When Chinese scientists announced the new virus in December 2019, attention turned to Wuhan. So far, what do scientists know about the origin of the virus that causes the pandemic?
According to the Guardian, a year ago, Maria Van Kerkhove – a virologist of the World Health Organization (WHO) – was on Christmas holidays with her family in America. As usual, she checks her email inbox so she doesn’t miss any potential dangers.
“There are always warnings and signs of suspicious cases in the world. In the last few years, we have Mers (a respiratory syndrome that originates in the Middle East). There is always some sign of serious things coming up, ”she said.
Virologist Maria Van Kerkhove of the World Health Organization (WHO). Photo: Reuters.
Checking email and news about suspected viral infections is part of this routine of Van Kerkhove and many other experts such as Christian Drosten (German), Marion Koopmans (Netherlands), experts from mechanical engineering. UK Public Health Agency (PHE) as well as the US Centers for Disease Control and Prevention (CDC).
A series of cases of unexplained pneumonia have been reported in China in mid-winter. The email forwards a post from ProMED, an ISID alert network, an International Society for Infectious Diseases ISID.
On the evening of December 30, the Wuhan Medical Committee issued an online “emergency announcement”, alerting all medical facilities to be on alert and implementing their emergency plans. The agency pointed to suspicious signs of an outbreak of a disease at the South China seafood market.
“We think this is something that needs to be taken seriously. We activated our system immediately, ”said Van Kerkhove. Since then, she hardly had time to rest.
Within a few days, scientists knew it was not Sars, Mers, flu, legionella or any other illness ever discovered. This is a new pathogen.
Van Kerkhove is a respiratory specialist who has studied many types of corona viruses, including Mers. At WHO, she is responsible for explaining the course of the Covid-19 epidemic twice a week during the meetings.
“I immediately thought this could be a new corona virus. There are hundreds of thousands of corona viruses hidden in animals, ”she said.
Difficult to trace the origin
In fact, the corona virus has appeared in the WHO epidemic’s detailed development research plan since 2003, when Sars appeared.
By the time Van Kerkhove received an email about the post from ProMED, in Hubei province, at least 124 people were infected, some from mid-November 2019. Some people died. Out of 124 cases, up to 119 people live in the provincial capital – Wuhan city. The remaining five people all came to this city before falling ill. At that time, we still do not have any effective defense against this disease.
In Wuhan, there is an international stature biological laboratory. That makes this place quickly become the biggest suspicions about the origin of the new virus. However, these are only conjecture conjecture enough, because until now we have not found patient number 0, and probably never will.
Ebola epidemic in East Africa has also caused extreme panic to human health. However, we know her first victim was a child named Emile Ouamouno, who died in Guinea in December 2013. Ebola is very dangerous, but unlike any other infectious disease before. This makes detecting new diseases and finding solutions easier and faster.
Covid-19, on the other hand, resembles other types of acute pneumonia, and does not produce any obvious symptoms in the first days of incubation. The discovery work is therefore also more difficult.
The first clue of the disease is the Hoa Nam seafood market. Out of the first 41 confirmed cases, 70% were the stall owners, employees or regular customers of Hoa Nam market. This is a market specializing in selling seafood and live animals, many species are caught from the wild and illegally slaughtered. However, the first patient discovered did not have a clear connection to the market.
A corner of the South China seafood market in Wuhan, China, which is suspected to be the origin of the Covid-19 pandemic. Photo: AFP.
The market was closed by the Chinese government on January 1, 2020 and was thoroughly cleaned and disinfected. This helps in safe cleaning but destroys the potential clues here.
However, subsequent tests showed signs of the virus in wildlife captivity areas in markets. At the end of January, the market announced a wide range of wildlife remaining at the Da Zhong store, including wolves, yellow cicadas, scorpions, tufts, squirrels, foxes, civets, salamanders, turtles and fish. crocodile. This shop also sells animal parts such as crocodile tail, belly, tongue and guts.
However, up to now there is no solid evidence that the virus originated in this market. It’s possible that the virus came from an infected person shopping here. According to the latest assertions from Chinese state media, they believe that a foreigner has entered the market and spread the disease to the community.
“Even though China was the first to detect the infections, that doesn’t necessarily mean the virus originated in China. The origin of the virus is still in the process of tracing and it could be related to many countries and regions, ”said the spokesman for the country’s Ministry of Foreign Affairs, Mr. Trieu Lap Kien, in a meeting in November. 2020. However, this viewpoint did not win much trust from the world public.
The WHO has been investigating since the outbreak of the epidemic. Ideally, right from the discovery of the first infected people, home-based, patient-to-patient, family and colleague investigations should be conducted in Wuhan in January 2020.
However, at that time, the whole city of Wuhan was quarantined. At the time, the world didn’t seem to know what we were about to face yet, said Bruce Aylward, a Canadian doctor and epidemiologist appointed by the WHO to lead the fact-finding mission in China earlier this month. 2, said.
“From the moment I arrived in China, I knew I was facing something very serious that the rest of the world was not aware of,” said Mr. Aylward.
When he arrived in Wuhan, he was amazed at the seriousness of China in considering the outbreak of the disease. They shut down comprehensively, including the border closures. At that stage, China did what it needed to do. However, they only try to stamp out the disease, not proceed to trace the source of the virus immediately.
Is Sars-CoV-2 really bats in China?
On January 11, 2020, Chinese scientists gave the world an invaluable clue. On the day the first death was recorded, they released the genome sequences of the new virus. Scientists have named this new virus Sars-CoV-2.
That sequence and many other genomic sequences have shown that Sars-CoV-2 is at least closely related to the virus commonly found in the leaf-nosed bat in Yunnan province, China. Samples collected and stored since the outbreak of Sars 2003 showed that the bat virus RaTG13 resembles 96% of the virus that causes Covid-19.
However, that much information is not enough. In March 2020, virologists Eddie Holmes, Andrew Rambaut and colleagues published their conclusions and evaluations in the journal Nature from the data collected at that time.
Specifically, the new corona virus mutant protein has a “receptor binding domain”. This binding domain has the ability to attach to a certain receptor called ACE2, which is present in human cells. The bat corona virus does not have this binding domain, but the corona virus in Malay pangolins does.
Sars-CoV-2 was found in pangolin. Photo: AP.
Pangolins were immediately on the suspect list. However, it was never mentioned in the list of species kept in captivity or sold at Hoa Nam market – the first place where the disease broke out.
This summer, WHO conducted a formal investigation to find out about species capable of transmitting viruses to humans, and whether there are permanent reservoirs of the virus before the outbreak of the disease.
According to the analysis published in July, the scientists said: “To date, susceptibility studies (to the corona virus) done in a number of countries have indicated that domestic cats, weasels dew, hamsters and mink mink are especially susceptible to infection. Cats can be infected with viruses and transmitted to others. Of the more than 100 cats in Wuhan that were tested, nearly 14% were identified positive for the virus. It has also been found that mink infected with a mass virus in Denmark, the Netherlands, and then elsewhere in Europe and America. They have been destroyed.
Despite the genomic clues, many theories towards China still emerge. There are even more allegations that the Sars-CoV-2 virus was created in the virology laboratory at the Wuhan Institute.
This information has been officially disproved in the journal Nature through the studies and evidence that the scientists put forward. The first author to refute this theory was Kristian Andersen of the Scripps Research Institute in California. “Through analysis, we confirmed that Sars-CoV-2 is not a laboratory-born structure or a purposefully manipulated virus,” she said.
Josie Golding, a health expert with the Wellcome Trust, said: “A lot of researchers agree that Sars-CoV-2 is not a lab product, because no one created one. viruses that have too many associations with viruses found in nature ”.
Golding revealed that she also worked at a laboratory in Pirbright, Surrey. Such places often have specialized equipment, which helps to prevent as much as possible the laboratory structure from leaking out. Therefore, she confirmed that it is impossible for the new corona virus to accidentally escape from Wuhan laboratory. Most likely, animals infected with the virus and then transmitted to humans.
However, no matter where the Sars-CoV-2 virus originated, the advantage of China and other Asian countries is that they seriously considered it a serious threat from the outset, and since then have tough France. Meanwhile, Mr. Aylward said Western nations were not clearly aware of the seriousness of the problem from the start. And for him, that is exactly the reason why most Western countries have not been able to overcome the pandemic after nearly a year of facing it.