Source of seafood market


The origin of NCV has always been concerned by the domestic surgical community. Some studies suggest that Wuhan south China seafood market is not the origin of the virus. Recently, with the isolation of live neocoronavirus from the outer packaging of cold chain food in Qingdao for the first time, and a paper that the new outbreak in Beijing may be caused by cold chain food contamination, it seems to propose another possibility for virus traceability. Wu Zunyou, chief epidemiologist of the Chinese Center for Disease Control and prevention, said in a recent media interview, “since the outbreaks in Xinfadi, Dalian and Qingdao are all caused by seafood, we think that the earliest outbreaks in Wuhan were also in the seafood market in South China, and whether they were caused by imported seafood. This also gives us a hint So that we have a new idea and a new technical direction. “
According to the information released by the China Center for Disease Control and prevention on the 17th, during the investigation on the source of the epidemic situation in Qingdao, the Chinese Center for Disease Control and prevention detected and isolated the new coronavirus from the outer package of imported frozen cod carried by workers. This is the first time in the world that the new coronavirus has been isolated from the outer package of cold chain food and confirmed for the first time that the new coronavirus can be found on the outer packaging of articles under special conditions of cold chain transportation The survival time of the new coronavirus is longer, which indicates that the new coronavirus can be imported into the cold chain goods for a long distance. Moreover, under certain environmental conditions, the virus on the surface of the article may lead to infection of susceptible contacts without effective protection. At a press conference held by the Qingdao municipal government on the morning of 20, Luan Xin, vice mayor of Qingdao, said that a complete chain of evidence has been found in the prevention and control of the epidemic in Qingdao, indicating that the new coronavirus can be transmitted from human to human and can survive for a long time under frozen conditions.
Gao Fu, director of the Chinese Center for Disease Control and prevention, said, “in the past, the nucleic acid positive of coronavirus was not necessarily a live virus. This” isolation “of the live virus means that there must be a live virus, which can cause transmission or infection It is worth mentioning that as the “zero patient” of the epidemic in Qingdao, Dong and Chen were stevedores in Dagang, Qingdao, who loaded and unloaded frozen seafood imported from abroad on the night shift on September 19.
Novel coronavirus pneumonia, China’s Academy of Sciences, China, Beijing, Tsinghua University, the center for Disease Control and prevention, the Institute of pathogen biology, Chinese Academy of Medical Sciences, Peking University and the Beijing Institute of genome research, Chinese Academy of Sciences, published a research paper entitled “the emergence of new crown pneumonia in Beijing, possibly from cold chain food contamination”, published on the 23 National Journal of science and technology. Based on the nucleic acid sequencing and virus genome sequence analysis of the epidemic related cases, environment and food samples in Beijing in June 2020, combined with the comprehensive epidemiological survey and big data analysis, this paper reveals that the epidemic may be caused by cold chain food pollution, and proposes that cold chain transportation may be a new way to spread the new coronavirus.
Not only in Qingdao and Beijing, but also in Dalian in July, most of the confirmed cases in the past few days were employees and family members of Kaiyang seafood company. Although there was no live virus isolated from the cold chain aquatic products and a complete infection chain could not be formed, the possibility of virus transmission through cold chain transportation still exists.
Some experts in related fields have noticed that articles transported by cold chain, especially imported seafood, can transmit new coronavirus, which may provide a new research direction for virus traceability in Wuhan south China seafood market. As the largest aquatic product wholesale market in Central China, South China seafood market has a large number of imported products transported by cold chain. Yang zhanqiu, a professor at the Institute of Virology, School of basic medicine, Wuhan University, told the global times on the 28th that it is possible for the new coronavirus to be introduced into the seafood market of South China through cold chain transportation if there was any import seafood trade.
The Global Times reporter found that there were many shops selling imported fresh seafood in South China seafood market, including king crab, Arctic shell and other seafood, as well as meat products from Brazil and Germany requiring cold chain transportation.
Wu Guizhen, chief biosafety expert of China CDC, also mentioned in a recent media interview that “in the past, we have been looking for intermediate hosts when we were doing virus tracing. Now maybe it is time to reexamine whether the virus comes from wild animals or not.” Wu Guizhen said, “the epidemic situation rebounded in Beijing and also concentrated in the wholesale market. However, unlike Wuhan south China seafood market, the possibility of wild animals causing the epidemic in Beijing is very small. This leaves us with a very important hint: is it possible that the source is an infected person or contaminated food, and the environment of the seafood market creates opportunities for rapid transmission. “
But at present, there is still lack of sufficient evidence to support the formation of a clear chain of infection. Yang zhanqiu mentioned that if the source is locked in the imported products of cold chain transportation, it is necessary to answer the core questions of how the products are contaminated by the virus and where the source is. One possibility is that foreign personnel involved in cold chain transportation have been infected with the new coronavirus and spread the virus to seafood and other products at work. Another possibility is that imported animal products themselves are infected with the new coronavirus. “Previously, the focus of virus tracing was on wild animals, such as bats, but it did not focus on the possibility of transmitting new coronavirus in fish, pigs, cattle, sheep, etc.,” Yang zhanqiu said. According to the past understanding of coronavirus, the virus infected by these animals would not infect human beings, but the new coronavirus might be overturned