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It was a difficult mission and it ends without a definitive conclusion, but it provides important details.
The international team sent by the World Health Organization (WHO) to China to investigate the origin of the covid-19 pandemic concluded its stay in the country with a press conference in which it revealed some keys of its conclusions.
“It didn’t change our understanding [sobre el coronavirus], But we certainly know more about him”Said Peter Ben Embarek, head of the WHO mission and zoonoses specialist.
Its investigation lasted about two weeks and was tightly controlled by Chinese authorities, who initially resisted the mission amid calls by the United States to be more transparent and criticism from Beijing of Washington for “politicizing” the issue. .
After months of negotiations and once in the country, the WHO ensured that Chinese experts on the ground had been open with them.
We summarize the first conclusions of the WHO announced during a conference of almost three hours.
1- A laboratory leak is “extremely improbable”
At the press conference, held in Wuhan, the head of the international mission rejected the theory that the virus had leaked from a laboratory, an argument that Donald Trump’s administration insisted on without presenting any evidence and which has is the subject of conspiracy theories.
Specifically, the Trump administration has pointed out the possibility that the virus could emerge from the Wuhan Institute of Virology, one of China’s leading researchers in the study of level 4 pathogens, which require highest degree of biosafety, and that he was one of those designated by the authorities to analyze the genomic sequence of the new coronavirus.
After visiting this lab and others, Embarek highlighted the “strict safety protocols” in these types of facilities and argued that prior to the outbreak of the virus “no scientific publications or reports in any lab at world “had not mentioned it.
Leaks of this type are “infrequent”, they noted.
Therefore, the WHO team pointed out that this line of research not to be included in future studies.
2- Bats
The WHO team investigated four potential sources of the origin of SARS-CoV-2 transmission to humans:
- Direct animal-to-human transmission
- Transmission by an intermediate animal host (from animal to animal then to man)
- Transmission through certain frozen foods in the cold chain
- Possible laboratory leak
“The researchers consider that the most likely is the second option and this line of inquiry has been prioritized, ”reported BBC China correspondent Stephen McDonell, who attended the press conference.
“Everything continues to point to a reservoir of this virus, or a similar virus, in bat populations“, seals Embarek.
However, they felt it was unlikely that it was found in Wuhan. The team therefore tried to find “other animal species that could have contributed to introducing the virus” in the Chinese city, as intermediate hosts.
“There does not appear to have been a great circulation of the virus in any animal species in the country”, where Chinese scientists have analyzed thousands of species without being able to identify specific carriers, he said. -he declares.
3- cold chain
Although transmission by an intermediate animal host “is the [causa] most likely and one that will require further study and investigation, “Embarek also considered transmission via certain frozen foods in the cold chain to be possible, although he said they did not know. great thing.
The zologist explained that the team had identified vendors in the Huanan “wet” market, which some were related of the first official cases of covid-19 and in which frozen animal products are sold, including wild animals.
“The possible path between any animal species of origin and the Huanan market could have been long and convulsive, including cross-border movements”
Peter Ben Embarek
Head of the WHO international expert mission in China and specialist in zoonoses
“We therefore have the potential to pursue this path and study the supply chain and the animals that have been distributed in the market,” he said.
Chinese officials have attributed the latest outbreaks in the country to frozen foods imported from overseas and people from other countries, suggesting the virus may have originated. in another nation.
“We know the virus can survive in conditions found in these icy, cold environments, but we don’t really know if the virus can be transmitted to humans,” or under what conditions, Embarek said.
Therefore, I would recommend further study on this area.
4- Antes de Huanan
The WHO team further revealed that it had not found “strong evidence” that the virus was traveling in Wuhan before the first cases were registered in December 2019.
“To understand the outlook for December 2019, we embarked on a very detailed and in-depth investigation into other cases that may not have been detected until 2019,” Embarek explained.
“And the conclusion was that we found no evidence of significant outbreaks that could be linked to cases of covid-19 until December 2019. in Wuhan or elsewhere“, aadi.
However, Dutch virologist Marion Koopmans explained that doesn’t mean there weren’t any, the BBC reporter reported.
The first cases in the city did not occur only in the Huanan market, but also “simultaneously” in other places unrelated to this one, of which they did not provide further details on the trace.
In this regard, Liang Wannian, head of the Chinese expert team investigating SARS-CoV-2, pointed out that the virus may have circulated elsewhere earlier.
“In the two months leading up to December, there is no evidence that he was in the city,” Liang said, pointing to possible gaps in the detection of the virus in other areas.
WHO experts therefore said the study should be expanded to examine blood samples and tanks from animals in China and other countries.
“The possible path of any animal species of origin to the Huanan market could have been long and convulsive, including cross-border movements,” Embarek said.
Trace the origin of the virus, he concluded, it is a “work in progress”.
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