What was discovered by the CDC virus disease in Sanjin New Place

8 p.m. on June 17, a mini-bus was bused in the southern district of the CDC's viral disease center at 100 Yingxin Street in Xicheng District, Beijing. Wu Guizhen, chief expert in biosecurity at the CDC and director of the Viral Disease Institute
led a team of people rushed to the car and rushed to the wholesale market of agricultural products in the new outbreak area where the outbreak began. This is the third time that a viral disease has entered a new place to carry out virus tracing.
June 11, Beijing re-emerged after 57 consecutive days of no new locally confirmed cases. Where exactly the sudden new coronavirus comes from has received much attention from all sides. Sanjin new place, China CDC virus disease found what? What are the latest developments in virus tracing? Reporters from the website of the State Supervision Commission of the Central Commission for Discipline Inspection interviewed experts related to viral diseases.June 14 and 15 and 17, experts from the Viral Disease Institute entered the wholesale market of agricultural products in Xinfa.
, it is understood that the first viral disease experts took a total of more than 200 samples, of which a number of positive samples of neo-coronavirus nucleic acids were detected. The second time, they groped melons and collected more than 200 samples in other areas, many of which were positive. Third, the market for water, fish culture and preservation of water, canals, groundwater and other water systems for scientific collection and testing, but also collected air samples to determine the risk of aerosol transmission, samples are currently being tested.
so many positive samples be collected in a short period of time? What does that mean?
many of us have participated in traceability work in Wuhan before, or have some experience. Liu Jun, assistant director of the Viral Disease Institute and deputy director of the National Influenza Center, explained: "How the virus came about, there is some speculation that contaminated marine products or meat food is transported to the market through cold chains to cause transmission, or that infected people enter the market caused the spread." For these two possible sources, we have speculated about some of the environmental locations that the virus may contaminate, as well as items of food, and so on. For example, we first of all on the fish and shrimp and other frozen goods and may be a large number of exposure to these frozen products of the plate, counter, case board tested, they are very high probability of virus contamination. In addition, we also think, the new coronavirus infected people in the market after detox, may pollute what places? For example, he sneezes will not hit the wall or refrigerator surface, will not pollute the ground, will pollute the surrounding fish tank and ditch and so on, these are our focus sampling. "
" on the other hand, we have detected so many positive samples also indicate that the whole environment is still more serious virus contamination. According to Wu Guizhen researchers, the first time they entered the new site, they found some positive samples at a seafood restaurant on the ground floor, including an entire salmon mouth swab, as well as a nearby ditch;
" in the virus tracing work, the sampling and detection of environmental samples is very critical. "The environment that Liu Jun is talking about includes fish and shrimp shells, fish-breeding water, frozen goods in the fridge, and so on." Different positive samples point to different conclusions: it may point to the environment and the animals or objects inside it are the source of the infection itself, or it may point to the person infected with the new coronavirus as the source of the infection. For example, if we find positive samples in unosted frozen products, this further confirms the possibility that the virus can spread to the market through cold chain transportation, and if the frozen products are unopturised, this suggests that the frozen products may have been previously exposed to people, then the conclusion is not the same. Liu Jun said.
, the whole genetic sequencing of dozens of positive specimens by viral diseases is still under way in a tense and orderly manner.the outbreak of new aggregation in Beijing, the cumulative number of confirmed cases in Beijing has exceeded 100, reaching 158. Why do outbreaks occur centrally in wholesale markets and in large numbers of cases in a short period of time?
as the virus disease to Wuhan to carry out virus traceability work traceability group leader, Liu Jun has previously entered the Wuhan South China seafood market 20 times, this time three times into the new origin of agricultural products wholesale market.
"I've been in both markets, because it's the seafood market, and we can see that they're wet and cold. And microorganisms, including viruses, are afraid of heat and cold, and can survive for a long time in such an environment. 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 coronavirus infection sneezes, it is difficult to spread out, droplets may sink to the ground, after washing the ground to pollute other places. Liu Jun said.
" so a ventilated and dry environment is detrimental to the spread of the virus, while a wet, cold and closed environment is relatively easy to cause the rapid spread of the virus. Liu Jun concluded.
closure of the seafood market is conducive to the survival and spread of the virus, which helps explain why a large number of cases occur here in a short period of time. However, this does not mean that the seafood market itself is the source of the virus.
two different levels of the problem is where the virus is at its source and why the outbreak is concentrated in the seafood market. You can't conclude that the virus must have originated here because it's concentrated in the seafood market. Liu Jun said.
we used to be looking for an intermediate host when we traced the virus, and now may be the time to re-examine whether the virus is from wild animals, " he said. Wu Guizhen said: "This outbreak rebounded in Beijing, but also concentrated in the wholesale market outbreak, but unlike wuhan South China seafood market, Beijing wildlife caused by the outbreak is very unlikely." This leaves us with an important hint: is it possible that the source is an infected person or contaminated food, and the environment of the seafood market gives it a chance to spread quickly. Wu Guizhen said.
Liu Jun also believes that the new outbreak of the virus, it is possible that contaminated sea products or meat food through cold chain transport to the market caused by the spread, it is also possible that the market infected people caused the spread. "There are different possibilities, but there is little chance that this outbreak will come from wild animals."on June 16th Gao Fu, director of the China Center for Disease Control and Prevention, speculated in a public statement: " (The new coronavirus) will lurk in some dark, humid, more polluted, bad environment, which is not expected." After lurking down, in a certain period of time and then suddenly exposed to a lot of people. Beijing this time is likely not the beginning of June, the end of May only appear patients, it is likely to be pushed forward a month, there are already a lot of asymptomatic infection or light patients, so that the environment can have so many viruses. "
" in the new source of agricultural products wholesale market environment detected a wide range of positive specimens, really give us some tips: the virus has been in the country for some time. If only for a short time, there may not be such a large pollution range. Of course, more data is needed to prove it. Zhang Yong, assistant director of the Viral Disease Institute, said.
to determine the time of the virus epidemic, the current main approach is genomic epidemiology. "First of all, the whole genome of the virus sequencing, sequencing after the use of bio-information analysis methods, put different viruses together to see which virus mutation more, change more is generally an evolutionary updated virus, mutation less closer to the original virus, it is more popular earlier, older." Of course, these are popular sayings. In addition, there are some specific algorithms that are calculated by mathematical models. Liu Jun said.
" from the preliminary results of genomic epidemiology, the virus is from Europe, but it is different from the current virus in Europe, it is older than the current virus in Europe. "As for how did the virus get in?" "There are several possibilities involved in this, " Zhang said. For example, the virus lurks in imported frozen food, from abroad to the whole storage, transport period, the virus because frozen did not evolve, so it will not mutate;
While the path of transmission of the virus has yet to be confirmed or proven, the initial hypothesization of genomic epidemiology may provide useful ideas for a combination of epidemiological investigations, big data techniques, etc. to solve the mystery of the source of the virus in new places." Streaming and big data can find a link between cases, and sometimes it's impossible to tell who's infecting them. Through laboratory testing and gene sequence analysis, we can know the path of transmission between them. And when we speculate on the possible transmission relationship between viruses, we can further look for evidence through such methods as flow. With the support of major national science and technology projects, the Viral Disease Institute is taking the lead in preparing a nationwide networked virus surveillance and traceability technology system based on the whole genome of the virus to deal with the major problem of virus tracing, which is related to the prevention and control of viral diseases related to national security. Zhang Yong said.
an old virus that is endemic in Europe, how on earth was it brought to the wholesale market of agricultural products in Beijing's Xinfazi? Scientists are still exploring day and night.