According to the sampling survey released by the Center for Disease Control and Prevention in Erdos, Inner Mongolia, only 1.75% of the confirmed infected people are asymptomatic.

On February 30th, the Center for Disease Control and Prevention of Erdos released a sample survey of COVID-19 infection questionnaire on WeChat official account 12. The results showed that there were 27,502 residents who participated in this questionnaire survey, of whom16,562 were infected with COVID-19, and only 1.75% had no symptoms.

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Ordos CDC pointed out that this questionnaire survey shows that12,820 residents have turned negative and are in the infection period, accounting for 46.438+0% of the total number of people surveyed; There were 3742 residents who had symptoms but did not get antigen, accounting for 13.38+0% of the total number of people surveyed.

Of the 16562 people who were confirmed to be infected with COVID-19, 78.89% had fever, 68.93% had headache, 64.88% had cough and expectoration, 6 1.98% had muscle soreness and 6 1.23% had sore throat. 5 1.84% people have nasal congestion and runny nose, 4 1. 18% people have joint pain, 36.05% people have poor appetite, 25.23% people have lost their sense of taste and smell, 12.88% people have abdominal pain and diarrhea,/.

According to the news of Ordos CDC, as of February 30th, 65438, the infection rate of COVID-19 among residents who participated in this survey was 60.22%, which indicated that COVID-19 infection in Ordos was in a high epidemic stage.

It has been reported before

Why do you feel that the proportion of asymptomatic infected people around you is very small? Experts tell the reason.

The proportion of asymptomatic infected people in COVID-19 has been widely concerned. At the beginning of this month, the data released at the press conference on epidemic prevention and control in Guangzhou showed that asymptomatic infected people in Guangzhou accounted for about 90% of the total number of infected people. Recently, many experts and scholars have also expressed the view that with the weakening of the pathogenicity of Omicron and the popularization of vaccination, asymptomatic infection accounts for a higher proportion. As more and more infected people share their experiences of fighting COVID-19 with their relatives and friends, many people find that "there are light infected people around them, and few asymptomatic infected people".

Wu Hao 12, head of the expert group on community-based epidemic prevention and control in COVID-19, National Health Commission, and dean of the School of General Practice and Continuing Education of Capital Medical University, said in an interview with the Global Times reporter that the reason for this feeling is that the detection strategy and prevention and control measures have changed. In the past, it was basically nucleic acid detection, and the sensitivity of nucleic acid detection was higher than that of antigen detection. Now many people who live in isolation at home begin to use antigen testing, and many asymptomatic infected people can't be detected by antigen testing kit, resulting in the proportion of symptomatic infected people.

The previously published diagnosis and treatment plan for COVID-19 clearly pointed out that COVID-19 asymptomatic infected people were positive for nucleic acid detection, but there were no related clinical manifestations, such as fever, dry cough, fatigue, sore throat, hypoesthesia, diarrhea and other symptoms and signs that could be self-perceived or clinically recognized, and CT images had no COVID-19 imaging features. However, mild cases have positive nucleic acid detection and mild clinical manifestations, usually showing symptoms such as fever, respiratory infection, mild fatigue, generally no symptoms such as dyspnea and chest tightness, and no pneumonia in imaging.

"But now many people may think that many infected people around them have symptoms such as fever, cough and sore throat, which seems to be inconsistent with the situation that we have publicized before that there are still a large number of asymptomatic infected people. In fact, the two are not contradictory. " Wu Hao pointed out that we use "positive nucleic acid test" as the gold standard for diagnosing COVID-19. According to the ninth edition of the national COVID-19 diagnosis and treatment plan, once the CT value of nucleic acid reagent is less than 40, it is determined that the nucleic acid test is positive. Now we use antigen detection as an auxiliary detection method. Practical observation shows that, generally speaking, the CT value of nucleic acid detection of infected people is less than 28. When antigen detection is carried out, red or purple bands will be displayed at "C" and "T" of the kit, and then positive infected people can be screened through antigen detection. The difference between the two detection methods has caused many asymptomatic infected people to be positive for nucleic acid, and the antigen test will be a "healthy population". "In fact, many asymptomatic infected people with low viral load in the body cannot be detected by antigen testing. In reality, it is also found that even if the antigen test is negative, even if the nucleic acid test is positive, the drug loading is low and the infectivity is weak. "

In the ninth edition of COVID-19 prevention and control plan, it is clear for the first time that primary medical institutions can increase antigen testing for suspicious patients. With the gradual optimization of the prevention and control plan in COVID-19, the scope and frequency of nucleic acid testing are gradually decreasing, and people who need independent antigen testing are encouraged to carry out their own antigen testing at any time according to the principle of voluntary. Therefore, many people who were isolated at home began to use antigen testing to determine whether they and their families were infected with COVID-19 virus.

"If you use antigen testing, first, you feel that you are at risk of being infected, and second, you find that you have symptoms, so you start testing. In this case, there will be more symptomatic infected people because many asymptomatic infected people do not seek screening. " Wu Hao said.

Wu Hao pointed out that it is necessary to look at the adjustment of epidemic prevention and control measures more rationally. After nearly three years of scientific anti-epidemic, many people have developed good hygiene habits such as keeping a proper social distance, wearing masks and washing hands frequently. These good hygiene habits can greatly help us to avoid the spread of the virus in the future.

Regarding the adjustment and gradual optimization of epidemic prevention policies, Wu Hao said that this is by no means a simple "liberalization", let alone "lying flat", but an overall plan and balance after considering economic production activities and people's normal life. "The formulation of public health policy must be a strategy after considering all aspects. Omicron shows the characteristics of strong transmission, but relatively low pathogenicity. If traditional epidemic prevention methods are used to deal with it, the cost is unbearable. In the future, we should constantly optimize and adjust epidemic prevention policies according to the characteristics of COVID-19, take small steps and never look back. Now we must seize the time to make preparations, including rapidly promoting vaccination for the elderly, strengthening the reserve of medical materials, strengthening the training of diagnosis and treatment ability of grassroots medical personnel, focusing on prevention and treatment of COVID-19 in rural areas and prevention and treatment of children, optimizing measures according to the characteristics of virus variation, increasing science popularization, responding to public concerns and doubts in a timely manner, eliminating panic, preventing medical runs, and using limited medical resources on the' cutting edge' to reduce the occurrence of severe cases and deaths. "