Scientists have uncovered another clue to the origins of the virus that causes Covid-19, with cave-dwelling bats in Laos carrying a similar pathogen that experts suggest could potentially infect humans directly.
The virus has killed millions since it emerged in China in late 2019, and controversy continues to revolve around its origin.
Some experts say it is animal-driven, but others have pointed to the possibility that the pathogen may have leaked from a laboratory.
Researchers from France’s Pasteur Institute and Lao National University said their findings showed that viruses genetically close to the SARS-CoV-2 virus “exist in nature” among bat species in the limestone caves of northern Laos. , a neighbor of China.
Of the viruses they identified among the hundreds of bats tested in Vientiane province, three were found to closely resemble the virus that causes Covid-19, particularly in the mechanism for attaching to human cells.
“The idea was to try to identify the origin of this pandemic,” Marc Eloit, who heads the Pasteur Institute’s pathogen discovery laboratory, told AFP.
Eloit, whose team analyzed the collected samples, said key differences still existed between the viruses found and SARS-CoV-2.
But he said the work was “a big step forward” in identifying the origin of the pandemic, confirming the theory that the coronavirus that has spread around the world could have started with live bats.
The authors of the study, which has been submitted to Nature for peer review, cautioned that their findings suggest that the new viruses “appear to have the same potential to infect humans as the early SARS-CoV-2 strains.”
“People who work in caves, such as guano collectors, or certain ascetic religious communities who spend time in or very close to caves, as well as tourists who visit caves, are at particular risk of being exposed”, the authors said.
International experts dispatched to China by the World Health Organization (WHO) in January concluded that the SARS-CoV-2 virus most likely jumped from bats to humans via an intermediate animal.
A competing hypothesis that the virus was leaked from a lab like the specialized virology lab in Wuhan was deemed “extremely unlikely,” though it has yet to be ruled out.
Martin Hibbert, Professor of Emerging Infectious Diseases at the London School of Hygiene and Tropical Medicine, who was not involved in the Laos research, said the most closely related virus was found to infect human cells “as easily” as SARS- CoV -2 and therefore could infect humans.
But he stressed that the virus “is not an ancestor of the pandemic strain.”
“This work confirms the expected diverse nature of coronaviruses infecting bats and increases the evidence that natural spread events from bats to humans can occur,” Hibbert said.
The authors of the Laos study, which has been published on the Research Square site, said their results suggest that the pandemic coronavirus potentially evolved through mixing between different viruses and bat species.
James Wood, head of the Department of Veterinary Medicine at the University of Cambridge, who was also not involved in the research, said it suggests that “recombination between different viruses was probably involved, rather than there being a simple evolution of a single lineage during a long period. ” ”.
In a comment to the Science Media Center, he said this not only underscores the likely role that bats and perhaps other animals living together play, but it also shows the “risks inherent in the wildlife trade,” where markets can help boost zoonotics between species. transmission.
from ScienceTechnology – ARY NEWS https://ift.tt/3u2o9ts https://ift.tt/3EFSYsG