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Where does COVID come from?WHO begins investigation, but faces challenges



The scenery before the closure of Wuhan Huanan Seafood Wholesale Market.

Early COVID-19 cases were related to a meat market in Wuhan, China, but investigations have not yet found samples of coronavirus in the corpses.Credit: Alami

The World Health Organization (WHO) has issued its plan to investigate the origin of the COVID pandemic. The search will begin in Wuhan City-Wuhan is the Chinese city where the novel coronavirus SARS-CoV-2 was first discovered-and will expand in China and other regions. Tracking the path of the virus is important to prevent future virus spills, but scientists say that the WHO research team faces a daunting task.

Most researchers believe that the virus originated in bats, but how it jumped to people is unclear. Other coronaviruses also come from intermediate animal hosts; for example, the virus that caused the severe acute respiratory syndrome (SARS) outbreak in 2002-04 may be caused by dogs (Arabidopsis) Or cit.

“Finding animals with SARS-CoV-2 infection is like looking for needles in the world̵

7;s largest haystack.” Angela Rasmussen, a virologist at Columbia University in New York City, said they may never find a “smoking stick” or Other animals. “For researchers, it is vital to establish cooperative relationships with Chinese scientists and government officials.”

It may take several years to thoroughly investigate the origin of the virus, and the investigation must be conducted in a highly sensitive political situation between China and the United States. Linfa Wang, a virologist at the School of Medicine at the National University of Singapore School of Medicine in Singapore, said that US President Donald Trump has always “called it a Chinese virus, and the Chinese government is doing everything possible to prove that it is not a Chinese virus.” Wang said that the political irrational game means that important details about the ongoing research in China have not been disclosed. Wang was part of the WHO’s 2003 mission to explore the origin of SARS in China.

He hopes that the situation in the new US administration will not be so turbulent. President-elect Biden also stated that he will reverse the withdrawal of Trump from the World Health Organization. Wang said that the support of China and the United States will “create a more positive environment for research in this field.”

Search starts in Wuhan

An international team of international epidemiologists, virologists and researchers who will have expertise in public health, animal health and food safety will lead the World Health Organization’s COVID-19 investigation. The agency has not yet released their names.

The WHO stated that the team held its first virtual meeting on October 30, including a meeting with Chinese researchers, and is reviewing preliminary evidence and formulating research plans. The agency said the preliminary investigation in Wuhan may be conducted by researchers already in China, and international researchers will travel to China after reviewing these results.

In Wuhan, researchers will carefully study the South China Meat and Livestock Market, which has been visited by many people who were first diagnosed with COVID-19. What role the market plays in the spread of the virus remains a mystery. According to the report on November 5 of the WHO’s mandate, the early investigation conducted a sample survey of frozen animal carcasses on the market, but no evidence of SARS-CoV-2 was found. However, most environmental samples taken from sewers and sewage did test positive for the virus. The report pointed out: “The preliminary study did not produce reliable clues to narrow the scope of the study.”

The WHO task force will investigate wild and farm animals sold in the market, including foxes and raccoons (Prosilo) And sika deer (Japanese cervix). They will also investigate other markets in Wuhan and track the journey of animals across China and across borders. Researchers will prioritize animals known to be sensitive to the virus, such as cats and minks.

The research team will also look at hospital records in Wuhan to find out if the virus spread before December 2019. Researchers will interview the first batch of people confirmed to have COVID-19 to understand where they may be exposed, and will conduct tests in the weeks and months before December, from medical staff, laboratory technology People and farm workers collect blood samples to look for antibodies against SARS-CoV-2. The report acknowledges that some of this work may already be carried out in China.

long term plan

The preliminary investigation in Wuhan will provide references for longer-term research on the origin of the epidemic, which may allow researchers to enter outside China. The World Health Organization report pointed out: “The place where the epidemic was first discovered does not necessarily reflect its origin.” He pointed out that before the first batch of cases were discovered, a preliminary report of viral RNA detected in sewage samples.

This statement can refer to a study1 pieceRaina MacIntyre, an epidemiologist at the University of New South Wales in Sydney, Australia, said that the paper was posted on the preprint server medRxiv without peer review. The paper has been retrospectively tested on Spanish sewage samples since March 2019 and found SARS-CoV-2 fragment. She said: “If this research is correct, we must ask about the virus in Spain in March last year.”

Wang said that considering the extensive surveillance of bats in China since the SARS outbreak in 2002, only distant relatives of SARS-CoV-2 have been found, so it is wise to plan to look outside China. Wang said that more and more experts believe that close relatives or ancestors of SARS-CoV-2 are more likely to exist in bats outside of China. He said that the WHO research team should conduct SARS-CoV-2 antibody surveys on bats and other wild animals and plants throughout Southeast Asia.

Martin Beer, a virologist at the Federal Institute for Animal Health in Rims, Germany, said that the investigation should also give priority to carnivorous mammals raised for fur, such as raccoon dogs and civet cats, which have played a role in the SARS epidemic. Bell said: “It is surprising that these animals are not mentioned in the report, and we have not obtained information from China about whether these animals have been tested.”

They said a spokesperson for the World Health Organization said that the visit will be guided by science, and it will be open-minded, iterative, and will not rule out any hypotheses that might help generate evidence and narrow the focus of research.


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