Salmon is not infected with the virus, but low temperature environment seiscant the virus to survive.

On June 12, between 16:00 and 2400 hours, 4 new confirmed cases of new coronary pneumonia were reported in Beijing, and 46 asymptomatic infections were screened.
, deputy director of the Beijing Center for Disease Control and Prevention Pang Xingxing june 13, the epidemiological investigation shows that these cases have a new history of agricultural products wholesale market activities, through the collection of confirmed cases related to the external environment specimens, nucleic acid test positive report.
preliminary judgment, these cases may have been infected by exposure to contaminated environments in the market or in contact with infected persons.
according to Beijing in the wholesale market of farmers, large supermarkets and other places of inspection, a total of 5424 samples of seafood, meat and other food and external environment smeared samples, completed the new crown virus nucleic acid test, of which 40 from the new origin market environmental samples positive, the rest of the samples are negative.
At the beginning of the outbreak of Wuhan Xinguan, the CDC virus had detected 33 samples containing neo-coronavirus nucleic acid from 585 environmental samples from the South China seafood market and isolated the virus from positive environmental samples.
Now, Beijing's new case of new crown pneumonia is once again focusing on the seafood market.
salmon is not infected with the virus, but the low temperature environment is conducive to virus survival for the new market found 40 environmental lying positive sample sourcing source, Beijing Municipal Health and Health Commission spokesman Gao Xiaojun responded to China Newsweek: "Some from the salmon case board, some are not."
" in the early hours of June 13, Beijing Xinfadi wholesale market chairman Zhang Yuxuan in an interview with the media, said: "The relevant departments during the sampling from the cutting of imported salmon in the case board detected the new crown virus, and the source of the product from the Beijing-Shenzhen seafood market."
" reported that, affected by the news, Beijing's main business super-enterprise supermarket hair, the United States, Carrefour yesterday has been overnight all the salmon. Cheng Gong, a professor in the Department of Basic Medicine at Tsinghua University Medical School in
and an expert in virology, told China Newsweek that "detected viruses" have two concepts, one is nucleic acid testing, that is, the virus's DNA or RNA, which can only indicate that the virus has existed in the object or its surface, such as sneezing or other infectious substances contaminated salmon and case board, leaving the virus "trace", but can not determine the virus activity;
Cheng Gong further explained that the virus to infect must have a corresponding host, such as dengue virus infection people or some primates, and some viruses can infect fish, insects or horses and other animals, this specificity is because, in different animals, the virus needs a different host receptor, so only the receptors of specific animals can make the virus infected cells.
, for example, HIV-infected people need only the receptors on the human cell, and mosquitoes although sucking human blood but not from human infection with HIV.
the new coronavirus belongs to the genus beta-coronavirus, and so far, known scientific evidence suggests that its host-infected receptors are present in mammals and do not exist in fish.
the new coronavirus invades the host, mainly through its own S protein and binding to the ACE2 receptor on the host cell.
On May 1 this year, the team at University College London published an article on the preprinted platform bioRxiv, predicting that the SARS-CoV-2 virus can form a stable complex with the receptor protein of mammalian host, but not with fish, birds or reptiles.
April, a paper co-authored by experts from the United Nations Food and Agriculture Organization, the Chinese Academy of Aquatic Sciences, the Yellow Sea Fisheries Research Institute of the Chinese Academy of Aquatic Sciences and other institutions also pointed out that the new coronavirus belongs to the coronavirus family, which only infects mammals.
, then, is it possible that salmon is only a attached vector or medium, the virus in the processing, transport chain and lead to transmission? Cheng Said it was possible.
generally speaking, if the virus is more resistant to the outside world, it will survive for a long time at low temperatures or in cold conditions.
"We usually keep virus samples, but also in ultra-low temperature refrigerators, or -20 to 80 degrees, can be stored for half a year or even years." "So if fish are contaminated with the virus abroad and then enter the country in cold chains, it's possible,"
. On the evening of June 12,
, the Beijing Municipal Market Supervision Bureau issued a notice, Beijing launched a food safety inspection, a comprehensive inspection of food safety risks.
however, several virologists explain that the likelihood of contracting the virus by eating is lower.
, University of Hong Kong virology experts, medical professor Jin Dongxuan told China Newsweek, because the new coronavirus is a respiratory-transmitted disease, it is mainly by the nose after breathing from the mucous membranes of the nose wing into the human body, and eating is through the digestive tract, such as hepatitis A infectious diseases are infected through the digestive tract, but the new crown is not.
Cheng Gong further explained that the possible transmission chain is, in the process of processing ingredients, such as opening packaging, hand-operated ingredients, contaminated ingredients in the operation of the formation of aerosols, that is, some of the air suspension, the formation of virusspread and from the respiratory tract, eye mucous membrane into the human body.
the opportunity to find a middle host and the seafood market-related outbreak of new crown pneumonia has also been reported abroad.
According to Yonhap reported on March 12, located in Sejong City, South Korea's Ministry of Marine Fisheries 10, the first confirmed case, as of the 16th, 27 workers have been confirmed infected with xinguan pneumonia, the path of infection is not clear.
French doctor Yves Cohen told the media on May 3, after retesting samples of nucleic acid tests for patients with viral pneumonia between December and January last year, they found that a patient sample had tested positive for a new crown, and Cohen conducted further investigations and found that the patient had no travel history in China and had not been exposed to any suspected cases other than his wife.
notable, the patient was a fishmonger and his wife worked at the seafood counter.
the discovery, published in the International Journal of Microbiology, is thought to be a "patient number zero" in France.
American Seafoods, North America's largest seafood fishing company, said on June 1that 86 crew members of its fishing processing vessel, the Us Dynasty, had been confirmed to be infected with the virus, and that nine were still awaiting test results.
Seattle-based American Seafood Company, is one of the world's largest marine traders in the Wild Pacific without cod and wild Alaskan cod, with six fishing vessels operating in the Bering Strait and the North Pacific.
Chenggong pointed out that China's seafood market is a more complex environment, because the market often also sells chicken, duck, sheep and other meat food, so whether it is because of aquatic products or other factors in the environment led to the infection of the new coronavirus is difficult to say.
Jin Dongxuan also said that now occurred in Beijing's new origin market infection, is likely to be human-to-human, but has not yet found that source, which is common around the world.
But if there is really an animal-to-human transmission, it is very dangerous, should be highly vigilant, because China is so large, so many places, do not know what conditions it will also occur animal-to-human transmission.
" in fact, when SARS was able to control so quickly, is because at that time the fruit beaver this source of infection to find the right, the elimination of the fruit beaver on the intermediate transmission of the way to cut off.
" Cheng Gong said, but now the biggest problem of the new crown outbreak is that we did not find this intermediate host, a guess is pangolins, but pangolins in China has been functionally extinct (one or a certain species of organisms in natural conditions, the population population reduced to a state of inability to maintain reproduction), a guess is that bats, but when the outbreak in Wuhan, the bat is actually hibernating.
"To learn more, you need animal samples from the market, but if everything is disposed of and disinfected, there is no opportunity for further research." Peter Bogner, chairman of GISAID, a global bird-sharing data initiative
, told China Newsweek earlier.
for the current test results of the new origin market, Jin Dongxuan said, "all found on the case board virus, and with the outbreak so close, this should be very well-equipped to make this thing clear."
"what the real intermediate host is, this is the biggest problem, if the intermediate host can not be found, there will be a steady stream of new coronaviruses to human input."
Beijing this time in the new site of the outbreak is a very good scene, what exactly animals carry and spread the virus, a good study, perhaps can seize some clues, the real intermediate host to find out.
," Cheng said.
13 reported that Beijing issued a case of asymptomatic infected people from the "Haidian District of a farmers market."
at 5 p.m. on the same day, "China Newsweek" reporter came to the rumored incident in Beijing Haidian District Yuquan Dong commodity trading market, found that the market South Gate has pulled up the blockade line.
staff wearing Haidian District CDC uniforms told reporters that the market has been blocked, has been taken environmental samples for inspection.
the scene of Haidian District industry and commerce, disease control, public security and the street staff in the market staff and vendors in the transfer work, at least three buses mobilized to participate in this operation.
reporters from a field staff learned that at least 240 market staff and vendors will be tested for nucleic acid.
the afternoon of the 12th, they have carried out fish and shrimp and other seafood and meat sampling, the current market all goods in place sealed, has not yet carried out culling treatment.
" From an epidemiological point of view, in the short term, there are more cases in a certain area, which can be said to be an outbreak of infectious diseases. "However, the scale of the outbreak in Beijing is difficult to tell, and the next steps will be to be given," Jiang Qingwu, a former dean of the School of Public Health at Fudan University, told China Newsweek.

" Jiang Qing five analysis, the current 517 samples collected from the new origin, 45 people were positive for pharynx swabs, close contacts detected a positive proportion of less than 9%.
the scope of screening, the proportion of positive tests must be less than 9%.
it's too early to say how large the outbreak will be, and experts involved in the survey need to publish more results and explain them.
Source: China Newsweek.