Since the first case was discovered on July 22, the total number of confirmed cases in Dalian has reached 52 in one week. In addition, the Dalian epidemic has spread to 9 cities in 5 places, and the situation of epidemic prevention and control is still severe. In "News 1+1" tonight (29th), Wu Zunyou, chief epidemiologist of the China Centers for Disease Control and Prevention, interpreted the Dalian epidemic.

The scale of the Dalian epidemic has been basically locked and no more cases will appear

Q: According to the epidemic curve of the date of onset of the Dalian epidemic and the epidemic curve of the report date, it can be seen that the highest point occurred on the 24th. How to treat this phenomenon?

　　Wu Zunyou said that these two charts show that the outbreak of new coronary pneumonia in Dalian has been detected relatively early, and many cases have not had clinical symptoms when they are detected. This means that the scale of the epidemic in Dalian has basically been locked, and no more cases will appear.

The confirmed cases in Dalian are basically transformed from asymptomatic infections, and there is no more risk of transmission to society

Q: It can be seen from the situation in the past two days that the newly confirmed cases in Dalian are mainly asymptomatic infections transferred to the diagnosis. Can it be understood to some extent that the epidemic in Dalian has been basically controlled?

Wu Zunyou, Chief Expert of Epidemiology, Chinese Center for Disease Control and Prevention: It can be interpreted like this. Because Dalian first reported three confirmed cases and 12 asymptomatic infections on July 22. Asymptomatic infections accounted for such a large proportion, indicating that they caught the epidemic as soon as the epidemic occurred. Later, they carried out nucleic acid tests and found more asymptomatic infections. Afterwards, the confirmed cases were basically developed from asymptomatic infections. These were all within the control range of the local health system, which is a great impact on society. There is no more risk of transmission.

　　Wu Zunyou also said that Dalian's rapid response is very related to the response ability of the local health department and the timely treatment of occasional patients after symptoms appear. If the early case is not serious and cannot be treated in time, the health system will not be able to capture the case, which will cause delay in the detection of the epidemic. It is found that the consequences of delay are very serious, especially in cases with mild symptoms. If he does not see a doctor, it will continue to cause the spread of the epidemic.

Q: Why are there many young people, mild symptoms, and asymptomatic infections in the Dalian epidemic ?

Wu Zunyou, chief expert of epidemiology at the Chinese Center for Disease Control and Prevention: This can be seen from several aspects. First of all, the epidemic in Dalian mainly occurred in a workplace. In the workplace, it is mainly people who are under the age of 60. For example, if they are infected with new coronary pneumonia at this age, their epidemic situation is relatively mild. It will be too heavy. On the other hand, the outbreak in Dalian was discovered early and in a timely manner, so most of the patients were discovered before he had just been infected with clinical symptoms. Early detection is of great help in preventing the severity of the case from developing. Helping. So these two factors explain why the Dalian case had mild symptoms and there were more asymptomatic infections.

Places where seafood is sold and processed should pay special attention to preventing the new coronavirus

Q: This round of Dalian epidemic is mainly from a seafood company in Dalian. More than a month ago, the Beijing epidemic was also related to frozen fresh food. Are there any connections between them?

Wu Zunyou, chief expert of epidemiology at the Chinese Center for Disease Control and Prevention: The Dalian epidemic and the Beijing epidemic have a great similarity, that is, both are related to seafood processing or sales. In fact, when the new outbreak occurred in Beijing, we thought that the South China Seafood Market in Wuhan was also related to the seafood sales area. This series all reminded that these places have a common environment, that is, humid, relatively low temperature, suitable for The virus survives. As long as there is pollution, the virus in local areas may accumulate more and more, and it is not easy to inactivate, making these places a risk of transmission. We have also done some investigations in Beijing, especially in Xinfadi. Will environmental pollution cause human infections in the future? We use fluorescent powder fake virus as a simulation experiment, suggesting that in such an environment, the aerosol produced by some operations can infect practitioners; after the practitioner is infected, a mixed transmission mode is formed in the polluted environment . Therefore, special attention should be paid to preventing new coronary pneumonia in places where these seafood are sold and processed.