Sanjin New Origin Market What has been found by the China CDC Virus Disease?

Medical Network June 19 - June 17 at 8 p.m., a bus in Beijing's Xicheng District, 100 Yingxin Street, the Southern District of the China Center for Disease Control and Prevention virus disease emergency startWu Guizhen, chief expert on biosecurity at the China Center for Disease Control and Prevention and secretary of the Party Committee of the Virus Disease Institute, led a team of people to the car in a hurry and rushed to the wholesale market of agricultural products in the new spot of the outbreakThis is the third time that viral diseases have entered new places to carry out virus tracing work.On June 11th Beijing re-emerged with out-of-date local cases after 57 consecutive days without new confirmed casesWhere the sudden new crown virus came from has attracted attentionThree into the new origin, China CDC virus disease found what? What are the latest developments in virus tracing? The website of the State Supervision Commission of the Central Commission for Discipline Inspection interviewed the relevant experts of the virus disease institute.On June 14 thand 15 and 17, experts from the Virus Disease Institute entered the new origin agricultural products wholesale market three timesdetected positive specimens of nucleic acid of the new crown virus in xinfa.It is understood that the first virus disease specialisttook a total of more than 200 samples, including a number of new coronavirus nucleic acid positive samples detectedThe second time, they touched melons and collected more than 200 samples in other areas, many of which were positiveFor the third time, scientific collection and testing of water systems such as water, fish farming and water conservation, canals and groundwater in the market were carried out, and air samples were also collected to determine the risk of aerosol propagation, which is currently being tested.Why can I take so many positive samples in a short period of time? What does that mean? " Many of us have participated in retrospective work in Wuhan before, but still have some experience Liu Jun, deputy director of the National Influenza Center, as head of the traceability group in Wuhan, explained: "How the virus came, there is some speculation that contaminated seafood or meat food through cold chain transport to the market caused by transmission, or infected people enter the market caused by transmission." For these two possible sources, we speculate on some environmental locations that the virus may contaminate, as well as items of food, and so on For example, we first of all fish and shrimp and other frozen products and may be a large number of exposure to these frozen plate, counter, case board testing, they are very likely to be contaminated by the virus In addition, we also think that the new crown virus infected people in the market after detoxification, may pollute where? For example, he sneezes will not hit the wall or the surface of the refrigerator, will not pollute the ground, will contaminate the surrounding fish tank and ditch, and so on, these are the key samples we have to focus on sampling "
" on the other hand, we have detected so many positive samples also show that the entire environment is still more serious According to Wu Guizhen researchers, the first time they entered the new site, they detected some positive samples at a seafood shop on the ground floor, including an entire salmon's oral swabs, as well as a nearby ditch; " In the work of virus traceability, sampling and detection of environmental samples is very important "Liu Jun's environment includes fish and shrimp shells, fish-fishing water, frozen products in the refrigerator, and so on." Different positive samples point to different conclusions: it may point to the environment and that the animal sonituated in it is the source of infection, or it may point to the source of infection in person infected with the new coronavirus For example, if we find a positive sample in an unopened frozen product, which further confirms the possibility that the virus could spread through cold chain transport to the market, and if the frozen product is unopened, it suggests that the frozen product may have been previously exposed, then the conclusion is not the same Liu Jun said .　　At present, the whole gene sequencing of dozens of positive specimens by viral diseases is still under way in a tense and orderly manner .　　The wet and cold closure of the seafood market easily leads to the rapid spread of the virus
since the outbreak of new clusters, the cumulative number of confirmed cases in Beijing has exceeded 100 cases, reaching 158 cases Why is the outbreak concentrated in the wholesale market and a large number of cases in a short period of time? .　　As the head of the trace group of the virus-traced work that went to Wuhan for viral disease, Liu Jun has entered the South China seafood market in Wuhan 20 times before, and this time three times into the wholesale market of agricultural products in Xindai " I've been in both markets because it's a seafood market and we can see that their environment is wet and cold And micro-organisms including viruses it is afraid of heat and cold, in such an environment can survive for a long time And here is not only wet and cold, they are also closed, poor ventilation, which will also contribute to the spread of the virus For example, a new crown virus infection person sneezes, it is difficult to spread out, droplets may sink to the ground, after the water sweeps to contaminate other places Liu Jun said " Therefore, a ventilated and dry environment is detrimental to the spread of the virus, while a wet and closed environment is relatively easy to lead to the rapid spread of the virus Liu Jun concluded .　　The wet-cold closure of the seafood market facilitates the survival and spread of the virus, which helps explain why there are so many cases here in a short period of time However, this does not mean that the seafood market itself is the source of the virus " Exactly where the virus originated and why the outbreak is concentrated in the seafood market are two different levels of question Can't because the virus is concentrated in the seafood market outbreak, it is concluded that the virus must have originated here Liu Jun said " We used to look for intermediate hosts when we were doing virus tracing, and now may be the time to take a fresh look at whether the virus is coming from wild animals Wu Guizhen said: "This outbreak rebounded in Beijing, but also in the wholesale market concentrated outbreak, but unlike Wuhan South China seafood market, Beijing's wildlife caused by the outbreak is very unlikely." This leaves us with an important reminder: It is possible that the source is an infected person or contaminated food, and the seafood market environment gives it the opportunity to spread quickly Wu Guizhen said .　　Liu Jun also believes that the new source of the virus, it is possible that contaminated seafood or meat food through the cold chain transport to the market caused by transmission, may also be infected into the market caused by transmission "There are different possibilities, but the likelihood of this outbreak coming from wildlife is very small." .　　The new coronavirus detected in the new place is older than the virus now prevalent in Europe
June 16, China's CDC director Gao Fu in a public statement speculated that: " (new crown virus) will be in some dark wet, more polluted, bad environment lurking, this is not thought of." After lurking down, in a certain period of time and then suddenly exposed to a number of people Beijing this time is probably not the beginning of June, the end of May only appeared in the patient, it is likely to be pushed a month in advance, which already has a lot of asymptomatic infection or light patients, so that the environment can have so many viruses "
" detected a large number of positive specimens in the environment of the wholesale market of new origin agricultural products, and did give us some hints: the virus has been in the country for some time If it's only a short time, it probably won't have such a large pollution range Of course, more data is needed to prove it Zhang Yong, assistant director of the Viral Disease Institute, said .　　Early and late in determining the timing of the virus epidemic, the main method of genomic epidemiology is now taken "First of all, the whole genome of the virus sequencing, sequencing using bioinformatics analysis methods, put different viruses together, see which virus mutation more, change more generally is the evolution of the updated virus, fewer mutations closer to the original virus, it is earlier, the age is older." Of course, these are popular sayings There are also specific algorithms that are calculated by mathematical models Liu Jun said " Preliminary results from genomic epidemiology suggest that the virus is from Europe, but it is different from the current epidemic in Europe, it is older than the current European epidemic virus "As for how on earth did the virus get in?" "There are several possibilities involved, " Zhang said For example, the virus lurks in imported frozen food, in the entire storage from outside to the territory of the transport period,
the virus because frozen did not occur evolution, so it will not change; "
although the path of transmission of the virus has yet to be confirmed or verified by more evidence, the initial genomic epidemiology of this speculation may provide a useful way to solve the mystery of the source of the virus in the new country," he said Streaming and big data can find a link between cases, but sometimes it's impossible to tell who's infected Through laboratory testing and gene sequence analysis, we can tell the path of transmission between them And when we speculate on possible transmission relationships between viruses, we can further look for evidence through flow and other methods With the support of major national science and technology projects, viral disease institutes are leading the national preparation of virus-wide genome-based virus network monitoring and tracing technology system, in order to deal with the virus traceability, a major issue related to national security virus disease prevention and control Zhang Yong said .　　How on earth did an old virus, which is prevalent in Europe, be brought to the wholesale market of agricultural products in Beijing's Xinfadi? Scientists are still exploring day and night .