Recently, there have been a lot of good news about innovations in virus testing, from the initial days-long nucleic acid test, a variety of ideas and implementations have been added, and the time to get test results has been reduced from days to hours, and even the latest technology claims to give results in minutes.
At the same time, however, news of inaccuracies in kits and other testing methods has been reported. Terms such as "throat swab", "PCR", and "antibody/antigen" fly around, making it daunting to get infected with a virus while also being daunted by the variety of testing technologies available.
Many people may have similar questions: How long does the test take? What is the accuracy?
I. Conventional nucleic acid testing
Direction: Genetics Method: RT-PCR Reverse transcription polymerase chain reaction Detection object: the virus gene itself Accuracy: the highest time: a few hours to a few days Advantages: high accuracy, is currently the only basis for confirming the diagnosis Disadvantages: long time, high threshold of professional operation
New coronavirus is an RNA virus that can replicate itself when it enters and infects the body. As long as the person is infected, the virus must be present in the body. However, because the virus is too small to be seen under a microscope, it cannot be confirmed by direct observation.
Sample collection.
The term "pharyngeal swab" should not be new to you, as it is the primary source of samples for NIV testing. In simple terms, a plastic stick is used to reach deep into the patient's throat to collect some respiratory fluid, which is then encapsulated, refrigerated, and sent to a laboratory for RT-PCR testing.
Experts soon found, however, that the results from swab samples alone were inaccurate and had a high chance of false negatives. Therefore, in different countries or regions, frontline health workers may also collect nasal swabs, sputum, stool and other samples together with the test.
Second, rapid bedside molecular testing
Direction: genetics test object: the virus gene itself accuracy: unknown, close to the conventional RT-PCR time: as fast as 5 minutes advantages: fast, low threshold of operational expertise disadvantages: unclear (accuracy remains to be seen) bedside molecular detection method, the biggest advantage is fast, no need to transport cold chain preservation, that is, the measurement is out. And because it is a nucleic acid test, it can be used as an authoritative basis for confirming the diagnosis. However, there is no conclusive evidence as to how accurate it is or how different it is from conventional PCR.
Three, serum antibody test
Direction: serological test object: the formation of antibodies after infection accuracy: lower than the first two time: as fast as 2 minutes advantages: fast, safe for the sample collector disadvantages: the length of the patient's infection limit, the results are not accurate enough to be used as a basis for confirmation of the diagnosis
Virus testing is a matter of fish and bear's paw in general.
Methods that detect accurately, are the slowest.
Fast method, but accuracy is a problem.
The most authoritative test is severely under-resourced for kits.
The method with sufficient resources, the results cannot be used independently as a basis for confirming the diagnosis.
