At present, the spread of the local epidemic in China has been basically blocked. With the “unblocking” of Wuhan, the emergence of asymptomatic new coronavirus infections has attracted much attention. What are asymptomatic people and how contagious are they? How to deal with the risk of transmission of asymptomatic infections after resuming labor and resuming labor? How do relevant departments and local governments manage and control, and how to check? How should the public protect themselves? For these focus issues that are generally concerned by society, Xinhua News Agency interviewed relevant experts to find out.


Focus One: How infectious are asymptomatic people?

Statistics show that 31 provinces (autonomous regions and municipalities) and Xinjiang Production and Construction Corps reported 63 new cases of asymptomatic infections on April 11, Among them, 12 cases were imported with asymptomatic infections; 14 cases were converted to confirmed cases on the same day (14 cases imported overseas); 55 cases were released from medical observation on the same day (4 cases imported overseas). 1086 cases of asymptomatic infection are still under medical observation (332 cases imported from abroad).

Wei Sheng, a professor at the School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, said: “The infectiousness of asymptomatic patients depends on different situations, if it is isolated in Wuhan The asymptomatic infections found only after so many days are very infectious. If they are found in people who are returning from areas that are endemic in foreign countries, the infectivity is very high. It is necessary to judge each case separately. ”

According to Tong Zhaohui, a member of the expert group of the Central Steering Group and the deputy director of Beijing Chaoyang Hospital, there are two types of asymptomatic infections: one is a patient diagnosed with new coronary pneumonia, but only In the incubation period, there are no symptoms, and they need to be screened out and included in the diagnosis case management; the other type has no symptoms and no image changes. They are truly asymptomatic infected people. They are not patients, but only have positive nucleic acid tests.

The National Health Commission organized experts to analyze the asymptomatic infections reported from January 29 to April 8 and turned into confirmed cases, and found asymptomatic infections in China The proportion of people who turned into confirmed cases showed a gradual downward trend. After March 10, the proportion of confirmed cases remained below 11.2%, and in some provinces the proportion was relatively low, below 6%.

Tong Zhaohui said that from the medical judgment, asymptomatic infections have a certain degree of infectivity, but the infectivity is generally weak, and the infectivity is much lower than that of symptomatic. “Without sneezing, coughing and other symptoms, the virus-containing droplets cannot be discharged in the respiratory tract, and the chance of transmission is relatively less.”

Natural magazine recently published a paper entitled” Virology Evaluation of New Coronavirus Pneumonia Inpatients “, a study by the team of German scientist Christian Traussen showed that the symptoms of the new coronary pneumonia After 8 days, live virus will not be isolated, indicating that the patient has not been living with the virus for a long time.

Wei Sheng said that most residents in Wuhan have been isolated at home for more than 70 days, but no Symptoms, people with a “green code” are less contagious. “Wuhan has gone out a lot of people recently, and very few people have asymptomatic infections. ”


Focus 2: Will the asymptomatic infection cause a rebound of the epidemic? ?

On April 8th, the 76-day Lihan Channel was closed and reopened. After the Wuhan “unblocked” and resumed work, asymptomatic infection spread Risk is a concern.

Li Qun, director of the Center for Health Emergency Response of the Chinese Center for Disease Control and Prevention, said that preparations for resuming work and resuming production have been done, in order to cope with the increased mobility of personnel, which may bring Risk of transmission. Once an asymptomatic infected person is found, carry out quarantine observation and detailed epidemiological investigation in a timely manner, and at the same time, strengthen targeted control and monitoring of some key places, key populations, and key areas. “Through these efforts, we hope to find more asymptomatic infected people and reduce the chance of transmission.”

“The existence of asymptomatic infected people is the rule of infectious diseases, measles , Flu, SARS, etc. have a certain proportion of asymptomatic infections, they have not caused a large spread in society. “Tong Zhaohui said, 2003 SARS and the early epidemiological investigation of new coronary pneumonia evidence, all proved asymptomatic infection There is a certain degree of infectivity, but the infectivity and spread are limited and will not cause large-scale spread of the population. As long as hospitals and disease control agencies fully implement the “four early” requirements for the prevention and treatment of infectious diseases, they can well control the transmission risk of asymptomatic patients.

“Whether an asymptomatic infected person will cause the epidemic to rebound, more importantly depends on the attitude and ability of prevention and control work. If you do not pay attention, even if only a small number of Symptom-infected people may also cause disease transmission; if we pay attention, even if there are asymptomatic infected people, as long as the prevention and control measures are effectively implemented, one is found, one is controlled, and the work of discovery, control and control is solid There is a problem. “Li Qun believes that at present all aspects have attached great importance to the prevention and control of asymptomatic infected persons, the monitoring work of professional departments has been continuously strengthened, the prevention and control measures and processes have been continuously optimized, and screening of key populationIt is also continuing, and there is no need to worry too much about asymptomatic infections will cause outbreaks.


Focus 3: How to troubleshoot and control people with asymptomatic infection?

According to experts, there are mainly several sources of asymptomatic infections detected in Wuhan, Hubei: First, they are isolated from close contacts of confirmed patients; The second is to screen out the ordinary patients who came to the hospital for treatment; the third is to screen out the organization of some enterprises before resuming production; the fourth is to screen out the separated Chinese personnel.

Once an asymptomatic person is identified, what measures will be taken to respond?

Li Qun said that if any asymptomatic infected person is found in various types of medical and health institutions, they should report directly to the Internet within two hours. After receiving reports of asymptomatic infections, the CDC at the county / district level must complete the case investigation of asymptomatic infections within 24 hours.

“For asymptomatic infected persons, the same strict measures as the diagnosed cases are adopted. Asymptomatic infected persons are found to be very management, isolation, and medical observations. Strict. “Li Qun said,” People with asymptomatic infections must be focused on medical observation for 14 days. Once symptoms appear, they will be transferred to a designated hospital for treatment. If the diagnosis can be confirmed, they must be corrected as confirmed cases. After that, two weeks of health follow-up will be conducted, and at the same time in the second and fourth weeks, they will go to the designated hospital for re-examination. Close contacts of asymptomatic patients will also be subject to medical observation for 14 days. “


Focus 4: How should the public view and protect?

In response to some of the panic emotions of asymptomatic infected persons, Tong Zhaohui said that close contacts of confirmed cases are the main source of asymptomatic infected persons, People who have not been exposed to patients with new coronary pneumonia are generally not infected and there is no need to panic.

Li Qun said: “The public should be aware of the risk of infection without excessive worry, even when it is impossible to distinguish whether there are asymptomatic infected people around, The important thing is to do personal protection. “

Experts generally believe that ordinary people without symptoms and suspicious contact history do not need to do nucleic acid screening. Large-scale screening of the general population is neither feasible nor necessary. All the public has to do is to protect and protectBecome a good hygiene habit, increase nutrition, rest well, and improve your own immunity.

Normative protection is also very important, “We may also have some subconscious movements, some bad habits are not noticed, such as touching the surface of the mask with your hand Let’s rub our eyes again. “Li Qun said that on the one hand, the public must be conscious of personal protection, on the one hand, they must know how to regulate protection.

“I hope that after the epidemic, everyone can develop some good hygiene habits, which is not only beneficial to prevent the new coronary pneumonia epidemic, but also to prevent and control other infectious diseases.” An expert said that good hygiene habits such as face mask hygiene, hand washing hygiene, and maintaining social distance should be maintained.

(Originally titled “Focus Issues on Asymptomatic Patients with New Coronavirus”)