Recently the new crown vaccine and nucleic acid test can be said to be the news hot concern event, and with the development of the epidemic, many nucleic acid test at the beginning is negative, asymptomatic infected people, later nucleic acid test and all become positive, need to be isolated, in order to more closely cut off the source of infection, for the nucleic acid test is negative people also need to be isolated.
Then many of you will be very confused: why is the nucleic acid test negative still need to isolate ah?
Because the nucleic acid test results may be false negative. If the nucleic acid test results of the new coronavirus is negative, it does not necessarily exclude the new coronavirus infection, sometimes it also needs to be combined with the patient's condition to do specific analysis, if the patient has fever. If the patient has symptoms of fever, malaise, cough, chest CT viral pneumonia, and blood tests suggesting normal or low white blood cells, low lymphocytes and other signs of viral infection, the patient must be treated as a suspected patient for medical isolation and observation, usually after 14 days of isolation and observation, during which two nucleic acid tests are performed and the isolation can be lifted only if there are no problems.
If the novel coronavirus has mutations and the outbreak is characterized by a long incubation period, rapid transmission and complexity, some cases have taken 5-6 nucleic acid tests to show positive results. Generally, two or more throat swab tests are required to identify an infected person, and if the tests are negative, it is basically safe to be released from isolation.
A negative nucleic acid test can sometimes result in false negative results, such as improper sampling of pharyngeal swabs or improper preservation of samples resulting in "false negative" nucleic acid results, in addition, when the pharyngeal swab nucleic acid test shows negative, but also in conjunction with lgM and lgG antibodies together, when both antibodies are negative, it means that you are healthy, but also However, it cannot be ruled out that you are in the incubation period of infection, and you need to be isolated at home for observation.
How many nucleic acid tests are required to remove the isolation?
At least twice. Generally speaking, if an ordinary person has not been in contact with a newly infected person or a suspected infected person, or has been to a medium to high risk area, it is safe to do only one to two negative nucleic acid tests; however, if there is a history of previous contact, only one negative nucleic acid test can not be completely ruled out, and further observation is needed, because previous contact with an asymptomatic infected person may also become an asymptomatic infected person, during the incubation period, there is no way to accurately determine, it is best to It is best to isolate at home for 14 days and perform 2 nucleic acid tests during the 14-day period. If both nucleic acid tests are negative, a new crown can be ruled out.
Can a single positive nucleic acid test confirm neoplasia?
Generally, two or more throat swabs are required to identify an infected person, and two positive throat swabs are required to identify an infected person.
According to the description of diagnostic criteria for confirmed cases of New Coronavirus pneumonia in the "Novel Coronavirus Pneumonia Treatment Protocol (Trial Version 7)", whether a subject with a positive nucleic acid test is a confirmed case needs to be combined with clinical manifestations and other examination results such as lung CT, and only those who meet the diagnostic criteria for New Coronavirus pneumonia can be said to be confirmed cases.
If the subject has a positive pharyngeal swab for nucleic acid, but does not have clinical symptoms such as fever and dyspnea, and there are no obvious signs of viral infection on lung CT, then he or she will be considered an asymptomatic infected person, and asymptomatic infected persons also need to be placed under intensive medical observation.
How long does it take to get the results of the nucleic acid test?
Routine tests generally take 4 to 6 hours to produce results.
Nucleic acid testing is currently the most effective test for early determination of infection with the new coronavirus. The standard process includes manual sample processing, nucleic acid extraction on the machine, manual addition of nucleic acid template, PCR amplification on the machine, and result analysis and reporting in five steps, all of which require professional technicians to operate and analyze, which is very demanding for the laboratory and the workload is very high, so routine testing generally takes 4-6 hours to produce results.
Attention.
Depending on the population and the epidemic prevention and control management policies of different regions, the validity of nucleic acid test results or reports should be somewhat different, for example: the valid nucleic acid test report for people traveling in high-risk areas in China is within 7 days.
