People ’s Daily Overseas Edition April 10 news that recently, asymptomatic people with new coronary pneumonia have entered people ’s vision, and many people may even be nervous. In the prevention and control of the new coronary pneumonia epidemic, asymptomatic infections have become another problem faced by international and domestic scholars. According to the National Health and Health Commission, as of 24:00 on April 7, 2020, 31 provinces (autonomous regions and municipalities) and the Xinjiang Production and Construction Corps reported 137 new cases of asymptomatic infections. So, what is an asymptomatic infected person and how to identify it? How to protect it? The newspaper today explained the relevant knowledge of asymptomatic infection.


How to define asymptomatic infected persons?

The full name of “asymptomatic infected person” is “asymptomatic infected person of New Coronavirus”, which refers to the etiological detection of New Coronavirus without clinical symptoms but respiratory specimens Those who are positive.

Asymptomatic infections can be divided into two situations: one is that the infected person has a positive nucleic acid test, and after 14 days of incubation, there is no self-perception or The clinically recognized symptoms and signs are always asymptomatic; the second is that the infected person’s nucleic acid test is positive, there are no self-perceived or clinically recognizable symptoms and signs when sampling, but then there is a clinical manifestation that is in the incubation period “Asymptomatic infection” status.


Is the asymptomatic infected person contagious?

Asymptomatic people are infectious. However, the length and strength of the infection period have yet to be determined. Many people worry that “asymptomatic infected people” will become a new source of infection, so, will it?

Some experts believe that in view of the fact that asymptomatic infected respiratory specimens can detect pathogenic nucleic acid, but due to the absence of clinical symptoms such as coughing and sneezing, the pathogen is excreted from the body and causes the opportunity for transmission Relatively fewer cases are diagnosed. In addition, there was a recent report in the “England Medical Journal” that an infected person never developed symptoms, but the amount of virus released was comparable to those who developed symptoms. Therefore, some scientists have speculated that some infected people “are highly contagious when the symptoms are mild or asymptomatic.” However, it should be emphasized that the size of patients with similar conditions is still unclear.

In short, the length of infection, the strength, and the mode of transmission of asymptomatic patients are still to be determined. Do n’t let your guard down!


What are the risks of asymptomatic infection?

Asymptomatic people are at risk of transmission. One is the concealment of transmission. Asymptomatic infections do not have any obvious symptoms and signs, so it is difficult to be found in the population, and the resulting transmission is also difficult to prevent.

The second is the subjectivity of the symptoms. People with mild or atypical symptoms may think that they have not been infected with the new coronavirus and do not take the initiative to go to a medical institution for treatment, which is difficult to be found in daily diagnosis and treatment.

The third is the limitation of discovery. Due to the detection window period, it is difficult to find all asymptomatic patients using nucleic acid detection and serological detection methods.

Zhang Wenhong, director of the Department of Infection, Huashan Hospital Affiliated to Fudan University, said that asymptomatic infections are an important type of surveillance target for China to enter the “second half” of epidemic prevention and control. The patient has a strong immunity and can be free from the disease within 14 days after being infected with the virus. The virus has been in the body for more than three weeks and has the possibility of infection. If it is not detected and isolated in time, there is a hidden danger of community transmission.

Jiang Qingwu, former dean of the School of Public Health of Fudan University, pointed out that many infectious diseases have hidden infections, but their proportions are different in different infectious diseases.

As early as February 17, the large-scale rheological paper published by the Epidemiology Group of the Chinese Center for Disease Control in the Chinese Journal of Epidemiology mentioned, As of February 11, the Chinese Center for Disease Control and Prevention received a total of 72,314 cases reported domestically, including 889 cases of asymptomatic infections, accounting for about 1.2%.

At the same time, some experts pointed out that in fact, clinical observation will find that most people will eventually show symptoms, and there are very few patients who are truly latent infections, probably 1 %.

A report from a Japanese research team (the research paper was published in the “Eurosurveillance” magazine on March 12) conducted 634 cases of new pneumonia on the Diamond Princess Statistical model analysis estimated that the proportion of asymptomatic infections was 17.9%.

Zhang Wenhong ’s team pointed out that taking part of the current research as an example, among the people infected with the new coronavirus, the proportion of asymptomatic infections is about 18% -31%. However, some patients only have very slightSymptoms are not necessarily discovered during isolation observation, and are often considered asymptomatic.

What does this data mean? Assuming that 10 people are exposed to the virus, 6-8 people may eventually get sick, 2-4 people will never get sick or the symptoms are very mild, the latter is the so-called asymptomatic infection.


How to identify people with asymptomatic infection?

The data shows that there are 4 main ways to find asymptomatic infections:

Active detection during medical observation of close contacts of new coronary pneumonia cases;

Second is the active detection carried out in the investigation of cluster epidemics;

The third is the active detection of the exposed population during the tracking of the source of infection of new coronary pneumonia cases; Active detection of personnel in the region ’s travel history and residence history.


How do people with asymptomatic infections develop?

Asymptomatic infected persons are those who are positive by nucleic acid test but do not have any clinical symptoms. All asymptomatic infected persons must have had a history of contact with the diagnosed patient, or have been to the epidemic area. For areas where epidemics have occurred but confirmed cases have been cleared for more than two weeks, there will be no sudden asymptomatic infections for no reason.

Our current measures should be able to detect and control asymptomatic infections in a timely manner. The asymptomatic infections are unlikely to cause epidemics and will not cause society Level of diffusion.


How to prevent and manage asymptomatic infected persons?

First, perfect the prevention and control plan to curb the spread of new epidemics that may form.

The second is to increase screening and monitoring. After finding asymptomatic infected persons, carry out an epidemiological investigation in a timely manner, identify the source, and publicly and transparently release information.

The third is to strengthen management and treatment. Once an asymptomatic infected person is found, it is necessary to immediately follow the requirements of “four early” (early detection, early report, early isolation, early treatment), strictly concentrate isolation and medical management, and implement isolated medical observation for close contacts. Symptoms appear during quarantine and are immediately transferred to a designated medical institution for treatment.

Fourth is to strengthen group defense and group control.


How to do personal protection?

The public should strengthen self-protection and health and civilization awareness, strengthen environmental hygiene and personal hygiene protection, develop hand washing, wear masks, pay attention to hand hygiene, one Rice noodles, window ventilation, cleaning and disinfection, meal sharing system, reducing the number of people to gather places and wearing scientific masks and other healthy lifestyles when sick.

The patriotic health campaign should be widely carried out, spreading health knowledge to every family and individual in the spirit of protecting themselves and the health of others, and forming a good Hygienic habits and a civilized and healthy, green and environmentally-friendly lifestyle improve mental health and health literacy.

Keep yourself healthy. Strengthen exercise, eat light and regular, and ensure adequate sleep. If you feel stressed, learn some decompression methods. If you suffer from chronic diseases, please take medicine as much as possible.

If the individual ’s nucleic acid test is positive, there is no need to panic. Actively cooperate with medical and health institutions to do health monitoring and quarantine medical observation. Report fever and cough and other symptoms in time. Accept standardized diagnosis and treatment in medical institutions.

(Originally entitled “What’s the problem with asymptomatic infection?”)