sensitive and reliable.
Liu Xiaofeng said that at present, nucleic acid detection of new coronary pneumonia is the most effective and accurate virus detection method, and it is also an important means to deal with epidemic prevention and control.
In terms of technology, although the virus is constantly mutating, my country's new coronavirus nucleic acid detection reagents are designed for conservative sequences with fewer new coronavirus mutation sites. Therefore, domestic nucleic acid detection reagents are not affected by virus mutation and are sensitive and reliable. .
Liu Xiaofeng introduced that antigen detection is a faster detection method for virus detection. The detection time required is between 15 and 20 minutes, while the nucleic acid detection time is between 4 and 6 hours. Therefore, compared with nucleic acid detection, antigen detection has "faster" At the same time, for high-risk groups, antigen detection also has the advantage of high specificity.
Experts from the Clinical Testing Center of the National Health Commission pointed out that the sensitivity of antigen detection reagents approved in my country is between 75% and 98%, and the specificity is between 95% and 99%. If used in a high-risk population with a prevalence rate of 5% With a kit with a sensitivity of 85% and a specificity of 97%, about 60% of the people with positive antigen tests have positive nucleic acid tests, with high specificity. The nucleic acid test of most people who tested positive for antigen was negative, and the specificity was not high.
On the other hand, the PCR technology of antigen detection without nucleic acid detection amplifies the virus signal, does not have the process of signal amplification, and is less sensitive than nucleic acid detection.
Liu Xiaofeng said that, in view of the above reasons, the comprehensive team of the State Council's joint prevention and control mechanism for the new coronavirus pneumonia epidemic has made it clear that nucleic acid testing is still the basis for the diagnosis of new coronavirus infection, and antigen testing as a supplementary method is mainly used for high-risk groups. Discovery ability.
Regarding the requirement of 10 days for the last nucleic acid test during the closure and control period, Liu Xiaofeng introduced that the closure and control area and the personnel in the control area will conduct a nucleic acid test on the 1st, 3rd, 5th, 7th and 10th days after the control, respectively. 2, 4, 6, and 8 days for antigen self-test.
Among them, the full 10 days represents the 11th day since the date of closure and control.
For example, during the lockdown and control period, the nucleic acid test results of all personnel are negative, and the last close contact has been away for 4 days or more and the nucleic acid test result is negative. The department will unblock it on the basis of full evaluation.
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