Multiple Rounds Of Nucleic Acid Detection To Break The "Latent Period" And "Occult" Of Virus

Intern Peng Xinyi reports from Beijing

According to the data of the National Health Commission, there were 62 new local cases (40 in Jiangsu, 9 in Hunan, 3 in Beijing, 3 in Shandong, 3 in Henan, 3 in Yunnan and 1 in Hubei) between 0 and 24 August 4. So far, the transmission chain of the epidemic situation in Nanjing airport has continued to extend, with nearly 560 infected people, which has spilled out to many provinces and Macao Special Administrative Region, showing a multi center spread trend.

Recently, Feng Zijian, a researcher at the center for Disease Control and prevention of China, said in an interview with the 21st century economic reporter that the "delta" mutant strain has significantly enhanced its infectivity and transmission capacity, and its transmission capacity has increased by 100% compared with the early epidemic strains. In addition, the mutant virus can reduce the neutralizing activity of neutralizing antibodies induced by previous infections and existing vaccines.

The reporter of 21st century economic report learned that affected by sporadic cases, multiple rounds of nucleic acid detection were carried out in many places. The fifth round of nucleic acid detection is about to be carried out in Nanjing, the third round in Yangzhou, the second round in Zhengzhou, Tianjin, Xiamen, Chongqing, Sichuan and some other areas have completed the nucleic acid detection, and Zhuhai, Yantai and other places have also started the whole staff nucleic acid testing.

Why multiple rounds of nucleic acid testing? In this regard, Liu Ping, founder of boassez, told reporters of the 21st century economic report that the new coronavirus has a certain incubation period and concealment. In addition, the problems of sampling and viral load may lead to the failure to screen out some patients with early infection through a single nucleic acid test. Therefore, multiple rounds of screening is necessary“ At present, the production capacity of each nucleic acid detection reagent manufacturer is sufficient, so there is no problem in the supply of nucleic acid detection related equipment and reagents in all provinces and cities. "

Carry out multiple rounds of nucleic acid detection for all staff in multiple places

The reporter of 21st century economic report learned that affected by sporadic cases, multiple rounds of nucleic acid detection were carried out in many places.

On August 3, Zhangjiajie City has completed two rounds of nucleic acid testing, and has started the third round of national nucleic acid testing on August 4.

At the same time, Yantai City started the whole staff nucleic acid detection. A total of 2.265 million people were involved in the first round of nucleic acid testing in Yantai's main urban area. As of 2:00 p.m. on the 4th, 1.569 million people had been sampled, accounting for 69.3%, and 239000 people had been reported as negative. After that, the Yantai municipal Party Committee headquarters comprehensively studied and judged the new cases and activity tracks, and decided to carry out the whole area and all staff nucleic acid detection on the basis of the implementation of the whole staff nucleic acid detection in the central urban area.

On the evening of August 4, 11.18 million people were sampled for the first round of nucleic acid detection in Zhengzhou, and all of them completed the detection task. At present, in addition to the initial single sampling and single test found out 2 infected people, the first round of full staff nucleic acid testing has screened out 99 confirmed cases and asymptomatic infection. On August 5, Zhengzhou will carry out the second round of nucleic acid testing.

On August 5, Wang Jinsong, deputy director of Yangzhou Municipal Health Commission, said at the seventh press conference on epidemic prevention and control that in the two rounds of large-scale nucleic acid testing that had been completed in Yangzhou, more than 3.2 million person times of nucleic acid sampling were completed, and 26 people were found to be positive. On the same day, the third round of large-scale nucleic acid detection was launched in the main urban area of Yangzhou.

At present, there have been four rounds of nucleic acid testing and screening in Nanjing. The first three rounds are full-time nucleic acid testing and screening, and the fourth round is nucleic acid testing and screening in some regions. In the fourth round of nucleic acid detection, 5.675 million people have been found, and 7 cases have been confirmed. At a press conference held on August 5, Yang Dashuo, deputy director of the Nanjing Municipal Health Commission, introduced that according to the four more principles of "more accurate classification, more emphasis, more efficiency and more quality assurance", the Nanjing epidemic prevention headquarters determined the scope of the fifth round of nucleic acid detection, and designated the smallest area to the community and village.

Why multiple rounds of nucleic acid testing? Bao Zhaojun, director and chief physician of Jiangsu Provincial Center for Disease Control and prevention, said in an interview with the media that the new coronavirus is characterized by a certain incubation period and concealment. When nucleic acid is detected, if the concentration of the virus in the body is not enough and below the detection limit, it may not be detected; There is also the possibility that different people have different sampling methods and fail to collect the appropriate parts, which may lead to missed detection; Finally, there may be a small number of infected people have clearance phenomenon, and sampling is only a point in time, it may cause missed detection.

Nucleic acid detection ability is the key

Recently, Feng Zijian, in an exclusive interview with the 21st century economic reporter, said that the "delta" mutant strain has significantly enhanced its infectivity and transmission capacity, and its transmission capacity has increased by 100% compared with the early epidemic strains.

In fact, in the "race" with viruses, nucleic acid detection ability is the key to win.

Under the demand of large-scale nucleic acid detection, related nucleic acid detection reagent manufacturers have been widely concerned. Recently, some investors asked Daan gene (002030. SZ) about the production situation on the investor interaction platform. Daan gene said that at present, the standard capacity of the company's new crown nucleic acid detection reagent is about 1 million copies / day, and the company will continue to start sufficient production capacity to fully guarantee the market supply.

Liu Ping told the 21st century economic report that at present, the production capacity of each nucleic acid detection reagent manufacturer is sufficient, so there is no problem in the supply of nucleic acid detection related equipment and reagents in all provinces and cities.

Deng Zhongping, deputy general manager of Shengxiang biology, also said in an interview with the media that since last year's anti epidemic, the company's production capacity has been greatly improved. At present, the company's new crown nucleic acid detection reagent production capacity can reach 3 million copies / day.

In addition, in order to further improve the efficiency of new crown nucleic acid detection, local governments and related enterprises have launched relevant nucleic acid detection laboratories.

Wuxi health commission has launched the "fire eye" laboratory project. It is reported that the "fire eye" laboratory can improve the city's daily inspection and measurement of 30000 single tubes (one tube has 10 copies), and the city's maximum detection capacity can reach 330000 single tubes per day, which can achieve the goal of more than 8 million people's nucleic acid detection in three days.

The "Falcon" gas film laboratory has also been put into operation for the first time in Nanjing, Jiangsu Province. It is understood that the daily detection capacity of six groups of gas membrane laboratories built in the Youth Olympic sports park can exceed 180000 tubes. If the sampling method of 10 mixed 1 is adopted, the laboratory can help Nanjing complete the nucleic acid detection of 1.8 million people in a day.

In addition to the sufficient production capacity of nucleic acid detection reagents, the number of nucleic acid detection patents in China is also growing. According to the data of smart bud, the number of patent applications for nucleic acid detection in China has increased in the past 10 years, with more than 2000 patents applied for nucleic acid detection related technologies, including more than 500 valid patents. In 2020, due to the outbreak of the epidemic, the number of patent applications for related technologies will "double" compared with the previous year. Tsinghua University, Southeast University, Haikang life, Wuhan Zhongzhi and other companies and colleges are the main applicants for relevant technologies in China. From the distribution area, Jiangsu, Guangdong, Beijing, Shanghai, Zhejiang and other economically developed areas are more provinces and cities of nucleic acid detection.

Among them, by the end of 2020, Rendu biology has applied for 43 invention patents at home and abroad, including 40 domestic patents and 25 authorized patents; 3 international patents and 2 authorized patents. Rendu biology has also rapidly developed the autosat full-automatic new coronavirus 2019 ncov nucleic acid detection platform. Compared with DNA molecular diagnosis technology (PCR), sat technology has the characteristics of high sensitivity, strong specificity, low cross contamination, good biological safety and easy to realize automatic high-throughput detection. Compared with the manual or semi-automatic detection mode of nucleic acid detection products that have been put on the market at present, the overall solution of rendo biology, combined with the autosat full-automatic nucleic acid detection and analysis system previously launched, can realize assembly line operation, report the first result in 90 minutes, report one result in 2 minutes on average, and complete 200 tests in 8 hours.