About the scope and frequency of nucleic acid detection, the construction of 15-minute nucleic acid sampling circle … authoritative response!

The State Council Joint Prevention and Control Mechanism held a press conference in Beijing on June 9th to introduce the situation of nucleic acid detection and epidemic prevention and control. Let’s look at it together-

If there is no epidemic situation and no import risk, nucleic acid inspection should not be the norm.

After the outbreak of cluster epidemic, according to the needs of epidemic prevention and control, we should scientifically determine the strategy of nucleic acid detection, delimit the scope and frequency of nucleic acid detection, avoid blindly expanding the scope of nucleic acid detection for all staff, and carry out nucleic acid detection in turn according to the risk level from high to low. The first nucleic acid screening should be completed in the sealed control area within 24 hours, and the first full-time nucleic acid screening should be completed in the control area within 48 hours. That is to say, after the outbreak, the personnel, scope and frequency of nucleic acid testing must be arranged as a whole according to the needs of epidemic prevention and control. People in medium and high-risk areas, sealed control areas and control areas are not allowed to go out, but if it is really necessary to travel in low-risk areas and prevention areas where the epidemic occurs, a 48-hour negative nucleic acid test certificate is required. All localities can make adjustments according to the needs of epidemic prevention and control.

If there is no epidemic situation and there is no risk of import, nucleic acid inspection should not become a normal state.

The 15-minute nucleic acid sampling circle should be built according to the time and situation.

In the prevention and control of normalized epidemic situation, such as port cities, provincial capital cities and cities with a population of 10 million, because of the high risk of epidemic situation input, it is beneficial to provide more convenient and convenient nucleic acid testing services for people who should and want to complete the inspection. It is conducive to improving the sensitivity of epidemic monitoring and early warning and building a system for early warning and discovery of epidemic situation; It is also conducive to discovering potential risks earlier, implementing prevention and control measures faster, and avoiding large-scale and explosive clustering epidemics. In particular, it is important to emphasize that the 15-minute nucleic acid sampling circle is not required to be established in all cities, but mainly concentrated in large cities with high risk of epidemic import, especially with large population. Whether to build a 15-minute nucleic acid sampling circle and the frequency of our detection are mainly based on the occurrence and development of the local epidemic situation and the needs of prevention and control work, and should be determined according to the situation and the situation, and it is not possible to make a "one size fits all".

Nucleic acid detection is the "gold standard" of diagnosis, and virus variation has no effect on the detection ability of nucleic acid detection.

As for nucleic acid detection, it is a mature and international laboratory diagnostic method. In the past, we mainly relied on culture to detect the pathogen of virus, and we identified it by dyeing, morphological observation, biochemical test, immune test and other methods. The virus was cultivated for a long time, and some pathogens in the laboratory were difficult to cultivate. Later, we had a nucleic acid detection method. The nucleic acid detection method has high sensitivity and specificity can reach 100% in methodology. That is to say, the positive result of nucleic acid detection is equivalent to the result of pathogen culture and becomes the "gold standard" of diagnosis. Not only do we do COVID-19’s viruses, but also common pathogens, such as hepatitis B virus and HIV, can be diagnosed by nucleic acid detection and monitored for treatment.

We do nucleic acid detection in Covid-19, and the nucleic acid detection reagents used are aimed at the double-target or triple-target genes in COVID-19. There is basically no possibility that the virus mutation will mutate in two or three target genes at the same time, so the virus mutation has no influence on the detection ability of nucleic acid detection.

Positive nucleic acid detection in environmental samples does not mean that there is a live virus.

The positive detection of nucleic acid in environmental samples does not mean that there must be a live virus in environmental samples. If there is a live virus, it is necessary to do cell virus isolation or sensitive mice to isolate the virus to determine whether there is a live virus. Because both dead virus and live virus are in environmental samples, or the inactivated COVID-19 vaccine we are playing now, it contains nucleic acid, which can be detected as positive by nucleic acid detection, so the detection of nucleic acid positive does not mean that it has a live virus, so it should be comprehensively judged.

There is no need for frequent nucleic acid testing in low-risk areas and low-risk people.

There is no need for frequent nucleic acid testing in low-risk areas and low-risk people, such as long-term family members. The focus of nucleic acid testing should be on high-risk people and staff in high-risk positions, as well as areas with epidemic situation.

It is necessary to publish the information of nucleic acid sampling points in time, feedback and update the test results in time.

To publish the information of sampling points in time, we can publish the sampling points to the public through official websites, clients, WeChat WeChat official account and public service applets, so that the public can choose the nearest points for nucleic acid sampling. In addition, we also guide local governments to constantly establish and improve electronic maps and update them in time to facilitate people’s inquiries and sampling nearby.

It is necessary to feed back and update the test results in time. After the testing organization completes the test, the relevant departments should synchronize the test results to the health code and other platforms in time, so that the public can find their own test results as soon as possible.

Nucleic acid detection sampling swab belongs to medical devices, not cotton swabs, and is non-toxic and harmless.

The sampling swab looks like a cotton swab, but it is not a cotton swab. It is made of polyester or nylon fiber, which is similar to the toothbrush in our daily life. The bristles of the toothbrush are also nylon, but in the process of making our sampling swab, millions of tiny fibers are vertically and evenly covered on the handle end of the swab. When we are sampling, we brush our teeth like a toothbrush, but it brushes the posterior pharyngeal wall in our mouth to take cells, and then puts the sampling swab into the sampling tube. Because it uses nylon and polyester, it is easy to take it off into the preservation solution, and then the relevant tests are carried out in the laboratory.

Sampling swab belongs to medical devices, its production environment and requirements are very strict, and there are also relevant standards for quality supervision. The most basic standard of one of our products is non-toxic and harmless, and harmful substances will not be produced in the production process of sampling swab.

For large-scale population screening, oropharyngeal swabs are generally used.

Samples include samples of lower respiratory tract, such as sputum, and samples of upper respiratory tract, such as nasopharyngeal swab and oropharyngeal swab. Among these swabs, the sputum virus content is the highest and the positive detection rate is the highest, followed by nasopharyngeal swabs and oropharyngeal swabs. As an infected person in Covid-19, dry cough was the main symptom in the early days, and sputum is not saliva, so it is difficult to obtain. The collection of nasopharyngeal swab requires a high level of operation of the sampler, and the sampling process is slow. Although the positive rate is higher than that of pharyngeal swab, it is generally not used for screening most people, but can be used for sampling isolated people. The sampling of oropharyngeal swab is relatively simple and fast, so we usually use oropharyngeal swab in large-scale population screening, although its detection rate is not as good as that of nasopharyngeal swab. As an anal swab, we don’t recommend it. Considering the discomfort of the taker and the low positive detection rate of anal swab, we don’t recommend sampling with anal swab.

There are three situations in which nucleic acid detection is negative for many times and then positive.

Nucleic acid test is negative for many times in a row, and finally it appears positive. Most people will not have it, but it has happened. It should be in these three situations: in the first case, this person was not infected at first, but infected at a later time, and then the test was positive after infection. Also, when we were in the incubation period, our test was not detected, and the test was positive after the onset. The third aspect, as mentioned above, is that although the virus was present at the beginning, its load could not reach the lower detection limit, and it was not detected at this time, but it was detected as soon as the load was high.

Those who take illegal and compulsory measures for nucleic acid detection will be required to rectify and correct in time.

Call on the masses to abide by the relevant provisions and requirements of epidemic prevention and control in accordance with the law, actively cooperate with the development of nucleic acid testing, fulfill their personal prevention and control obligations, and jointly promote the formation of a good social atmosphere for mass prevention and control.

For regions, units and individuals who take illegal and compulsory measures, the joint prevention and control mechanism of the State Council will require the relevant places to rectify and correct in time, and the media friends are also welcome to supervise.