(Fighting against New Coronary Pneumonia) Why are there so many “asymptomatic” epidemics in this round of epidemics at the turn of winter and spring?
China News Agency, Beijing, March 11 Question: Why are there so many “asymptomatic” epidemics in this round of epidemics at the turn of winter and spring?
China News Agency reporter Li Chun
According to the epidemic information reported by the National Health Commission of China on the 11th, there were 397 new confirmed cases of new coronary pneumonia in mainland China on the 10th, and the number of local asymptomatic infections reached 703. The number of new infections in a single day exceeded 1,000, reaching 1,100.
The epidemic situation in mainland China has recently shown a trend of spreading and growing rapidly in many places. From the 4th to the 9th of this month, the number of newly confirmed local cases in a single day increased from 102 to 402. The number of new local infections in a single day has exceeded 500 for 5 consecutive days, and it exceeded 1,000 on the 10th. Since March, 23 provinces (autonomous regions and municipalities) including Jilin, Shandong, Tianjin, Guangdong, and Inner Mongolia have reported locally confirmed cases.
On the evening of March 10, in a community in Xiqing District, Tianjin, people conducted nucleic acid tests.Photo by China News Agency reporter Tong Yu
As of 12:00 on March 11, there were 11 high-risk areas and 163 medium-risk areas in mainland China. Observing the epidemic that occurred at the turn of winter and spring, the obvious feature is the large number of asymptomatic infections. Since March 6, there have been more than 300 new asymptomatic infections in mainland China in a single day, and the 703 cases on the 10th have reached a recent high.
Taking March 9 as an example, there were 4 new local confirmed cases in Shanghai, and the number of asymptomatic infections far exceeded this number, reaching 76. Shandong Province reported 66 new local cases, nearly double the number of asymptomatic infections, reaching 112. There were 179 new asymptomatic infections in Jilin Province, which was also more than the number of newly confirmed cases (165) that day.
Why are there so many asymptomatic infections in this round of epidemics? According to Wu Jinglei, director of the Shanghai Municipal Health Commission, this is related to the characteristics of the Omicron variant.
At present, more than 100 countries around the world have found cases of Omicron infection, and this strain has become the main variant of the global epidemic. Since January this year, local clusters of outbreaks caused by the Omicron variant have also occurred in Tianjin, Anyang, Henan, Baise, Guangxi and other places. In recent epidemics, mutants of Omicron have also been found in Jiangsu, Jilin, Gansu and other places.
Studies have shown that the transmission ability of the Omicron variant is about twice that of the delta variant, and it is more likely to cause human infection and human transmission. The symptoms of infected people are also not typical, lack of specific manifestations, and the virus transmission process is more insidious. The types of confirmed cases are mainly mild and common, with relatively mild symptoms.
Another reason is mass immunization. Up to now, more than 3.17 billion doses of the new coronavirus vaccine have been reported in mainland China, with an overall vaccination rate of over 87%. With improved vaccine coverage and enhanced immunity, the symptoms after infection are relatively inconspicuous, and may even be asymptomatic.
In addition, asymptomatic infections accounted for a large proportion in this round of the epidemic, which is also related to early detection and control. According to Jiang Fachun, deputy director of the Qingdao Center for Disease Control and Prevention, rapid screening and rapid detection by disease control personnel have enabled some early infected people to be detected before they show symptoms.
This is inseparable from the enhancement of detection capabilities. At an official press conference in mid-February, Guo Yanhong, an inspector of the National Health and Medical Commission’s Medical Administration and Hospital Administration Bureau, said that as of that time, 12,277 institutions across the country had been able to carry out nucleic acid testing for the new coronavirus, with a total of 45.55 million people tested in a single tube. servings/day. If the 10-in-1 or 20-in-1 mixed sample detection method is adopted, the detection capability and efficiency will be further improved.
Residents wait in the community for medical staff to conduct nucleic acid testing and sampling.Photo by Yin Liqin
Wang Zhigang, Minister of Science and Technology of China, also said recently that the nucleic acid detection of the new coronavirus can complete sample detection within 30 minutes at the fastest, and an integrated detection system can detect 200,000 samples a day, greatly improving the detection capacity.
With the improvement of the efficiency of large-scale nucleic acid detection, more asymptomatic infections are detected early in active screening. Talking about how to achieve precise prevention and control and timely detection of positive cases, Lu Jiahai, director of the Key Laboratory of Quality Monitoring and Evaluation of Vaccines and Biological Products of the State Drug Administration and a professor at the School of Public Health of Sun Yat-Sen University, suggested that the sensitivity of nucleic acid detection should be improved first and the nucleic acid detection speed should be accelerated. Detection speed.
Measures such as epidemiological tracking, large-scale nucleic acid testing, centralized isolation, and partitioned and classified management and control are the key links to achieve “dynamic clearing”. The turn of winter and spring is a period of high incidence of respiratory diseases. Many experts have recently pointed out that in response to the challenges of epidemic prevention and control, it is necessary to adhere to the “dynamic clearing” strategy and measures.
Dong Xiaoping, chief expert of virology at the Chinese Center for Disease Control and Prevention, said in an interview with China News Agency a few days ago that “dynamic clearing” is an epidemic prevention and control method that has been explored for a long time and is suitable for the current situation in China.
Zhang Wenhong, director of the National Center for Infectious Diseases Medicine and director of the Department of Infectious Diseases of Huashan Hospital Affiliated to Fudan University, also pointed out in a long post on Weibo recently that as the anti-epidemic entered the deep water area, the strategy of “dynamic clearing” has been more clearly implemented. The next stage of work should be to strive for scientific and accurate prevention and control work, and strive to take optimal prevention and control measures in all aspects of normalized prevention and control and epidemic disposal, so as to achieve the best prevention and control with the smallest prevention and control cost. control effect. (over)Return to Sohu, see more
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