This article comes from span> public micro-channel number: a seat (yixiclub) span> , author: Shi Zhengli, a researcher at the Wuhan Institute of Virology, Chinese Academy of Sciences, originally published on July 31, 2018. span> p>
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Whether it is south or north, central or west, we will go wherever we hear that there are bats, and we have footprints in 28 provinces and cities in our country, like a needle in a haystack. This is done for more than ten years. p> blockquote>
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Hello everyone, I am from Wuhan Institute of Virology, Chinese Academy of Sciences, and my name is Shi Zhengli. Today, I am very happy to tell you the story of tracking the source of SARS. p>
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SARS is the English abbreviation for Severe Acute Respiratory Syndrome. It is also called atypical pneumonia in China, and it is also called “SARS” for short. p>
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In 2002 and 2003, the first outbreak of SARS in Guangdong, China, spread to 27 countries and regions in the world in just 5 months, causing 8,000 infections and nearly 800 deaths. This century The most serious infectious disease at the beginning. p>
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But it’s been 15 years since SARS, why do we still tell the story of SARS? This is because in the scientific community and the public, there are still some puzzles that have not been solved. Where does the pathogen of SARS come from? Will similar diseases occur? How can humans prevent such diseases? p>
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Let’s briefly review the history of the SARS outbreak. The first SARS case occurred in Foshan, Guangdong. From November 26, 2002 to January 2003, 11 cases occurred in different places in Guangdong Province. p>
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They showed similar clinical symptoms: fever, cough, dyspnea, chest radiograph showing shadows of both lungs, and some patients had respiratory failure. Unfortunately, the use of various antibiotics against bacterial infections has not worked. p>
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Experts call this unknown cause an atypical pneumonia. Some of the earliest contacts with SARS patients, such as relatives, doctors and nurses, quickly became ill. p>
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At the end of February 2003, a nephrologist from Guangzhou went to Hong Kong to attend a relative’s wedding and stayed at the King Wah Hotel in Kowloon. At the same time, an American businessman, a couple from Toronto, Canada, and three Singapore tourists also stayed on the same floor of the hotel. p>
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The doctor didn’t realize he was infected with SARS. After arriving in Hong Kong, he was quickly admitted to the hospital. After leaving Hong Kong, several other residents were admitted to hospitals in Hanoi, Toronto, and Singapore. SARS outbreaks have occurred in these countries and regions. p>
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On March 15, 2003, the World Health Organization issued an emergency travel alert to the world, asking everyone not to travel to China. All trades, all contacts can stop. p>
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Around the Spring Festival in 2003, SARS began to spread from Guangdong to the wholeContinue to do. If we continue, our research strategy must be changed. Just then the laboratory next door was doing SARS virus antibody detection. We wonder if we can first find out which bat populations have been infected by SARS. If antibodies are found, then narrow down the scope and find the source of the SARS virus. p>
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Results We found antibodies to SARS virus in the three bats of Guangxi and Hubei, and we detected coronavirus in these three bats. Because it belongs to the same species as SARS virus in taxonomy, we call it bat SARS-like coronavirus. p>
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This gain was quickly published in the 2005 issue of Science. This work can be said to be an important milestone in our search for the source of SARS. It guided and supported our hypothesis, explaining Bats are indeed related to the source of SARS. Strong> p>
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But after a careful comparison, we found that the bat SARS-like coronavirus and SARS virus discovered in 2005 still have some differences, especially the one key gene that determines the viral infectivity and pathogenicity is different. For example, it is a relative of the SARS virus, but it is not an immediate relative and cannot infect people. So we have to continue this work. p>
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In the next few years, we continued to find all over the country, because there is no target and we do n’t know where it is located. No matter whether it is south or north, central or west, we will go wherever we hear that there are bats, and our footprints are all over China’s 28 provinces and cities are like needles in a haystack. This is done for more than ten years. p>
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Everyone may ask, what kind of experience is this scientific research work you go to collect bats every day? First of course, it is very difficult. Bat caves are generally in remote places and the terrain is more dangerous. We usually find some local guides familiar with the terrain. p>
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A lot of times there is no road, we have to go over the mountains and cross the mountains, and make our own way. Sometimes the bat cave is on a mountain not far away, and the straight line distance is not more than tens of meters. It takes several hours to walk over. Sometimes the bat cave is very large, but the hole is very small, so you have to crawl into it. p>
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This kind of work has requirements for the physical fitness of our team members, including their body shape, otherwise they will not be able to climb in. Over the years, we have also gained the ability to climb and drill holes. p>
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Because bats are nocturnal animals, we sample to get up early and greedy. Before dark, the bird netting was set up at the entrance of the cave. When the bats flew out of the hole for food, some would hit the net. p>
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Then we removed the bat from the Internet and collected swab samples overnight. If there are a lot of bats harvested, they will often work until one or two in the morning, and they will be released after taking a sample. p>
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The next morning when the day is not bright, we need to enter the hole again to collect fresh bat droppings. p>
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Some friends may think that we are sampling to deal with terrible viruses, a bit of a biochemical battle, just like the picture on the left. But this job is not as dangerous as everyone thinks. Although bats carry a lot of viruses, the chance of directly infecting people is very small. Unless we know that bats in a certain location carry viruses that can spread to humans, they will take a higher level of protection, and in most cases only ordinary protection. p>
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Another benefit of the sampling is that because the places where the bats are staying are very quiet places, the mountains and rivers are beautiful, and it also gives us the opportunity to enjoy a lot of great rivers and mountains. Zhangjiajie, Guilin, Xishuangbanna … The furthest I have been to Nyingchi, Yarlung Zangbo River in Tibet, and there are many unknown places along the way. p>
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By 2011, we had new clues: We isolated and detected a bat SARS-like coronavirus that is highly homologous to SARS virus in a hole in Yunnan, which can be said to be an immediate family member of SARS. In addition to the close evolutionary relationship, they are also very similar in function. p>
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In 2013, we successfully isolated a virus from a sample of this hole. It is closer to the SARS virus than all bat SARS-like coronaviruses found in the past. The most important thing is that it can infect humans and other mammals. Animal cells. The discovery, published in the journal Nature, is a very powerful piece of evidence that SARS originated in bats. p>
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We have continued to monitor the cave for five years and take samples twice a year. As a result, more than ten different types of SARS-like coronavirus have been found. Although no virus exactly the same as SARS virus was found, we found a natural gene bank of SARS virus. It can be understood that if we compare the SARS virus to a building block, then all the modules that make up the building block are found in this hole. p>
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Subsequent bioinformatics analysis, we proved that SARS virus isRecombinant S-like coronavirus strong>. At the end of 2017, we published the latest research results. p>
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After 13 years of tracking, we finally determined the bat origin of the SARS virus. But when SARS broke out in Guangdong, the virus we found was in Yunnan. How did it pass? p>
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In fact, before the SARS outbreak, most of the civet cats raised in many parts of China were sold to Guangdong. We speculate that the bat SARS-like coronavirus accidentally infected civets in Yunnan farms, and the infected civets were subsequently sold to Guangdong. The virus spread further in the civet on the market, constantly mutating, and eventually produced a highly transmitted SARS virus that infected humans. p>
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Since bats are the culprits of SARS, have civets been wronged? Neither is it. Although the root of SARS is not in civet, after all, it is a direct source of SARS virus in humans. strong> p>
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Although SARS has not made a comeback for so many years, in nature, this virus similar to SARS still exists. If we humans are not alert, the next virus infection may be a direct infection, or it may infect humans through other animals. This possibility is entirely present. p>
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Everyone will find that new infectious diseases have appeared more and more frequently in the world in recent years. In addition to SARS and Hendra and Nipah virus mentioned just now, there are H7N9 bird flu and Ebo that you are familiar with Latin America, Middle East Respiratory Syndrome, etc. These emerging infectious diseases all have a characteristic, they are all related to animals. Researchers have done statistics, and more than 70% of new infectious diseases originate from animals. p>
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In fact, these viruses do not come out now. They often have evolved with natural hosts for many, many years, ranging from decades to hundreds of years, even tens of thousands of years. This virus is not directed at us, it is constantly multiplying for our own survival. p>
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So how did these wild animals and vector viruses reach human society? There were n’t so many infectious diseases in the past. Why are there so many now? p>
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Let’s see how SARS comes from. The source of SARS is that bats are not fake, but the stage where it develops is the Guangdong wildlife market and restaurants. strong> If we do n’t abuse and eat civet, then the transmission chain of the virus from bat to civet to human will not happen, and SARS will not erupt that year. p>
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Look at how Ebola came from. In Africa, wildlife is one of the carnivorous sources, especially in rural areas, where orangutans, monkeys and bats are their main hunting targets. In this way, the Ebola virus repeatedly went from the jungle to the village and finally to the city. p>
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Look at how the Nipah virus in Malaysia infected humans. The range of human activities has accelerated and has continued to penetrate into the habitats of wild animals. We built the pig farm next to the bat habitat. The bats ate fruit. The fruit was contaminated by the virus and fell into the pigpen. After eating, the pig became ill and infected the virus. p>
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Whether it is edible wild animals or human beings ’erosion of the territory of wild animals, these have greatly increased the contact between humans and animals, and created conditions for the virus to spread from wild animals to humans. Coupled with the rapid development of globalization and convenient transportation, infectious diseases can soon be transmitted from a small village to the world. Therefore, it is not an incident in a village or a region. It is a public health issue of global concern. p>
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So it’s actually very simple to prevent new infectious diseases from the source, just stay away from it. We must eliminate wildlife consumption and reduce intrusions into wildlife habitats, and we humans must stay away from wildlife. p>
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Some people think that engaging in eco-tourism and intimate contact with wildlife is the harmony between man and nature, but this is not the case. The real harmonious coexistence is that you don’t disturb nature and let them live well. p>
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And our domestic animals, such as our farms, should try to keep away from wild animals and avoid close contact.
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Back to the bat, it is indeed a very powerful animal, carrying so many viruses, including a powerful virus that is fatal to humans, but never develops the disease itself. What’s special about bat’s immune system? This is also a research direction that scientists are very interested in. However, this research direction is only in its infancy, so it will not be discussed in detail here. p>
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I want to tell you that we don’t have to panic too much about the virus on bats. As long as you keep a certain distance from the bat, the chance of the virus spreading to people is very small. p>
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On the other hand, bats occupy a very important position in the ecosystem. Insect-eating bats are natural enemies of pests, and fruit-eating bats are the spreaders of seeds and pollen. They contribute to the maintenance of ecological balance. We ca n’t because bats carry viruses.Negate the credit for it. p>
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If bats are wiped out for the crime of spreading disease, the entire ecosystem will suffer immeasurable losses. Therefore, I have always advocated non-invasive sampling of bats: the samples are mainly collected from feces and swabs, and the bats are returned to nature after sampling. p>
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Actually, bat SARS-like coronavirus is just one of our many research subjects. We are also conducting similar surveillance research on other viruses in bats, mice, and domestic animals. Like hunters, we will find and search for viruses that these animals may transmit to humans, and find hot spots where new infectious diseases may appear. And carry out key monitoring to provide information for the prevention and early warning of new infectious diseases. p>
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We tell people where the disease may occur, what animals may spread the disease, and then we work with the health department to guide everyone to prevent and control the virus from the source, and find them before they find us. This is also the purpose and significance of our virus traceability and virus surveillance research. p>
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Thank you all. p>
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This article comes from span> public micro-channel number: a seat (yixiclub) span> , author: Shi Zhengli is a researcher at Wuhan Institute of Virology, Chinese Academy of Sciences. The copyright of this article belongs to one seat and the speaker, please reprint or quote text and pictures, please contact a seat. span> p>