In 2009, Zhong Yang (left), a professor at Fudan University's School of Life, and Zhao Guoping (right), an academician of China Academy of Sciences, visited the 22nd Wen Hui Lecture Hall "Competition between Human Beings and Influenza".
When SARS just spread from Guangdong to other parts of the world via Hong Kong, scientists in Singapore divided SARS coronavirus into two genotypes according to the limited differences in its gene sequence. From the epidemiological point of view, one branch is related to Guangdong and the other is related to patient A who went to Hong Kong from Guangzhou.
How to Open the Black Box of SARS
Regarding infectious diseases in Guangdong and Guangzhou, the Centers for Disease Control and Prevention (CDC) in Guangdong and Guangzhou have done two very good jobs since the early discovery of SARS. The first is to make a very detailed epidemiological record of each of all transmission chains.
Each patient has an extremely detailed personal medical history record and transmission relationship record. The second is to collect biological samples of these people. We took out samples of these people, sequenced the whole genome of the virus, combined with detailed epidemiological data, conducted molecular epidemiological analysis, and finally opened the "black box" of early, middle and late SARS, and saw where it came from and where it would go.
Become a "phenomenal communicator" overnight.
At the beginning of the outbreak of SARS, it seems that the virus transmission ability is not very strong. In densely populated cities, too much contact with animals (such as wildlife markets) or "getting together" activities (such as playing cards in the basement all night) are important reasons for early onset. Since then, hospital infection has become an important way. An important case is that when SARS broke out in the Second Hospital of Zhongshan, Guangzhou, none of the infected medical staff transmitted it to their families, because they took the initiative to isolate and treat the symptoms as soon as they found them, and did not go home. The only exception is a nursing worker in the Second Hospital of Sun Yat-sen, whose job is to take some outpatients to the Department of Nephrology for hospitalization. Due to lack of medical knowledge, she did not go to the hospital for isolation in time after the symptoms appeared, and she was still working, so she was handed over to a nephrologist, who was later closely related to the spread of Hong Kong. After patient A arrived in Hong Kong, she went shopping everywhere during the day, but she didn't infect anyone. That night, I stayed in Room 9 1 1 of Jinghua Hotel. It was everywhere he went that night, including the elevator he took. After he came out, the second man went in and caught him. Nine people were infected that night, and then they brought SARS to Singapore, Canada, Germany, Frankfurt and other parts of the world.
The phenomenon that the disease spread strongly in such a short time occurred many times during the SARS epidemic, and it was called "super communicator" or "super communication event". Although the causes of this phenomenon include virus variation, individual differences between hosts (patients) and other social and living environment factors related to patients, we can still get interesting lessons from the analysis of molecular epidemiology.
Virus variation is not very clear and predictable.
The same patient A is a doctor. Before going to Hong Kong, he got typical pneumonia. After taking antibiotics, he recovered and his fever dropped. The nurse was very ill and was discharged in two weeks without complicated treatment. However, genome sequencing showed that there were some obvious and stable mutations in SARS coronavirus after being treated by Dr. A. Since then, few important amino acid mutations have been detected in viruses that spread from Hong Kong to other parts of the world. So far, all the viruses detected in the world belong to this same type, and from the perspective of phenotype and pathogenicity, this is indeed a particularly pathogenic human coronavirus. Although the genomes of viruses isolated from a hospital in Hong Kong have been greatly deleted since June, the pathogenicity of these viruses does not seem to be weakened. All these phenomena show that the variation of virus pathogenicity is often not very clear and predictable; However, if the virus spreads repeatedly in the human body, it is possible that in a short period of time, the virus with weak pathogenicity or transmission will evolve into a more toxic type, thus producing a disease epidemic.
Live interaction
There is no scientific basis for the conspiracy theory that a country deliberately creates virus harm.
Q: During the SARS in 2003, because all the people infected were Asians, some people wondered if other countries had deliberately created some kind of virus to infect us. Is there any basis for this view?
Zhao Guoping: That's a good question. People have said this for a long time, but so far, we still can't see that it is intentional. In addition, it cannot be said that SARS only infects Asians. The first case found in Vietnam was a westerner, who was a scientist. Therefore, I can't see that SARS is man-made.
Now, SARS virus has also been found in a bat, which further proves the natural source of this virus. There is one more important point. The really important breeding ground of SARS is the vegetable market selling wild animals in Guangdong. Because there are all kinds of animals there, not only civet cats, but also other animals found SARS virus. Therefore, the wildlife market may be a place to help the virus accelerate its evolution. Unfortunately, the receptors of civets are very similar to those of humans. Once the virus has adapted to civet cats, it has a very strong ability to infect people. Especially now that civets have been raised, the chances of infection have increased, which is divorced from the original wild ecological conditions-artificial captivity, not eating fruits and corn, and running into crowded environments. So I think it's still a natural change process, and the virus has more adaptation requirements and conditions in the crowded environment of the host (or potential host).
No vaccine can prevent all influenza viruses.
Question: There are 9 kinds of N and 16 kinds of H in the influenza virus sequence. Can we use computational biology to establish a vaccine bank, and once a new virus is found to cause disease, we can use the vaccine bank to stop the spread of the disease?
Zhao Guoping: As for vaccines, in fact, the vaccines used all over the world are a kind of recombination vaccines. When a new virus is found to be prevalent, for example, the new antigen genes of H 1N 1 and H 1N 1 replace the HA and n a genes of the original vaccine strain, so that a new vaccine can be made quickly. Now it is reported that a new A_H 1N 1 vaccine can be produced in August. However, it is not feasible to cultivate a vaccine that is immune to all influenza viruses. There are two kinds of antibodies, one is protective and the other is recognizable. But it has no protective effect. The reason why the virus is so powerful is that it will produce some mutations, so that the original protective antibody will no longer know the new virus and become unprotected. At present, there are antibodies against influenza virus in human body, but these antibodies do not know the antigen of this new virus A (H 1N 1). (finishing: Li Lian)
(Academician Zhao Guoping's identity at that time was: Executive Director of the Southern Research Center of the National Human Genome, who had presided over the molecular epidemiological research of SARS in China; Director of Department of Microbiology and Microbial Engineering, School of Life, Fudan University; Professor Zhong Yang (died in a car accident in Inner Mongolia on September 25th, 20 17, and was awarded the title of "model of the times" by the Propaganda Department of the CPC in April 20th18), a 45-year-old professor at the School of Life, Fudan University, spent three years translating the book Epidemic-Epic of Death and Plague. )
Pandemic influenza--zhong yang's death plague epic.
Follow-up report:
Academician Zhao Guoping's Talk on No Serious Disease of Influenza A in 2009
Zhong Yang: Scientists race against the flu, and the public should learn to dance with the flu.
Zhao guoping and zhong yang: can the outbreak of influenza be accurately predicted?
Link at the end of the article:
Zhao Qizheng recalled SARS: the distance between people became larger, and the distance between hearts became smaller.
Interview with Bei Tang: Looking at the beginning and end of international cooperation in epidemic prevention and control in China from the first five cases of PHEIC | Dialogue with epidemic prevention experts.
Visit to Peng Kaiping: Normal stress reaction, turning "depression" into opportunity in fighting epidemic situation | Talking about epidemic prevention experts.
Interview with Guo Qiyong: Should we eat wild animals? Regain the wisdom of "harmony between man and nature" | Experts talk about epidemic prevention
Author: Zhao Guoping Wen Hui Lecture Hall
Scene photo: Zhou Wenqiang