The article is from the public number: CC Weekly (ID: cancer-weekly) , author: Catcher (famous science scholar), the original title:” The new understanding new crown virus: National “Stop-off” epidemic prevention is not sustainable.

I. How to overcome the epidemic situation of New Crown virus? Some backgrounds you must know

1. Start a picture

(The picture above is a map of common epidemic data released by the New York Times when it reports the new coronavirus)

As we all know, to evaluate the threat of a virus, we look at two aspects: one is “toxicity”, which mainly includes the “fatality rate” and “severe disease rate” indicators; the other is “infectiousness”, which mainly includes ” Basic infection number R0 “indicator. This is the case for the vertical and horizontal coordinates of the above figure. Therefore, we are now evaluating the new crown virus. In simple terms, we need to give the new crown virus an accurate “location” in the picture above.

The data we rely on is the daily epidemic report of the National Health Commission and the Hubei Health Commission since the official announcement of the epidemic on January 20. As of February 16, exactly 4 weeks of data. As shown below:

(Note: In the data released by the Hubei Health and Medical Commission, the number of “severe cases” on January 25 is wrong. The red numbers in the figure are modified by the author. Valuation.)

2. Two reference objects:

SARS in 2003 and H1N1 in 2009 (ie “swine flu” in Figure 1) . Need to find SARS to benchmark this needless to say, some people may think, why still look for a stream H1N1? Because H1N1 is not the common flu (we often say the flu refers to the “seasonal flu” in the picture above) , but in A global epidemic broke out in 2009, including China.

Or put it this way: In the past two decades, the three major epidemic outbreaks in China are: SARS in 2003, Influenza A in 2009, and New Crown Virus in 2020.

The three virus outbreaks are as follows:

(Note: SARS data comes from WHO, A-stream data comes from the Social Statistics Yearbook of the National Bureau of Statistics 2009)

3. The data of Hubei, especially Wuhan and other provinces are very different

The root cause is described in detail below. It is because of the severe consequences of the epidemic in Hubei, especially While the virus was not caused by the virus itself, but rather caused by the near-paralysis of the medical system caused by the virus outbreak. Secondary disasters “. The “secondary disaster” is greater than the “primary disaster” of the virus, which is characteristic of Hubei and Wuhan this time. Therefore, when we want to study the characteristics of the virus, we need to exclude Hubei data and only look at the situation in other provinces. After all, there are already more than 12,000 patients in other provinces, which is enough.

Second, our collective fear of the new crown virus may be wrong

Our fear of the new crown virus comes from the data in Wuhan and the initial target of SARS—we fear that another SARS-like infectious disease has occurred and the number of people infected and killed is more than SARS. Several times! However, if you look at the data from other provinces that can better reflect the actual situation of the virus, you will find that the new crown virus is more similar to influenza A; and because of the strict national epidemic prevention measures, there is no “outbreak” epidemic situation in other provinces!

  • Case fatality rate: As shown in Figure 3, after the entire epidemic, the case fatality rate of SARS is 6.55%; the flu rate is 0.54%; the new crown virus epidemic has not ended, and the crude case fatality rate is currently 0.6%. If we expect a 14-day delay in patient treatment time, the probability of a dynamic case fatality rate is between 0.5-1%, which is about twice the rate of flu.

    • Severe illness rate and severe case fatality rate: As shown in Figure 3, we only compare Alice and New Crown The rate of severe illness of the virus is about twice as high as that of the new crown virus. (13% vs 6.85%) , but the rate of severe death of the new crown virus 2 times more (8.74% vs. 3.9%) . This is very consistent with recent reports that the rescue of severe patients with new crown virus is very difficult. Popularly speaking, compared with influenza A, the new crown virus is not prone to severe illness; but if it is severe, treatment and rescue is difficult.

      • The basic number of people infected R0: Scholars generally think that the R0 of SARS is between 2-3; the R0 of the first class is about 1.2; The R0 of New Coronavirus is currently generally considered to exceed SARS. Various models are estimated to be between 3-6, and China CDC has recently analyzed more than 9,000 samples and believes that the R0 value of New Coronavirus is as high as 3.77. This is the first class 3 times! In particular, some scholars have found that from the perspective of the mechanism of the virus, the affinity of human ACE2 protein and the new coronavirus is 10 to 20 times that of SARS virus!

        • Incidence: As shown in Figure 3, SARS was mainly Beijing and Guangdong in that year, not The national epidemic situation, so its incidence rate is 0.4 cases per 100,000; and A flu is a national epidemic situation, the incidence rate is 9.17 cases per 100,000; now the incidence rate of New Coronavirus outside the province is 0.92 cases per 100,000-incidence The rate is only 1/10 of the national outbreak! Of course, this is entirely due to the strict “isolation” and “blocking” of epidemic prevention in other provinces during this period. Otherwise, with its 3 times the infectivity of the flu, the incidence will be much higher than the flu!

          Through the above analysis, we can draw an accurate map of the new crown virus. As follows:

          From the map of the new crown virus, we need to have some objective understanding of it:

          First, the new crown virus is not flu. (seasonal flu) , it is much more serious than flu!

          New crown virus is 3-5 times more infectious than influenza, and its fatality rate is 5-10 times that of influenza; overall, its harm is about 15-50 times that of influenza! Therefore, we must not take it lightly and mistakenly think that the new crown virus is similar to the flu and relax our vigilance.

          Second, the biggest threat of New Crown virus lies in its super infectivity!

          It is more than three times more contagious than Aquarium, and it is far more than SARS. Because of its high contagion, a large number of people were infected for medical treatment, crushing medical resources in a large city like Wuhan, and generating more “secondary disasters”.

          Third, in the case of infectious diseases, the case fatality rate of new crown virus is not high, which is about twice that of influenza A, but far lower than SARS.

          Fourth, there are fewer patients with new crown virus, but it is difficult to cure them!

          This reminds us, To reduce the case fatality rate of new coronavirus, we must screen and diagnose as early as possible, and then intervene and treat in time in the early mild stage to prevent it from reaching the severe stage! The word “quick” is the weapon of the other’s new crown virus infection!

          Summary: The best benchmark sample for the new crown virus is H1N1.

          Comparison of the two, its infectivity is about 3 times that of influenza A, and its mortality rate is about 2 times that of influenza A. The new crown virus is not very toxic, but its infectivity is very strong. The new crown virus is in Hubei, especially The severe epidemic in Wuhan was mainly caused by its super infectiousness.

          Three, provinces: lowering R0 below 1 is victory

          “Shock” epidemic prevention is not sustainable!

          Compared with the severe epidemic situation in Hubei and Wuhan, the situation in other provinces is much better: the national morbidity rate in other provinces is 1/300 in Wuhan, and the case fatality rate is 1/5 in Wuhan after the onset. The risk of lethal new crown virus infection is only 1/1500 of that of Wuhan, which is so small that it is almost negligible.

          Comparison 2009The outbreak of influenza A in the whole country in 1976 can better explain the problem: the transmission rate of the new crown virus itself is more than three times that of the influenza A, but the incidence of the new crown virus in other provinces is only 1/10 of the influenza A!

          The achievements of other provinces in the prevention and control of the new crown virus epidemic are based on the implementation of a “first-level response” system almost everywhere. In the past month, factory shutdowns, school suspensions, road blockages, and a significant reduction in residents’ outings have resulted in a level of strict “shock-like” prevention and control measures that have yielded amazing results.

          However, this “shock-type” prevention and control has a large social cost and will never last. And now it ’s time for us to think about it:

          First, when will the provinces return to normal? Are there any indicators to judge that it can return to normal?

          As of the data on February 17th, there were less than 100 new patients in all provinces on that day! Is this still not fully restored? If this indicator doesn’t work, what indicator to look at? Is it necessary that the number of newly added patients on the same day in other provinces is zero in order to fully restore the order of production and life?

          Second, can other provinces completely eliminate the new crown virus?

          I deeply doubt it. Because of the low toxicity of the new coronavirus, this makes it easier to symbiotic with the host (Human body) for a long period of time without any symptoms, but Nor does it lose its contagion. In the face of such a virus, it is very difficult and almost impossible to imagine the complete extinction of the other person’s SARS virus. Attempting to mobilize the whole society to fight a new crown of virus “annihilation war” may be futile. For human beings, we must be well prepared for the long-term coexistence with the new crown virus, and a long-term “protracted war”!

          Third, for the health and epidemic prevention departments, as long as the number of basic infections R0 of the new crown virus is below 1, the virus cannot break out, which is a victory for epidemic prevention!

          Let’s take the example of Beijing: Beijing is under strict control. About 7% of close contacts of currently diagnosed patients are later found to be infected with the new crown virus. This means that under the current control measures, the R0 of the new crown virus must reach 15 or more before it can erupt in Beijing. In other words, it is a confirmed patient in Beijing. If the close contact population does not exceed 15 people, then the virus cannot erupt in Beijing.

          From this point of view, when we take the objective of “reducing R0 below 1” to prevent epidemics, we can completely restore normal production and living order, and at the same time:

          (1) It is free to send out hot consultation. Encourage the public to go to the hospital immediately.

          (2) Screening and isolating confirmed patients, suspected patients, and even fever patients as soon as possible can greatly reduce close contact with the population.

          (3) For confirmed patients, regardless of the severity, start antiviral therapy as soon as possible. Such as clinical use of chloroquine, which appears to be more effective.

          (4) Educate the public on personal hygiene and reduce close contact with others.

          Fourth, the “annihilation war” encircled by the city, the social cost is unbearable

          Summarize the main points of this article:

          1. The biggest threat of New Crown virus is its very rapid infectivity. “Fast” is the biggest weapon of the new crown virus!

          2. The “toxicity” of the new crown virus itself is not great. The situation in Hubei, especially Wuhan, was mainly caused by the “secondary disaster” after the virus caused the medical system to collapse.

          3. With the complete elimination of the new crown virus as the target of the “epidemic” of war, the “annihilation war” enclosed by the city will be very costly and may not be achieved; instead, R0 is reduced to 1As the target of the “epidemic” of war, the “protracted war” of comprehensive restoration of normal production and life is most feasible.

          4. To win the epidemic, the key lies in “quick”! As long as we achieve “quick screening and rapid isolation”, we can maintain normal order of production and life, and the virus will not erupt!

          5. Potentially effective antiviral drugs such as chloroquine and radesiver continue to enter the clinic, making individuals’ risks significantly reduced in the event of infection with the new crown virus.

          The article is from the public number: CC Weekly (ID: cancer-weekly) , author: Catcher (famous science scholar).