At a press conference held by the Joint Prevention and Control Mechanism of the State Council on the 15th, Li Jinming, deputy director of the National Health Commission’s Clinical Laboratory Center, said that nucleic acid testing is a “gold standard” for determining new coronavirus infection, and antigen testing cannot Alternative nucleic acid testing.
“When the antigen test is positive, the nucleic acid test must be used for confirmation. However, if the nucleic acid test is positive, no matter whether the antigen test is negative or positive, the subject should be regarded as a new coronavirus infection. Or diagnosed patients to take measures.” Li Jinming said.
Antigen detection can be used as a supplementary method for screening of specific populations, which is beneficial to improve the ability of “early detection”. According to Li Jinming, antigen detection is fast and simple, but the sensitivity of nucleic acid detection is 100 to 1000 times higher than that of antigen detection, because nucleic acid detection has an exponential amplification process. If infected with the new coronavirus, the virus content in the pharynx reaches 1 million or even 10 million per milliliter, which can be detected by antigens.
Li Jinming also said that antigen detection and nucleic acid detection have different specificities. The specificity of antigen detection can reach 99%, but methodologically, the specificity of nucleic acid detection is 100%. (Intern Li Jiayue also contributed to this article)