Two studies published this Tuesday have concluded that the Covid-19 pandemic began in a market in the Chinese city of Wuhan, pointing to animal origin as a possible cause of the virus.
The first study is geographical analysis The first cases show thatDetected in December 2019, concentrated in that market.
Second trial Genetic analysis of the virus of the first casesShows that very The virus is unlikely to have spread widely among humans before November 2019.
The studies were published this Tuesday in the journal Science, reports Agence France-Presse (AFP).
The mystery of the origin of the SARS-CoV-2 virus
Since the start of the Covid-19 pandemic, there has been an ongoing debate among experts, which continues almost three years later to clarify the mystery of the origin of the SARS-CoV-2 virus.
One of the authors of these studies, Michael Worobe, a virologist at the University of Arizona, signed a letter in 2021. It has asked that the possibility of a leak from a laboratory in Wuhan be taken seriously..
However, with the data analyzed later, the scientist It now considers “it is not plausible that the virus was introduced through the animal trade in the Wuhan market.”As explained in a press conference.
Christian Anderson of Scripps Research Institute, a co-author of these studies, also said that while the lab escape theory has not been refuted, it It’s important to “understand the possible scenarios and what’s possible.”.
The study analyzed the residences of the first 155 cases
The first study looked at the residences of the first 155 cases identified in December 2019.
Researchers have shown that Cases clustered around the Wuhan market, unlike those recorded in subsequent months, which coincided with more densely populated neighborhoods. Additionally, in the cases studied, Those not directly connected to the market lived closer than those who worked or had recently moved there. This indicates that they are probably infected due to their proximity to the site.
The scientists analyzed samples taken from the market in January 2020, for example from cages or carts. Analyzes showed Sars-Cov-2 positive samples are concentrated in the southwest of the market, Precisely where live animals were sold (including raccoon dogs, badgers or foxes).
oh An animal that may have acted as an intermediary Between bats, coronavirus carriers, and humans, Not identified.
Before February 2020 there were two strains of the virus
The second study was based on an analysis of the genome of the virus that infected the first people. That concludes the analysis Two strains of the virus, A and B, existed before February 2020 And these Two lineages may result from two separate human transmission eventsNeither is the Wuhan market.
Previous studies have suggested that Lineage B is derived from line A. Scientists warn that It is important to understand where the animals sold in the Wuhan market came fromTo reduce future risks.
Although the ‘grey areas’ remain, the The researchers emphasize that information about the beginning of the epidemic is too detailed.
“There is a general feeling that there is no information that can tell us anything about the origins of the Covid-19 pandemic. This is incorrect“Underlined by Christian Andersen.
China is constantly accused of failing to cooperate fully with international investigations or of concealing information. Understanding how the epidemic started is critical to preventing similar future events. And could save millions of lives.
“So We don’t need to name a person responsible for epidemicsBut We ask you to understand them“Christian Anderson finished.