On March 20, a report from the international top academic journal Nature stated that preliminary research showed that hidden cases of new crown virus may account for about 60%of all infection cases.

The main evidence of the conclusion is the paper published by the Public Health College of Huazhong University of Science and Technology on March 6th on March 6th.The paper analyzed the legal infectious disease report system of the Wuhan Health and Health Commission, as of 25961 laboratory diagnosis of new crown pneumonia case data on February 18.On the basis of these data, the Gangtangchun team estimates through modeling analysis that at least 59%of the infection cases in Wuhan are not found, which may include asymptomatic and symptoms of minor.The thesis believes that an estimate of unlimited cases is of great significance for continuous monitoring and infection.

Announced asymptomatic cases account for geometry

Earlier, a number of studies at home and abroad have shown that the proportion of asymptomatic infections may be much higher than expected.Asymptomatic infections include hidden patients and lurking patients who have never occurred.The so -called hidden patients refer to the pathogen that only causes the body to produce specific immune response, but does not cause or only cause minor tissue damage.It can be found through laboratory testing.

The WHO's joint inspection report released by the China-World Health Organization COVID-19, which was released after the inspection of China-World Health Organization, which was inspected in China from February 16th to 24th, was included in the risk factors of asymptomatic infection, and said that there were already existing existenceAsymptomatic infection reports, but most of the cases of non -symptoms are subsequently reported in reporting.The report pointed out that the proportion of true asymptomatic infections is not clear, but it is relatively rare, and it is not the main driving factor of propagation.But the latest statistics and modeling show that the proportion of asymptomatic infected people may be greatly underestimated.

According to the global monitoring of the 2019 coronary virus caused by the people issued by the WHO infected with the 2019 new coronary virus, no matter whether there is a clinical signs and symptoms, those who are diagnosed with the infected new coronary virus are diagnosed.

But China has different diagnosis standards.In the new type of coronary virus pneumonia (fourth edition) released by the National Health and Health Commission, nucleic acid testing positive cases is divided into two types: confirmed cases and asymptomatic infections.List.

In the fifth edition of the updated diagnosis and treatment plan on February 5, for the first time, it is clearly stated that those with no symptoms may also become a source of infection.

South Korea uses the definition of confirmed cases of WHO.Zheng Yinjing, director of the South Korean Centers for Disease Control and Prevention, said at a press conference on March 16 that the current asymptomatic cases of South Korea are significantly higher than that of other countries, which may be due to extensive testing.As of March 18, South Korea has conducted nearly 300,000 tests.In the asymptomatic cases reported by the Korean Centers for Disease Control and Prevention, more than 20%of infection cases were still asymptomatic before discharge.

On February 13, the international infectious disease magazine received a dissertation from Japanese experts such as Hokosun University of Hokkaido University of Hokkaido.This paper studied the 565 Japanese citizens evacuated from Wuhan chartered machine. The results found that there were 13 infections from the evacuator, and 4 of them were asymptomatic infected with a proportion of 30.8%.In this regard, the Xicun team estimates that among the infected people in the new crown virus, less than half of the infected people may not be asymptomatic.

The sample of the Diamond Princess Cruise may be closer to the actual situation.On March 12, George Asia State University mathematical epidemiologist Jero Dardo Middot; Professor Cowier's monitoring in Europe showed that as of February 20, 634 people on board were positive.The proportion of symptoms infection was 17.9%.

Recent studies have shown that those with asymptomatic or mild infections may be highly contagious.On March 8th, a research group released by a German research team in the pre -printed platform of medical papers MEDRXIV showed that when some new coronary virus patients had mild symptoms in the early stage of the onset, the level of virus in the throat swab was higher.

The paper published by the Guangdong Provincial Center for Disease Control and Prevention in New England Medical Magazine pointed out that 17 patients found in Guangdong Province detected higher virus loads shortly after the symptoms appeared.The virus load is similar to that of patients with symptoms, which indicates the potential of asymptomatic or mild patients.

The sampling survey needs to be carried out urgently

Ji Tangchun told China News Weekly that 59%of the infected cases that may not be found may be predicted based on the most conservative model and did not conduct actual epidemiological investigations based on the most conservative model.

Science is very rigorous, and possible things cannot be said to be sure.The space design of the model is not perfect, so there must be a large sample to make actual sampling in order to get the differences in regional differences and the number of potential hidden infections.Wu Tangchun said.In this regard, as early as mid -February, he and Academician Wang Chen had suggested to the Hubei Provincial Epidemic Prevention Headquarters and relevant departments to conduct epidemiological sampling examinations.

Anymal -free infection, including patients with incubation periods that have not occurred during testing, and hidden infections who never cause disease after infection.Professor Jiang Qingwu, the former dean of the School of Public Health of Fudan University and a member of the New Crown Pneumonia Prevention and Control Expert Group of the Chinese Association of Prevention Medicine, said that many infectious diseases have hidden infections, and at the same time, some hidden infections will also become a source of infection.Because the hidden infection of poisoning will not be isolate, and the scope of activity is large, it is even more harmful.Under the current circumstances, it is a way to judge hidden infections through models, but because the model assumptions have many conditions, they should not be advocated.He reminded that infected in Wuhan cannot over -trust the model, and must answer the question of hidden infection through actual surveys.

Jiang Qingwu explained that after the human body is infected with the virus, most patients will produce antibodies. This is the evidence that the virus exists in the human body.Therefore, antibody testing is a good way to confirm the hidden infection of new infectious diseases.In Wuhan area, it is necessary to send professional epidemiological investigators to conduct antibody epidemiological sampling surveys.Specifically, the survey can be divided into two parts, and some of the high -exposed people such as close contact with the close contact with the confirmed cases have been excluded before, and the other part is targeted at the general population.

Jiang Qingwu said that theoretically, the larger the sample sample size, the better.The specific epidemiological survey requires a series of conditions to determine the number of samples.According to the current number of accumulated diagnostic people in Wuhan, at least the sample survey of more than 2,500 people must be performed in order to reflect the overall situation.

Jiang Qingwu pointed out that the data of hidden infections is an important indicator of future decision -making, which is related to whether the new crown pneumonia will be reunited, and once the soil comes, how to deal with it.Relevant departments can refer to the results of the investigation and make decisions in the next stage.

In Wuhan area, antibody sampling surveys are fully operable.This is also what Wuhan should be completed, because there are no other areas except Wuhan.Such a survey is of great significance to Wuhan and the country. As long as the possibility is possible, it should be done by selling iron even if it is smashed.Jiang Qingwu emphasized.

A survey of serum antibody epidemic disease is the most critical scientific evidence to grasp the law of the disease. It is the most important basis for making scientific decision -making on further prevention and control measures.To do a good job in survey of nucleic acid and serum antibody epidemiological diseases, it is a key task that must be completed in the future and is extremely urgent to complete scientific prevention and control.The importance of this survey should be said that it will not be able to repeat, which will directly affect the prevention and control strategy and measures.

Wu Tangchun repeatedly emphasized that for China and the world, the problem of hidden infection is the prevention and control of the epidemic.A very important scientific issue should be paid great attention.