On April 25, Shanghai held a press conference on the prevention and control of the new crown pneumonia epidemic.
At the meeting, in response to some residents' belief that "nucleic acid testing does not need to be done frequently, and self-testing of antigens is enough", Hu Xiaobo, director of the Shanghai Clinical Laboratory Center, responded that nucleic acid testing is mainly used to determine whether an individual is infected with the new coronavirus. High sensitivity detection method.
Nucleic acid detection is an exponential amplification process that makes the virus easier to detect by appropriately amplifying the concentration of virus fragments.
"If a person is still in the early stage of infection and relevant signs have not appeared, then the antigen test may be negative, and nucleic acid testing is required to confirm. The accuracy of antigen testing also depends on the standardization of individual operations. Antigen testing cannot Instead of nucleic acid testing."
Hu Xiaobo said that the recent continuous screening is mainly based on this consideration. From the perspective of the course of the new coronavirus infection, there is a certain incubation period. At the same time, different individuals have different viral loads.
When the community completes a round of nucleic acid screening, usually those infected with higher viral loads can be screened, but some infected individuals with lower viral loads will show negative nucleic acid results.
Therefore, it is necessary to dynamically detect positive infected persons as soon as possible through continuous nucleic acid screening, and realize the dynamic clearing of social aspects as soon as possible.
(Reporter Kang Yuzhan)
Responsible editor: [Liu Pai]