05/07/2020 - 17:49
- Clarín.com
- World
How did the new coronavirus appear and then pass from the bat to man? "A piece of the puzzle is missing," estimates researcher Meriadeg Le Gouil, coordinator in France of a research project on the origin of the pandemic.
"No one can say that they understood the emergence of this virus," stresses in an interview with the AFP agency this virologist and ecologist from the University of Caen (in western France), a member of the Research Group on Microbial Adaptation (GRAM) .
"In this coronavirus, we found traces of various viruses that we know in the wild . Except that we don't know recent parents, only their cousins," explains this 39-year-old researcher, who rules out a "synthetic origin" of the virus , for example, in a Chinese laboratory, as the United States denounces and denies Beijing.
According to the vast majority of researchers, the coronavirus was transmitted to man by an animal. Chinese scientists pointed to a market in Wuhan City, where live wild animals were reportedly sold.
Using genetic analysis, science was able to link SARS-CoV-2 to a virus studied in 2013 in a bat in Yunnan, southern China , similar at an average of 96%.
While direct transmission from bat to man is "possible," it is not, however, the most likely hypothesis, according to this coronavirus specialist, since close, numerous, and frequent contacts are required for a virus to make a species jump. .
"Unless absolutely gigantic bat trafficking is discovered in the past three years," he says.
"The second option would be to breed another wild animal," which would have served as an intermediate host between the bat and man, explains Le Gouil. "A piece of the puzzle is missing," which may not be the pangolin, as some suspect, but the civet cat, he says.
The researcher already encountered this small mammal during the epidemic caused by another coronavirus, the SARS of 2002, the subject of his thesis six years later.
"The civet cat is like our roe deer (in France), a dish that is prepared for big occasions," he illustrates. "He is a carnivore close to the dog and the cat (...) that frequents the caves, and that occasionally bats a bat."
The breeding of this animal "had multiplied by 50 in the five years preceding the emergence of SARS. The civet cat captured in the wild was brought to" specific farms, "which favored the birth of a variant of the coronavirus, present only "in this second group, adds the researcher.
Today, Chinese scientists "publish 10 scientific articles daily, but not a word about farms in the region. It is surprising for (a country) sensitized to the emergence of coronavirus."
"I would give anything to go and take samples in China of all the types of farms that existed in the region three or four months ago," he says.
The Discover research project that he coordinates aims to trace the SARS-CoV-2 track, studying the prevalence, diversity and evolution of coronaviruses in different species in northern Laos and Thailand.
"The objective is not necessarily to find the missing piece, which may have already disappeared. But we will have clues and a handful of arguments to better understand what happened," he explains. "At least we will have a very good view of what happened just before."
It is also about "detecting dangerous practices" for health, such as breeding civet cats.
"There is clearly a link between the overflow of human activity over wildlife, the way we interact with nature and the emergence of pathogens," he says. And he concludes: "We clearly see the relationship between the health of ecosystems and human health."
Source: AFP