If there is some time and space intersection with the positive COVID-19 person, many friends may be a little worried about whether they will accidentally get infected with COVID-19 . Can you feel at ease if you get negative nucleic acid once? If you accidentally get infected with the new coronavirus, how many days will the nucleic acid be detected? This article is for communication and discussion only, and the specific details shall be subject to the official!
1. Factors affecting the results of nucleic acid detection
1. Viral load in the infected person
1. Viral load in the body of the infected person
After the virus infects the human body, the virus concentration in the body is very low at the beginning, which is a latent period. Both nucleic acid and antigen cannot be measured. Later, the virus begins to replicate and amplify continuously, and can only be detected when the virus amplifies to a certain concentration. In other words, before the virus in the body amplifies to a detectable concentration, even if it is infected with the new coronavirus, the nucleic acid test will always show a negative result, resulting in missed tests.
Viral load at different times
2, sampling and detection related links
Sampling, transportation, detection links, etc. are directly related to the accuracy of the results. This principle is very simple. Each link in making buns determines the appearance and taste of the final buns.
3, quality of reagents and consumables
The reagents, instruments, and consumables used in the relevant process of detection will affect the final detection results. Just like the flour, filling, steamer, etc. used to make buns will affect the quality and taste of the finished buns.
2. Generally, nucleic acid positive can be detected in 3-7 days
The initial stage after infection with the new coronavirus is the incubation period. This stage has low viral load and no symptoms, so the nucleic acid test may be negative during the incubation period. The incubation period of the new coronavirus is usually 1-14 days, and most are 3-7 days. This is related to the type of new coronavirus infected, vaccination status, autoimmunity, etc.
3. After symptoms, nucleic acid will be detected under normal circumstances. When you are infected with the new coronavirus, you will start to have symptoms, such as a sore throat and cough, which means that the virus has reached a certain concentration in the body. In this case, nucleic acid tests can be detected normally.
graphic and text irrelevant
4. Is there any positive test that is not tested 14 days later?
Although the incubation period for most people to be infected with the new coronavirus is less than 14 days, a small number of people have incubation periods of more than 14 days. In fact, there are not only 14 days, but even 3 or 4 weeks before nucleic acid positive cases were detected, but the proportion was very low.
Li Zhili and others published in the 2nd issue of the Chinese Journal of Epidemiology, 2022. They collected data on imported new coronavirus infections reported by provinces from July 24, 2020 to July 23, 2021, and analyzed the time distribution characteristics of the first positive nucleic acid after entry. Results From July 24, 2020 to July 23, 2021, a total of 7,199 imported cases of new coronavirus infection were reported in 28 provinces across the country. The time interval from entry to the first positive nucleic acid was 1 (0,5)d. Among the imported COVID-19 infections, 95.15% (6850/7199) and 4.85% (349/7199) were the first positive nucleic acid tests within 14 days and after 14 days, 3.65% (263/7199), 0.88% (63/7199) and 0.32% (23/7199) were the first positive nucleic acid tests within 15~21 days, 22~28 days and after 28 days, respectively.
5. How to deal with
In summary, the nucleic acid test results will be affected by various factors such as incubation period, specimen collection, detection links, instruments and reagents, and there may be false negatives. If you have a history of close contact with the new coronavirus, do not just look at the results of a single nucleic acid test. You need to conduct multiple nucleic acid tests to confirm whether you are infected. Before this, please take protective measures to avoid the spread of the epidemic.
We focus on introducing the relevant knowledge of COVID-19 antigen detection and nucleic acid detection. If you have some questions about COVID-19 testing, you are welcome to communicate and discuss with each other.
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