You may find people crying and saying things like, “My father passed away because of this pneumonia, and it is not in the statistics table. I am also infected, but I still can’t diagnose it, please help me!” Such words got common since the coronavirus came. It is better if we detect coronavirus well in time for which COVID testing kit is needed. Information about these are easily available with the bio medical sites like biotb.com or scientific research journals and sellers are listed on Google business listings.
It is understood that currently in the world, only hospitalized and highly suspected cases can carry out the “2019-nCoV kit test” to confirm the diagnosis of new coronavirus pneumonia.
According to incomplete statistics, at least 80 IVD companies have developed new coronavirus (2019-nCoV) detection kits.
So, why is the dilemma of “hard to find a box” for the new coronavirus detection kit? Are there too few enterprises capable of producing? Or are testing labs and personnel unable to keep up?
In this regard, according to experts there are mainly the following reasons:
1. During the Spring Festival, the production workshop of reagent raw materials, logistics and distribution, and personnel are seriously insufficient, and the production capacity of test kits is limited.
2. The short board of logistics. Many kits need to be transported in the cold chain, but during the Spring Festival, the capacity is tight.
3. At present, only few products have been approved, and most of the kits have not obtained the registration certificate.
Once there is a missed diagnosis, the follow-up risk enterprises will be difficult to bear.
4. Improper use can easily lead to cross infection. At present, the kit used to detect the new coronavirus needs to be used in conjunction with a PCR instrument. But the PCR instrument needs to detect multiple infectious items at the same time. If it is done at the same time with other items, there will be a risk of cross-infection, which will undoubtedly bring great danger to the laboratory. big challenge.
5. The number of biosafety laboratories with corresponding protection levels is insufficient.
According to the regulations, the new coronavirus is classified as Class A management of infectious diseases. In order to avoid contamination, testing must be done at least in a laboratory that has reached the level of biosafety.
There must be negative pressure equipment in the testing laboratory, and the airflow can only enter and cannot exit; the cleanliness, ventilation system, and disinfection and sterilization of the laboratory are all available.
If you do not have the conditions to do the test, it is likely that the virus will leak, and the laboratory will become a source of contamination.
6. The number of samples tested per day is limited. Before January 16, there was no kit in Hubei Province, and highly suspected samples needed to be sent to a nationally designated testing agency for virus isolation and nucleic acid testing. This cycle is usually 3 to 5 days.
7. According to national policy, hospitals are currently unable to directly purchase new virus detection kits, only the CDC has kits. (At present, the regulators have conditionally allowed medical institutions to carry out nucleic acid testing for new coronaviruses. But three conditions must be met at the same time: Class III A hospitals, relevant biosafety laboratories of Class II and above, and clinical gene amplification. Additional testing laboratory.)
However, usually a kit needs to go through multiple links such as research and development, production, and approval before it can be truly applied to patients, which takes 2 to 3 years.
“Today, the severe epidemic can’t stand such a long wait.” Experts are telling reporters that the State Drug Administrations have opened up a fast-track approval channel, which has quickly shortened the previous 3-5 years to about 5 days.
In addition, authorities at many locations have made it clear that for some companies that have developed and produced virus kits, they will adopt the method of first trial and then declaration, allowing first trial in medical institutions, and then reviewing according to the procedures after the epidemic is over.
So, what technologies are used in the new coronavirus detection kits that have been developed? What are the advantages and disadvantages?
Experts say that among them, the most important is the RT-PCR detection method based on the virus gene sequence. The reagents of this method are easy to implement and the detection results are accurate, but the detection conditions are relatively high. Also, professional instruments and special molecular detection experiments are required.
If the experimental conditions are not up to standard, it will lead to aerosol contamination, resulting in false positives.
The “gold standard” for the detection of new coronaviruses mainly relies on sequencing, but due to the high cost, it is difficult to use it in all sample testing.
In addition, in addition to detecting the gene sequence of the virus, rapid POCT screening can also be achieved by detecting the antigen of the virus itself or the antibody produced in the body after virus infection. Among them, colloidal gold or fluorescence chromatography is used to detect virus antigens, especially It is suitable for rapid on-site screening during large outbreaks, and does not require professional instruments or special environments.
The POCT products represented by colloidal gold immunochromatography have a short detection time (within 15 minutes), simple operation, the results can be judged by the naked eye, and rapid screening can be performed, which greatly speeds up the detection speed.
But the approach requires specificity-based antibodies, which can take months to develop and produce at the earliest.