At present, the situation of epidemic prevention and control in China continues to improve, and foreign epidemics spread rapidly. "External defense input and internal defense rebound" has become the focus of epidemic prevention and control in China. Can I take off my mask now? How contagious are asymptomatic infected people and relapsing patients? Will pets spread viruses? Recently, Zhong Nanshan, an academician of China Academy of Engineering, responded to the hot issues of epidemic prevention and control.
It’s not time to take off the mask yet.
Zhong Nanshan:At present, the situation at home and abroad is very different. China has entered the second stage of the epidemic because of its decisive measures, while other major countries are still in the first stage of the outbreak and are still climbing up. This means that the probability of human-to-human transmission is very high, and the number of confirmed cases increases very quickly.Wearing a mask is still an important means of self-protection, but it is not necessary to wear it in areas where the epidemic situation is not serious, places with few people or open spaces.
Wuhan has passed the customs, but there is still the next pass.
Zhong Nanshan:After the outbreak, the central government took decisive measures to control Wuhan’s urban traffic, and it was very successful to take measures to prevent and treat it in other places. In the history of epidemic prevention and control, this is also a feat. However, there are still two tests: one is how to prevent and control while returning to work, and the other is the "external defense input" barrier.At present, foreign epidemic situation is still at the peak, and some coastal cities in China, which have close communication with foreign countries, are easily "involved", and then some epidemic situations occur.It can be said that the next "pass" of Wuhan is also the "pass" of the whole country, and it needs to pass through various prevention and control measures.
3. It is very unlikely that foreign imports will cause a second outbreak in China.
Zhong Nanshan:There are actually two questions about whether the overseas epidemic will cause a second outbreak of the domestic epidemic: first, whether the imported cases have spread, and second, whether they will break out in the process of spreading. The risk of transmission of imported cases definitely exists, especially cases with positive nucleic acid test or symptoms of infection, which are highly contagious and will cause virus transmission. At present, the mass prevention and control in China has been sinking into the community, and community residents have a strong sense of self-protection, such as wearing masks and keeping a distance from others. Once someone has symptoms such as fever, he can report or accept diagnosis quickly, and then isolate.On the whole, the risk of community transmission certainly exists, but the probability of the second wave of outbreaks in China is very small.
It is too early to talk about the "turning point" of the global epidemic.
Zhong Nanshan:Globally, the original "epicenter" of the epidemic was in Europe, especially Spain and Italy, and now it also includes Germany, France and Britain.The biggest problem at present is the United States. In the past week, the number of confirmed cases in the United States has increased at a rate of 10,000 to 20,000 per day. It is too early to predict when the global epidemic will have an "inflection point".It can be said that whether there can be an "inflection point" mainly depends on whether governments can intervene strongly. There are many unpredictable factors in other countries. According to the current situation, I am afraid it will take another two weeks.
5. The proportion of asymptomatic infected people in China will not be large.
Zhong Nanshan:Asymptomatic infected people do not appear out of thin air, but usually appear in two groups: first, people who have not shown symptoms for the time being but may have been infected in areas with relatively serious epidemics; The other is the close contacts of the confirmed cases, and their proportion is relatively small. Asymptomatic infected people also have two concepts. One is that they have no symptoms at first, but then they will gradually develop into symptoms. Such patients are definitely contagious; The other is that during a long observation, there is no symptom all the time, but the nucleic acid test is positive. We are studying the infectivity of such patients.However, according to the characteristics of Covid-19, once symptoms appear, it is more contagious, so it is correct to isolate asymptomatic infected people for observation.
6. Most patients with relapse are not contagious.
Zhong Nanshan:Generally speaking, most patients with relapse are not contagious. Most of the so-called multiple positives are fragments of nucleic acid, not the virus itself.We need to pay attention to two situations. The first is whether the patient has a relapse. If the patient produces strong antibodies, he will not be infected again. As for whether patients with relapsing yang will be transmitted to others, it needs specific analysis. Generally speaking, nucleic acid fragments are not contagious. Some scholars have cultivated throat swabs and secretions of patients with relapsing yang, but they have not cultivated viruses. The second situation is that patients have many basic diseases, but their symptoms have improved and they have not fully recovered. These patients cannot rule out infectivity.
7. There is not enough evidence of "influenza" in COVID-19.
Zhong Nanshan:At present, there is not enough evidence of COVID-19’s "influenza".Unless there is such a rule in virus transmission: its infectivity is still strong, but the mortality rate is getting lower and lower. In this case, it is possible to exist for a long time. We now need to make long-term observation and master sufficient data and cases before we can draw such a view. Under the present circumstances, I don’t think this prediction will come true.
8. It is too early to draw conclusions about animal-to-animal transmission.
Zhong Nanshan:It remains to be seen whether some animals such as dogs, cats and tigers are positive for nucleic acid detection, which is caused by pollution or infection. Some animals originally carry some viruses, which may not be symptomatic or contagious.It is too early to conclude that Covid-19 in these animals can infect both humans and animals, and both can cause diseases.
9. Some effective drugs have been found, but there is no specific drug yet.
Zhong Nanshan:Some drugs we are testing now (such as chloroquine phosphate) are definitely effective. We are summarizing them and will announce them soon. There are also some Chinese medicines (such as Lianhua Qingwen), which we have not only done in vitro experiments, but also found in P3 laboratory (the third-level laboratory of biosafety protection) that their antiviral effect is not strong, but their anti-inflammatory performance is outstanding, and the relevant experimental results will be published soon. In addition, there is Xuebijing, a traditional Chinese medicine. Its main components include safflower, salvia miltiorrhiza, radix paeoniae rubra, etc. It is used to promote blood circulation and remove blood stasis, but it is also effective in the treatment of severe patients. We are summarizing the situation of these drugs.
10. The vaccine will not be on the market soon, and the vaccination depends on the situation.
Zhong Nanshan:Vaccine is very important to really end the epidemic. Now all countries are developing it at the fastest speed, but I don’t think it can be made in three or four months. In addition, according to the experience of fighting SARS, removing the intermediate host can also block the spread of the epidemic. At present, we are not clear about the transmission chain in Covid-19, and it is also important to cut it off after it is clear.Put all your hopes on the vaccine, and all other methods are negative. Moreover, after the vaccine comes out, it is impossible to be perfect at once. The susceptible population can be vaccinated, but it is not necessary for everyone to be vaccinated.
11. Group immunization is the most negative practice.
Zhong Nanshan:The most negative way to deal with the epidemic is the so-called "group immunity", which was the idea more than 100 years ago.At that time, human beings had no choice but to let the virus infect them, and those who survived the infection naturally got antibodies. I don’t agree to deal with Covid-19 in this way again. In the past 100 years, mankind has made great progress, and there are many ways to prevent it, so there is no need to use natural immunity or group immunity.
12. The most worth sharing experience of the "epidemic" in China War is execution.
Zhong Nanshan:China War "epidemic" mainly took two measures: first, blocked the outbreak area and blocked the spread; The second is grassroots group defense and group governance. Now there are two core points of prevention and control: one is to keep a distance, and the other is to wear a mask.
So,China’s most shareable experience is execution.. The medical level and technical strength of many countries are much higher than that of our country. The reason why we were caught off guard in the face of the epidemic was because we were not prepared mentally and did not take decisive measures, which led to the infection of many front-line medical personnel. Once this line of defense collapses, it is easy to get out of control.
(People’s Daily client)
