Recently, people with asymptomatic infection with the new coronavirus pneumonia have attracted widespread attention, and many people may even get nervous.

In the prevention and control of the new coronavirus pneumonia epidemic, asymptomatic infections have become another problem faced by international and domestic scholars. 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 an asymptomatic infection?

Asymptomatic infection refers to those who have no clinical symptoms but who have positive pathogenic tests for new coronavirus in the respiratory tract and other specimens.

Asymptomatic infections can be divided into two situations:

The first is that the infected person has a positive nucleic acid test. After the 14-day incubation period, there are no symptoms and signs that can be self-perceived or clinically recognized, and it is always asymptomatic;

The second is that the nucleic acid test of the infected person is positive, and there are no self-perceived or clinically recognizable symptoms and signs when sampling, but then there is a certain clinical manifestation, that is, a latent period of "asymptomatic infection".

Will they infect others?

Asymptomatic infections are contagious. 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 acids, due to the absence of clinical symptoms such as coughing and sneezing, the chance of pathogens being excreted from the body and causing transmission is relatively less than that of confirmed cases.

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. Don’t let your guard down!

What are the risks of asymptomatic infection?

People with asymptomatic infection 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 the 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 at 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, because these patients have strong immunity and can be infected within 14 days after infection No illness.

The virus has existed in its body for more than three weeks and has the possibility of infection. If it is not discovered 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 epidemiology group of the Chinese Center for Disease Control and Prevention published a large-scale essay in the "Chinese Journal of Epidemiology" mentioned that as of February 11, the Chinese Center for Disease Control has received a total of domestic reports There are 72314 cases, including 889 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. There are very few patients who are truly latent infections, about 1%.

A report from a Japanese research group (the research paper was published in the journal "Eurosurveillance" on March 12) analyzed 634 cases of new coronavirus pneumonia on the Diamond Princess cruise ship and estimated the proportion of asymptomatic infections to be 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 mild symptoms, which may not be 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 four main ways to find asymptomatic infections:

First, active detection during close medical observation of new coronavirus pneumonia cases;

The second is the active detection carried out in the investigation of cluster epidemic situation;

The third is the active detection of the exposed population during the tracking of the source of infection of new coronavirus pneumonia cases;

The fourth is the active detection of the travel history and residence history of some areas where new coronavirus pneumonia cases continue to spread.

How does an asymptomatic infection occur?

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 said to be able to detect and control asymptomatic infections in a timely manner. It is very unlikely that asymptomatic infections will cause epidemics and will not cause proliferation at the social level.

How to prevent and control the asymptomatic infected persons?

One is to 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.

The fourth is to strengthen group prevention and control.

How to do personal protection?

The public should strengthen self-protection, health and civilization awareness, strengthen environmental hygiene and personal hygiene protection, develop hand washing, wear masks, pay attention to hand hygiene, one-meter noodles, window ventilation, cleaning and disinfection, meal sharing system, and reduce the number of people gathering places when sick And scientifically wear masks and other healthy lifestyle behaviors.

To conduct extensive patriotic health campaigns, spread the knowledge of health to every family and individual based on the concept of protecting themselves and the health of others, forming good hygiene habits and a civilized and healthy, green and environmentally friendly lifestyle to improve mental health Level and health literacy level.

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 nucleic acid test is positive, there is no need to panic. Actively cooperate with the medical and health institutions to do health monitoring and isolation medical observation. After fever, cough and other symptoms appear in time, report to the medical institution for standard diagnosis and treatment.

Source

Special Report: Fighting The New Coronavirus