On January 13, 2021, the Jilin Provincial Health Commission notified 1 case of asymptomatic infection. No one had expected that the asymptomatic infection imported from Heilongjiang Province would become the 102 asymptomatic cases in the next 4 days of epidemic notification. The source of infection in the infected and confirmed patients.

  On the afternoon of January 17, the Jilin Province epidemic prevention and control press conference announced that 102 cases of infection were transmitted by the same imported case Lin.

Mr. Lin is engaged in individual marketing and he is from Heilongjiang.

  A chain of transmission caused by asymptomatic infections

  On January 5, a 45-year-old Heilongjiang individual salesperson Lin Mou took train K350 (11 train No. 13) from Heilongjiang Nancha to Harbin West Railway Station.

Seats 27 and 28 of Car 11, not far from his seat, are a middle-aged couple who returned to Changchun from Wangkui County, Suihua City.

  On January 11, middle-aged couples were identified as asymptomatic infected persons.

On January 12, in response to the information pushed by Heilongjiang Province, Tonghua City immediately traced the individual marketing staff and performed a nucleic acid test on him. The test result was positive. After consultation with the clinical expert group, he was diagnosed as an asymptomatic infection.

This "individual marketer" is the "asymptomatic infected person notified on January 13th 3" that Jilin Province will repeatedly mention in the epidemic notification in the future.

  After the man's nucleic acid test was positive, Tonghua City carried out a follow-up investigation of his close contacts. Among the employees of the Yuansheng Quality Life Workshop he taught, 4 cases of asymptomatic infections were found associated with him.

  After that, within 4 days, 4 cases, 2 cases, 13 cases, 13 cases, 66 cases...

.There are more and more cases associated with it.

  On January 13th, 4 new cases were added: After the asymptomatic infection 3 nucleic acid test was positive, Tonghua City carried out follow-up investigations of their close contacts. Among the employees of the Yuansheng Quality Life Workshop, 4 cases were found related to them. Asymptomatic infection.

  2 new cases were added on January 14 Related: The Jilin Provincial Health Commission officially notified that at 0-24 o'clock on January 13th, 2 new cases of asymptomatic infections were reported in Heilongjiang Province on January 13th. Close contacts of symptomatic infected person 3.

  13 new cases related to January 15th: According to the report, 14 new cases of asymptomatic infection were reported in the province from 0-24 o'clock on January 14, 13 of which were the same as imported asymptomatic infections in Heilongjiang Province notified on January 13 3 is related.

  13 new cases related to January 16th: According to the report, 13 new cases of asymptomatic infections were reported in the province from 0-24 o'clock on January 15th, all of which were related to the imported asymptomatic infections 3 in Heilongjiang Province notified on January 13 .

A reporter from the Health Times noted that these asymptomatic infections participated in the training of the man at the Aishan Hanbang Health Club in Fanjiatun Town, Gongzhuling City on January 8.

  66 new cases were added on January 17 Related: According to the report, 63 cases of asymptomatic infections were reported in the province from 0-24 o'clock on January 16, 62 of which were the same as those imported from Heilongjiang Province reported on January 13 It is related. In addition to the 4 confirmed cases, all of them participated in the training course of asymptomatic infection 3 notified on January 13 at Yuansheng Quality Life Square in Tonghua City.

  On January 17, the Jilin Province epidemic prevention and control press conference again announced that as of 14:00 on January 17, Jilin Province had reported a total of 34 confirmed cases and 80 asymptomatic infections.

This epidemic in Jilin Province was imported by asymptomatic infected persons in Wangkui County, Heilongjiang Province, which caused local transmission.

Of the 114 cases of infection reported so far, 9 cases were imported from Heilongjiang Province and 105 cases were local recurring infections.

Among the recurring infections, 3 were family members of the imported infected person from outside the province, and the other 102 infected were spread by the same imported case Lin.

Mr. Lin is engaged in individual marketing and he is from Heilongjiang.

The initial asymptomatic infection has been diagnosed

  On January 13, according to the Jilin Provincial Health Commission:

  Asymptomatic infection 3: Male, born in 1976, from Hulan District, Harbin City, Heilongjiang Province, individual marketing staff.

  On January 5th, take the K350 train (11 train No. 13) from Nancha, Heilongjiang to Harbin West Station, in the same compartment as the asymptomatic infected persons 1 and 2 notified at 0-8 on January 11.

  On January 7th, take the Z174 train (2 train No. 6) from Heilongjiang Shuangcheng District to Changchun Station, and at about 15:00 from the passenger car of Huanghe Road Passenger Station to Fanjiatun Town, Gongzhuling City.

  At about 11 o'clock on January 8, the passenger car from Fanjiatun Town, Gongzhuling City returned to Changchun Station, and took the K1383 train (2 car No. 070) back to Heilongjiang Shuangcheng Castle.

  On January 9th, take the D124 train (5 trains No. 5A) from Harbin West Railway Station to Changchun Station, and then take Metro Line 1 to Changchun High-speed Passenger Transport Station, and the passenger train from Changchun to Tonghua at 12:35.

  From January 10th to 11th, the training will be conducted at Yuansheng Quality Life Workshop.

  On January 12, in response to the information that the person was a close contact pushed by Heilongjiang Province, Tonghua City immediately traced the person and performed a nucleic acid test on him. The test result was positive. After consultation with the clinical expert group, he was diagnosed as an asymptomatic infection.

  On January 16, the asymptomatic infection was converted to a confirmed case.

Asymptomatic infections may not have fewer respiratory viruses than those with symptoms

  "The respiratory virus of asymptomatic infections is not necessarily less than that of symptomatic patients." In this regard, Li Tong, deputy chief physician of the Department of Infectious Diseases of Beijing You'an Hospital, once said that the ability of people infected with the new coronavirus to spread depends on the amount of their own virus. , And the ability to spread infectious droplets.

The reason why asymptomatic infected persons are weakly contagious is that they do not have some symptoms such as coughing and sputum, and fewer viruses are excreted from the respiratory tract.

  "On the whole, in addition to the spread of droplets, it also depends on the space environment when contacting people. Temperature and humidity also have an impact on infection." Director Li Dong Zeng pointed out that if it is in a relatively confined space, such as elevators and cars , In the room, when people gather, it is possible to infect multiple people.

Since the super spreader of the Jilin epidemic is a training lecturer, asymptomatic infected people do not cough, but they also excrete the virus when they speak.

  "The boundary between asymptomatic infection and mild infection is actually easy to break. Some people think that if you have an itchy throat and a mild cough, you will have no symptoms. It may be like this. If you ask about it, you will say that there are no symptoms. If you find that the nucleic acid is positive, you may ask again. A mild cough with itchy pharynx can be used to diagnose mild infections. This is actually very common." Director Li Tong Zeng said.

  According to a report from the US Centers for Disease Control and Prevention, as of now, more than half of the new coronavirus infections in the United States have been transmitted through asymptomatic infections. It can be seen that the transmission power of asymptomatic infections is also changing.

  "The previous virus may be different from the current virus. Viral mutations may increase the transmission rate." Zhang Hongtao, research associate professor in the Department of Pathology and Experimental Medicine at the University of Pennsylvania School of Medicine, said that once the virus infects the human body, everyone’s symptoms are also different. Different, the amount of virus released varies, which depends on the individual's immunity.

He emphasized that the new crown vaccine is currently the most effective method.

Occupations with a large number of people should give priority to vaccination. The possibility of vaccinated infection is reduced, and the possibility of transmission will be reduced.

  Previously, Feng Zijian, deputy director of the China Centers for Disease Control and Prevention, said that a very high proportion of people infected with new coronary pneumonia do not spread and will not cause second-generation cases; but a small number of infected people or patients will spread more than the basic number— -3 or more, will spread more than 3 second-generation cases, which constitutes a super-spread phenomenon, which is a very important feature of the new crown.

He said that the new coronary pneumonia is a very prominent disease of super transmission, and reducing gathering activities is an important measure to eliminate super transmission.