Virologist at the University of Hong Kong: Worst case scenario

As people who have been dealing with viruses for a long time, virologists are undoubtedly the group of people who are most familiar with viruses in the world. Virus scientists should have something to say about how the virus occurs, how it spreads, how the epidemic develops, and how to protect it.

From the perspective of Jin Dongyan, School of Biomedical Sciences, The University of Hong Kong, there are many debatable responses to the new coronavirus pneumonia epidemic in Wuhan. He said that as a virologist, the most important thing is to communicate openly with the public.

On December 31st, January 3rd, 5th, and 11th, Wuhan Municipal Health and Health Commission stated that no obvious human-to-human transmission and no medical staff infection were found; on January 15th, Wuhan Municipal Health and Health Commission stated that “not yet found Clear human-to-human evidence does not rule out the possibility of limited human-to-human transmission, but the risk of continued human-to-human transmission is low “; on January 20, Zhong Nanshan, the leader of the high-level expert group of the National Health and Medical Commission, said,” According to the current data, the new crown Viral pneumonia is sure to be passed down from person to person. “At 2 am on January 23, Wuhan announced that it would” close the city. “

In the past few days, in the face of swarms of seekers, the shortage of medical supplies has prompted major hospitals in Wuhan to launch fundraising activities. At the same time, military hospitals, Shanghai, Guangdong, Zhejiang, Guangxi, Beijing, Tianjin, Jiangsu, etc. The locality also organized a medical ambulance team to help Wuhan. So, how serious is the new coronavirus epidemic in Wuhan, how it will develop in the future, how to protect it at present, how to seek medical treatment, and what is the worst case scenario, in response to these problems, Jin Dongyan accepted an interview with “Intellectuals”.

What will happen to the epidemic?

“Intellectuals”: Now there are some studies that have speculated on the source of the virus. What do you think?

Jin Dongyan: In fact, the source of the virus is not the most important thing now. If evolutionary speaking, the original source of these viruses is bats, this is beyond doubt. So how do bats reach people?

For example, the MERS virus (Middle Eastern Respiratory Syndrome Coronavirus) in humans and bats is very similar, and it also infects camels. Camels are an intermediate storage host, and many people believe that the virus has adapted in camels. Many camels have, and then spread to people. Because camels in the Middle East are so important that it is impossible to kill them all, there have been cases of human infections from 2014 to the present. In other words, in the case of MERS, there is a stable host in the middle.

SARS virus is found in several wild animals such as civet, but the situation is different. Researchers have applied the MERS virus to camels, and camels have milder symptoms that have been experimentally studied. However, the SARS virus has not been inoculated into the civet, and the observation of the virus’ reproduction and how it is transmitted to humans is still a mystery and has not been explained clearly. Wild or captive civets have not found SARS virus in nature.

At present, in addition to the South China seafood market, the virus in Wuhan is the identified source, and other markets have problems. For example, a Hong Kong resident working as an accountant in the Baishazhou market was also infected, indicating that different wild animal markets are definitely high-risk places. But what kind of animal and how to pass it to people, through which intermediate host, is not the most important and urgent issue now, it is definitely to decisively cut off, ban wild animal breeding and trading, or even breeding, because it is just impossible Corrective. 

After comprehensively banning wild animal breeding, it is not easy to find out which animal is infected. This mystery is not easy to unravel. If this animal is only a transient or transient intermediate host, as in the case of the SARS virus infecting civet cats, then it may never be possible to reproduce the actual situation that once occurred in the South China Seafood Market or other wildlife markets.

The new coronavirus is most likely passed on to humans by some mammal as an intermediate host. Although the animal traceability of this virus is still worthy of research as an important scientific issue, at present animals are obviously no longer a source of infection, so discussing animal traceability is also an inconvenience for epidemic prevention.

“Intellectuals”: Will the virus pass directly from bats to people?

Jin Dongyan: Bats may pass Ebola virus directly to humans. Previous pandemics in Africa may have started when children came into contact with animals or their saliva or feces in tree holes where bats were hidden. Fruit bats are the main storage host for this virus, and humans may also become infected through contact with contaminated fruits in the forest. The outbreaks of Nipah virus in Malaysia and Singapore from 1998 to 1999 also originated from bats and can be directly transmitted to humans by bats.

Bats have a special immune system that makes them a reservoir for many viruses, including influenza, SARS, MERS, Ebola, etc. All rabies virus infections in the United States are caused by bats. Whether bats pass the new coronavirus directly to humans cannot be ruled out. It is also possible to pass the virus directly to humans during slaughter because of eating bats.

Wuhan University of Virology Professor Shi Zhengli has discovered that there are close relatives of the new coronavirus in bats. The virus may pass from bats to intermediate hosts and then to humans, and direct transmission cannot be completely ruled out. However, in the current epidemic, bats are no longer passed on directly or indirectly from bats to humans, but now they are definitely transmitted from person to person. The main problem is to solve the problem from person to person.

“Intellectuals”: Are there “super communicators” now?

Jin Dongyan: I still have reservations, I can’t say no. Now it is necessary to publish detailed patient information, which is helpful for the control of the epidemic and public education. If a patient infects more than a dozen medical personnel, one may be because the medical personnel did not take appropriate protective measures because they did not know, and the other may be the patient ’s viral load is extremely high, or two factors may work together . If this patient has a particularly high viral load and can transmit so many people, he is a super communicator. Is this the case? People who need to do epidemiological investigations need to clearly analyze the specific data in order to draw reasonable conclusions.

In fact, from an epidemiological point of view, many investigations have not been followed up or made public, and the situation has not been checked, and it has been turned over. Scholars who do epidemic prevention work should be selfless, and open or publish data important to epidemic prevention work as soon as possible.

“Intellectuals”: Is it easy to pass people from person to person?

Jin Dongyan: The virus was passed from animal to human in the first step, and then passed to the second generation of people. It is certain that both of them happened, and it was very effective for these people to pass on to the next generation of people. It must be able to pass on people, and it is very effective. But when these people passed to the 3rd and 4th generation, were they still so effective or weakened? There is still no clear answer at this point. It remains to be observed and studied. This is very important for the progress of the epidemic.

At present, most cases are still more or less directly and indirectly related to Wuhan. Basically, they can also be connected to Wuhan. In the future, for example, many people in Guangzhou who have never been to Wuhan are infected (now these people have, But rarely), it shows that the next transmission is also effective.

As far as SARS and MERS are concerned, the transmission power is weakened, and it will not be transmitted to the 4th and 5th generations equally effectively. If it is passed down again, it will not weaken, that is to say it has fully adapted to the human body.

“Intellectuals”: If the virus persists, what is the situation?

Jin Dongyan: There are four common human coronaviruses, which are called 229E, OC43, HKU1 and NL63. Among them, HKU1 and NL63 were discovered in follow-up research after SARS. These four viruses cause a common cold and are weaker than the flu. If these viruses are traceable, NL63 and 229E are also from bats, while OC43 and HKU1 may be from rodents. However, these four viruses are now very common in humans, but they only cause a common cold. But if you go back for decades, a hundred or two hundred years or more, when these viruses first entered the human body, they will be the same, and they will cause a global pandemic, which may be similar to the current situation of new coronaviruses or SARS, but What is the end result? It is all these viruses that have weakened to the point that they can only cause a common cold, which is a bottom line.

If it is indeed very strong in transmission, and it is very continuous, we ca n’t do a lot of things, and then it will be normal management. We will not seal the city because of a seasonal flu. That’s the kind of ending.

Coronaviruses have been weakened in history, and most other human viral pathogens have also been weakened. The better the virus spreads, the weaker it is, because if it kills everyone, it will not be good for the virus itself.

“The mortality rate is certainly not as high as SARS from now on”

“Intellectuals”: Sometimes I feel nervous and need to wear blindfolds?

Jin Dongyan: Now I see that this virus is replicated in the lungs and cannot be effectively replicated in the upper respiratory tract. It is not as high as the common cold. The sputum produced by coughing in the lungs may be more effective than sneezing and spread more virus. Therefore, the disease is not as spread as common cold, flu, smallpox, and tuberculosis. If it is such a strong transmission, we can’t stop it, at most it is slowing down or delaying.

“Intellectuals”: How many days, 14 days, from infection to symptoms?

Jin Dongyan: If we look at a cluster of infected families studied by the Hong Kong University team, it will only take 2 to 6 days, which is not very long. In general, the possibility of transmission after two weeks is small. Of course, this also needs to be researched. Has anyone spread the virus after he got sick?

“Intellectuals”: In addition to droplet transmission, it seems that feces also spread?

Jin Dongyan: Many coronaviruses, including SARS, are thought to be present in feces. Whether or not a new type of coronavirus is present is worth studying, but at least there is no clear evidence that feces are the main route of transmission. Mainly droplets.

“Intellectuals”: Suspected contact but no symptoms or mild symptoms. Isolation at home for two weeks, can it be basically determined without worrying about transmission to others?

Jin Dongyan: Right. For patients with mild or mild illness, not all can be brought to the large hospital. The reason for the panic was that it felt terrible. Of the 451 cases reported from Wuhan to Hong Kong, only eight have been confirmed for the new coronavirus, and the others are influenza and other common respiratory viruses.

Wuhan is currently at the peak of influenza at the same time, so most people are actually not new-type coronavirus infections, but flu. People infected with the new coronavirus are also mild and moderate. If all flu patients and mild patients now take up valuable medical resources and run to large hospitals, the crowd gathering may be even worse.

Now especially for the mild patients, I agree with the need for home isolation. For example, through online expert consultation, give them medical and even psychological counseling, and give them comfort. Infectious diseases and clinical virology experts should tell everyone how to isolate and give them It is suggested that there are even some who can prescribe medicines and deliver medicines, which can greatly reduce the pressure on the central hospital.

“Intellectuals”: Hospitals are also under great pressure now.

Jin Dongyan: As far as I know, nucleic acid diagnosis has become a bottleneck. In terms of diagnosis, for example, combined with chest X-rays, use effective methods to find out those patients who are really sick, severe, or at high risk, gather them for treatment, and leave scarce medical resources to them. The fact that patients are graded and shunted is really deep. Our medical reform should also go in this direction, and we can’t drag the central hospital to death like this.

“Intellectuals”: The triage system in developed foreign countries is indeed different, but we Chinese people seem to be used to finding experts directly and rushing to the emergency department, especially when panic?

Jin Dongyan: The mentality and mode of medical treatment in China are very different from those in overseas countries. The first is to find acquaintances and the second to find the best hospitals. Anyone who finds the best hospitals dies the best hospitals. This is a deep question of our medical system. What should we do now? Now we still want the patients to be separated and separated from home, and then the medical staff will support them so that most of them will not be severely dragged to death.

“Intellectuals”: There is a recent study. Of the 41 patients diagnosed early, 13 entered the ICU and 6 died. What do you think?

Jin Dongyan: There are two concepts. One is case fatality, which means that the number of people diagnosed with the disease is the denominator, and the number of people who die is the numerator. The other is mortality, called mortality, and the denominator is the total number of all susceptible people, and the numerator is the number of deaths from susceptible people. 41 were diagnosed, 6 died, and 15% was a fatality rate, which was high. We speculate that the researchers in this study did not identify patients with mild or asymptomatic disease. Of course, to calculate the mortality rate, in fact, it will end in the end. After most people recover, it will be more accurate at that time. The mortality rate is certainly not as high as SARS.

“Intellectuals”: Is the current diagnostic method effective?

Jin Dongyan: The current situation is that there are more missed diagnosis than misdiagnosis. Generally speaking, it is rare that the first test is positive and the second test is negative. But is it possible to miss it? If the sampling is not good, it is missed because the sputum is in a deeper position. The best way now is to detect nucleic acids. But now it seems that the test is not available in Wuhan, and the psychology of many mild patients is also not going to the doctor, so it must be underestimated.

“Intellectuals”: If you have a mild isolation, you should also keep in touch?

Jin Dongyan: It ’s okay after isolation at home. This is the most likely situation, and some of it may change, so a doctor should give a little guidance. If it suddenly worsens, you can get it back for treatment, which is double insurance.

“Intellectuals”: Can’t catch up with vaccines or drugs now?

Jin Dongyan: In fact, the vaccine for this virus is not difficult to make, but the vaccine is also in a hurry, it will take some time to come out. Now the virus has not grown very well. If you want to make it a vaccine, you have to think of other ways, but there is no way out. There are many ways that may be effective. The problem is that when you get the vaccine, the epidemic situation may be It has ended.

Drugs can catch up. Some drugs that have been tried in the past, such as SARS or MERS, antibodies from patients in recovery, and some drugs with clear antiviral activity, such as interferon, can be tried. It can only be a special event, and the country may approve it sooner, and there are some experimental things to do, but this is not the most urgent, because most people will still be good and supportive treatment.

Preventing and controlling SARS mistakes is distressing

“Intellectuals”: What do you think of Wuhan’s closure of the city as extreme?

Jin Dongyan: This is complicated and has not been adopted in history. Now it is not to challenge whether it is correct or not. We now hope that the closure of the city will have the effect of closing the city, and also solve various secondary problems, such as the psychological problems of the people, including panic, retrograde escape, and some leave early. Now, some people hide their identity in the field and so on.

“Intellectuals”: Now that some hospitals are collecting medical supplies, such as protective clothing and N95 masks, do you feel that the supplies are not sufficient?

Jin Dongyan: In fact, generally speaking, it is enough to wear surgical masks correctly, not everyone needs N95 masks. N95 masks should be reserved for people who are likely to be exposed to large amounts of virus for a long time. The mass production of surgical masks in our country should not be a problem. Because of the panic, the people try to take the highest level of protection to grab the N95, but they do not use it properly. They want to wear protective clothing used by other medical staff. These are not needed.

From the perspective of public health and clinical virology, it is necessary to teach medical personnel and the public to use these masks correctly. We virologists are dealing with different viruses every day. Who would be infected by studying this virus? Unless it is a new virus, we have no idea how it is transmitted, and accidents will happen.

The new coronavirus is transmitted through droplets, and it can only be effectively transmitted under certain conditions, and it cannot be used for everything. For example, will eating spread? This possibility is still very small, it will not. The main thing is to tell everyone how to use protective gear correctly, not that you use the protective gear, you have everything. Human alertness is just as important as awareness of following general rules. During SARS, virus leaks also occurred in Beijing P3 Lab, Singapore, and Taiwan. That is to say, under the strongest protection of Gu Ruo Jin Tang, people are infected due to human negligence. These painful lessons still have practical significance.

“Intellectuals”: Then how to balance the protection and medical resources. It seems that the opinions of clinical virology and infectious disease experts are important. Is this currently lacking?

Jin Dongyan: Like an English-style system, such as the infection control director of a Hong Kong hospital, everything is under the authority of the director, and he will provide the most accurate information and methods to frontline physicians. The Department of Infectious Diseases in China is a small department, and everyone does not want to go. This is a deep problem. Since SARS has been given a little attention, but basically still relatively weak. Everyone wants to go to those higher education departments, and the infection department has a lower status in the entire hospital.

“Intellectuals”: What kind of doctors do not need to wear N95 masks?

Jin Dongyan: Generally speaking, for example, Chinese medicine and brain surgery, as long as there are no infected patients running around, the possibility of exposure to a large number of viruses is small, and N95 is not required. Studies in the United States suggest that physicians wear surgical masks and N95 masks have no effect in preventing flu.

“Intellectuals”: Patients come with other complications, is it also contagious?

Jin Dongyan: This is the most troublesome. For example, during the SARS period in Hong Kong, an elderly person broke his bone after wrestling and became infected. He ran to orthopedics and infected the orthopaedic surgeon. This is true, but now everyone is very alert and the possibility of accidents is greatly reduced. Being alert is good, but you cannot panic.

“Intellectuals”: Is there anything else I haven’t mentioned and you want to add?

Jin Dongyan: In terms of scientific research, research is actually a long-term process. Like SARS in 2003, everyone came to do SARS, and no one did it later. The trend of Chinese scientific researchers, instead of focusing on long-term accumulation and in-depth research, needs to be changed. After so long, after the epidemic came again, the mistakes of 2003 were largely repeated, and there were problems in clinical virology, mentality, technology, and handling. This is actually very sad.

It is imperative to deal with the emotions of people within the closed city, to guide them correctly about the disease and the virus, and to make the worst case clear. In fact, the worst is not so bad, and it is not worse than seasonal flu. Seasonal flu kills more people, is more toxic, spreads, and causes more damage.

Dongyan Jin is a professor in the School of Biomedicine of the University of Hong Kong and an experienced virologist with a strong interest in viral diseases and oncology. He sought to understand why viruses cause different diseases and how different DNA and RNA viruses invade the host’s innate immunity, which is the first line of defense for humans against these invading viruses.

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