Recently, many outbreaks are "material-to-human", and experts suggest that there are at least three conditions for clinical symptoms

On February 3, the press conference on the prevention and control of the new crown pneumonia epidemic in Hangzhou, Zhejiang Province, reported that the epidemic finally ushered in an inflection point, and the comprehensive analysis of the epidemic has been cleared by the community, and the next step is to shift from community clearance to isolation point clearance.

On January 28, Lou Xiaoming, deputy director of the Zhejiang Provincial Center for Disease Control and Prevention, introduced at the provincial epidemic press conference that from the current epidemiological investigation and analysis, the transmission chain of the epidemic is relatively clear. The preliminary judgment is transmitted from things to people, and then transmitted by people's specific activities. According to the press conference on the prevention and control of the new crown pneumonia epidemic in Zhejiang Province held on the afternoon of January 27, a number of positive copies of Omilon nucleic acid were detected in the imported materials that Huierte (China) Catering Equipment Co., Ltd. did not use.

In addition, the Health Times combed and found that many recent outbreaks have been "material-to-human".

Beijing: Exposure to international mail prior to illness

On January 17, 2022, Beijing reported the traceability of the local confirmed case in Beijing on January 15: the case had no history of travel in other provinces and cities in the 14 days before the onset of illness, and occasionally received and received international mail during the work.

The case is self-described, during which time it only touched the outer surface of the mail package and the front page of the document paper, and did not touch the inner surface of the package and other paper. At present, 22 specimens of the international mail environment have been collected, including 2 outer surfaces of the package, 2 inner surfaces and 8 paper specimens in the documents, all of which were positive for nucleic acid testing, and the specific mutation sites of the Omicron strain were detected.

Shenzhen, Guangdong: Overseas items are highly likely to be infected

On January 10, 2022, the press conference on the epidemic situation in Shenzhen, Guangdong Province, reported that the four cases infected with the virus were all Delta variants and were 100% homologous. The "case 1" in this epidemic is engaged in international goods supply chain work and has a recent history of contact with overseas goods. According to comprehensive analysis, the current epidemic is a local epidemic caused by overseas imports, and it is likely that the infection caused by exposure to new coronavirus pollutants outside the country is high.

On January 17, the Shenzhen Municipal Epidemic Prevention and Control Press Conference reported that case 17 was engaged in the collection and delivery of overseas frozen reagents, contacted and spun off couriers from North America on January 12, did not do personal protection, appeared sore throat symptoms on the 14th, and initially screened positive nucleic acid on the 15th, and did not rule out the possibility of infection caused by exposure to new coronavirus contaminants imported from abroad.

Ningbo, Zhejiang: The possibility of "material transmission to people" is not excluded

On January 3, 2022, ningbo city, Zhejiang Province, the press conference on the prevention and control of the new crown epidemic reported that the gene sequencing results of the first case specimen were the Delta variant of the new crown pneumonia virus (AY.57 evolutionary branch), which has high homology with the genome sequence of the main epidemic strain in Vietnam recently. The source of the virus is currently unknown. According to expert analysis and judgment, the possibility of "material transmission to people" is not excluded.

Manzhouli, Inner Mongolia: Preliminary analysis is overseas goods

On November 30, 2021, the press conference on the prevention and control of the new crown pneumonia epidemic in Manzhouli City was announced, and after a large number of visits, investigations, research and judgment, and comprehensive consideration of the national disease control virus detection and gene sequencing, the initial analysis of the epidemic in Manzhouli was that the virus carried by overseas imported goods, and the spread of the epidemic was caused by "human-to-human and material-to-human" methods.

Can the new coronavirus really be "passed from thing to person"? Does an item carrying a virus necessarily infect a person?

On January 19, 2022, Zhao Wei, a professor at the School of Public Health of Southern Medical University, said in an interview with CCTV's "News 1+1" that as early as October 17, 2020, during the outbreak of the new crown epidemic in Qingdao, the Chinese Center for Disease Control and Prevention clearly isolated and cultivated the new coronavirus from the cod outer packaging bag transported in the cold chain, and there was a relatively clear evidence of living new coronavirus infection. This is also the first time in the world that it has been confirmed that the items transported through the cold chain are "passed from thing to person", with clear evidence. This evidence was also published in the Journal of the Chinese Academy of Sciences and reviewed by scientists, so the evidence of "material transmission" in this case should be more accurate and sufficient.

Zhao Wei explained that the reports we have seen are that the article is positive for nucleic acid, and this "positive for nucleic acid" does not mean that there must be a live virus on the surface of the article. Because when the virus is present on the surface of the object, if it is stored for a period of time, it will lose its vitality. However, the nucleic acid of this virus still exists, so there is a positive nucleic acid test on the surface of the article. If the virus of the positive article is to be transmitted to people and cause people to have clinical symptoms, at least three conditions must be met:

There must be a source of infection, that is, the virus on the surface of the object must be a living virus, not a corpse of the virus.

There must be a suitable route of transmission. The virus should enter the human body through the correct transmission route, and for the new crown, it is through the respiratory tract.

3, there must be susceptible people, that is, people who contact must have no immunity

Therefore, only the simultaneous satisfaction of these three conditions will cause this exposure to lead to human infection. (Lu Yang)